‘Perpetual broths’ that simmer for decades | Hacker News Reader

‘Perpetual broths’ that simmer for decades

atlasobscura.com

241 pointsdrdee173 comments

Kind of related to this is the concept of "Brunswick Stew." Look it up if you want a more accurate description, but as I recall, the idea from Colonial times in America is that there'd be a tavern/inn with a fire, constantly running, and a big cauldron of stew always topped off and ready for weary travelers. The idea is that they never "finished" a batch. They just perpetually added leftovers and foods that were at risk of spoiling.

It's like a Soup of Theseus... it's always the same stew, but it so gradually evolves, the flavour changes, the ingredients change, but there it is.

The concept feels incredibly cozy to me, both in practical and conceptual terms.

also known as hunters pot / stew. Essentially the same thing as thing as the broth, but in stew form: https://en.wikipedia.org/wiki/Perpetual_stew

I've actually done this myself in a crock pot for up to a few weeks at a time. The order you add stuff makes a difference. You don't want to toss in fish or anything with real strong flavors too early in your run or it funks things up for a few days. Much as the concept is fun, soup/stew every day gets weary pretty fast. Fun for short bursts in the winter though.

Perhaps i'm geeking this out too much, but I guess it depends on ingress-vs-egress and drawdown....but...doesn't including nearly spoiling food risk the whole stew going bad in a few days? Or do the constant simmer prevent that?

I don't know. I'm not sure the historians fully know. This concept might even be apocryphal to an extent. What I have learned is that the concept evolved (like so much cooking does) from what I described into a "it's actually now a recipe that people prepare once."

Something else I learned is that back in the day, people had different expectations for food quality. We would regularly eat rancid meat (many BBQ sauces were specifically built to hide/safen up rancid meat). And maybe while the concept was "it's always going", there were practical things we like to exclude from oral/written tradition, such as "well... actually we purge it once a week otherwise it goes completely bad." Who knows!

> well... actually we purge it once a week otherwise it goes completely bad

I know that when I cook stews I often end up with a lot of food bits stuck and eventually burned at the bottom and sides of the pot. I can imagine keeping it going by pouring the stew contents to another pot so that I could clean the first pot though. Without doing that... those stuck & burned bits will certainly add "flavor" to the stew.

> ...those stuck & burned bits will certainly add "flavor" to the stew.

Cooking fuel from wood was expensive to procure, so if I were making such a stew I'd cook it low and slow to conserve precious wood, so maybe they "cooked" over coals back then.

If I were to do this today, I'd top off with lots of water before bedtime so there won't be burnt bits in the morning. Maybe try to seal the lid edge with dough that can be used as bread in the morning to sop up the stew (might need to do 2-3 batches of such bread to make the supply of it last through the day).

I'd also likely use a rocket stove, a pot heat exchanger [1], and hot water pipes on the inside and outside of the rocket stove exhaust port to extract out as much working heat as possible.

[1] https://www.youtube.com/watch?v=q1j1RI3D7Zk

This stuff is known as "fond" and it's commonly used to make flavorful liquids (stock/broth).

Wonder if the word fondue is related to fond.

https://en.m.wikipedia.org/wiki/Fondue

I first read about fondue in Asterix in Switzerland (IIRC). Good fon(due)!

#PunIntended

There is fond (which can also burn) and then there is charred debris. The former adds umami, the latter tastes like cigar ash.

> Without doing that... those stuck & burned bits will certainly add "flavor" to the stew.

Pretty sure you're joking, but very likely they will. A limited amount of little charred bits taste quite good, and unless there's serious issues with heating or composition, it's not like it's going to overwhelm the rest of the flavors.

> This concept might even be apocryphal to an extent.

I've been to a pub in rural Cambridgeshire that had this on the menu. I made them laugh by asking what was in it and was it vegetarian.

I don't know if they were legally allowed to have it, but they did have it.

>...We would regularly eat rancid meat (many BBQ sauces were specifically built to hide/safen up rancid meat)

I think the idea that spices were used to cover the taste of rancid meat is generally considered to be a myth.

>...One myth needs busting here. Contrary to what you may have read, sauces were not invented to cover the smell and taste of spoiled meat. Spoiled meat tends to make people sick or dead, so, although covering it with a sauce might make it more palatable, people who used this strategy probably tried it only once.

https://amazingribs.com/barbecue-history-and-culture/barbecu...

An influential source that promoted this idea was a 1939 book by J.C. Drummond. Those as this review of the book shows, Drummond provided little evidence for his assertions and made errors like misinterpreting the meaning of words like “greene”:

http://www.medievalcookery.com/notes/drummond.pdf

> Spoiled meat tends to make people sick or dead

I'm not defending the sauces and spices hypothesis, but in times of scarcity (how most of our ancestors lived most of the time), starvation kills more people than spoiled food, and people ate a lot of spoiled food. Who knows how many it killed, but the survivors were the ones that ate it and made it.

Cheese, after all, is spoiled milk.

Almost all dangerous bacteria develops in temperatures between 40 and 140 degrees, so as long as you keep the stew hot enough it's likely to be fine: https://www.fsis.usda.gov/food-safety/safe-food-handling-and...

To add to this, the ones that survive outside that range are typically anaerobic and can't survive being exposed to air, so that makes it even less likely to be a vector for food poisoning

2 ways bacteria/fungi hurt people: excreting toxins or by colonizing us.

The 140 degree rule basically stops all colonizers since anything that lives in those temps probably isn't planning to infect us.

But some extremophile that takes hold in the hot soup could still excrete toxins that build up over time

I'm not sure there's anything in the intersection of: "grows in boiling water" , "exists outside of the deep sea or other exotic places" , "hurts humans" and "is at _all_ common".

If there is, it has to be a really short list.

Food goes bad when either there are microbes growing in it (you get sick from infection), or there have been microbes growing and those microbes have left behind toxins (you get poisoned).

Nothing can remain alive in a boiling pot of stew, the few things that can survive have very specialized habitats. So the only things you have to worry about are non-living poisons: toxins and prions. Since these by definition cannot reproduce, it’s only a problem if the food was spoiled before it went in the stew.

The chance of encountering a toxin goes to 100% as more and more food is added, but it will be dilute, no different to consuming food just before it goes bad.

Spores will survive boiling, that's why autoclaves (pressure cookers) are used in medical research https://en.wikipedia.org/wiki/Autoclave.

But spores are in a state of dormancy, so if you never stop boiling the broth, then spores never grow into anything. The most dangerous thing would probably be to boil the broth in stops in starts

Depending on the circumstances, boiling in stops and starts may not be too bad: https://en.wikipedia.org/wiki/Tyndallization

That is amazing! So basically you trick the bacteria into exiting their spore/dormant phase before you hit them again with another boil.

It seems risky because if you ever let the spores divide at all then you introduce further variation and a selection process into the mix, which could be disastrous.

But that reminds me of the "shock and kill" strategy used to get HIV out of its latent state before killing the virions: https://clinicalinfo.hiv.gov/en/glossary/shock-and-kill-stra...

And I guess this effect is also why chemotherapy drugs work best on fast-growing tumors.

I've heard from a friend of a friend that mycologists soak their grow mediums for a day or two to give spores a chance to germinate before pressure-cooking the whole thing. But said friend never called it Tyndallization. That's the thing I learned today!

Before refrigeration people were a lot less picky about what was considered spoiled food. One of my grandmothers would never look at the dates, but just trusted her eyes, nose and tongue as to whether something was fit for consumption or not, regardless of how much it was past the 'best before' date.

Best before not bad after

The labels include "best before", "sell by", and "use by", and they don't mean the same thing.

This is a great listen/read:

https://www.npr.org/2022/07/28/1114335397/expiration-dates-l...

NPR Expiration dates lead to lots of food waste, though these dates vary widely by state July 28, 20225:14 PM ET Heard on All Things Considered

Back in my dumpster diving days, I discovered how useful the sense of smell can be. Surprisingly, using it to detect bad food also changed the way I enjoyed good food. It became very pleasurable to eat fresh food!

It works most of the time, but not always, traditions around food are important. Rice is particularly insidious, rice grains carry Bacillus cereus spores that germinate after cooking. The trouble is that that particular bug grows at fridge temperatures and generates a heat-stable exotoxin. Any prepared rice older than 24 hours has the potential to give you really roaring diarrhea, even if it doesn't taste off.

Good tip, thank you!

Wait so even if rice goes directly from the cooker to the refrigerator, it should be eaten within 24 hours? I break this rule all the time, no diarrhea yet

yeah, weird... i reheat leftover rice all the time, both plain or say pilaf leftovers, and haven't had any problems yet...

Good luck to both of you.

had to actually look that up:

According to FoodSafety.gov FoodKeeper App, leftover rice can be stored in the refrigerator for three to four days

(my foodkeeper said 4-6 days)

and the FDA is typically on the paranoid side of things, like recommending to toss chicken in a couple of hours.

The British NHS is much more conservative, they recommend one day: https://www.nhs.uk/common-health-questions/food-and-diet/can...

Food poisoning from improper handling of rice is sufficiently common to have inspired studies on the risk. Here's one that's thorough from an age when public health still mattered: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2130471/. The meat is on p. 440 - 10^5 - 10^8 colony-forming units is danger territory. Note - it's not the bacteria themselves that cause symptoms, it's an exotoxin that sends people to the bathroom, don't kid yourself into believing you "have immunity" or something.

It's really a mystery why the government is so incautious with the matter, food poisoning in the very young and elderly is life-threatening. If you are young and healthy you'll survive, but for 48 hours it's a beastly experience that you are better off without. My theory is institutional capture by business interests, after CDC shortened COVID isolation guidelines upon the insistence of the airline industry no one should ever believe a word from them ever again. Imagine people went off rice - it's big business in Arkansas!

Came here to make a Ship-of-Theseus dad joke, beaten throughly to the punch.

Same. "Soup of Theseus" is an amazing term.

It’s ok, just add a bit more orange juice or whatever. ;)

I think the coziness of this recipe might be tempered somewhat by the fun food-borne illnesses that would have to spring up doing this.

I think if it is brought to a boil every hour it should be safe-ish

how do they manage to avoid that in the article? they list at least three different restaurants that serve these long-running soups, surely they don't poison their customers?

The article mentions keeping it at or above 200 degrees.

As others have said throughout these comments, as long as you keep the temperature high constantly, it won't be an issue.

Bacteria won't survive in simmering water, so time alone will not cause it to go bad. The toxins that bacteria produce can survive, which means tainted ingredients being added might spoil it, but as always, the poison is in the dose. With a large enough pot, a couple pieces of spoiled food likely won't cause illness.

My dad would tell me of roadside chili houses in the southwestern USA (Texas, California, etc.) that always had a pot of chili going that they would ladle out to hungry travelers. The meat in the chili supposedly varied according to what was available: usually beef, pork, or roadkill.

Interesting idea. Really fast food because it's so slow.

Huh. I am a relatively recent (11 years) transplant to Virginia and had never heard of Brunswick Stew until I moved here, where lots of people make it (it's "traditional") but I have always found it to be thin, bland, and insipid, so I'll take the minimum amount to be polite at an event but otherwise avoid it.

But of course they're all making it fresh from a recipe. I wonder if the reason I'm finding it bland is that the true traditional version includes a range of flavours from all the previous leftovers? That seems very plausible to me.

Traditionally, the first step is making stock from a bowling-ball.

Stirring with the number 7 pin of course

My parents were too well-off for Brunswick Stew, so we had Titleist Bisque instead.

My wife hates it because growing up in North Carolina she associated it with hunters throwing in bits of meat from whatever their most recent kill was - rabbit, squirrel, maybe venison. Never know what you're eating.

It is just bland. I grew in southern Virginia and it was a fixture of wintertime and often sold by churches and fire departments. At best, it’s tomatoey and doesn’t have too many lima beans, but is always a bit gluey and the meat just sort of turns into little string of muscle fiber. Honestly it makes me a little queasy just thinking about it. Most of the time it seems to have been cooled for 2-3 days prior to sale, for what that’s worth.

I haven't had it personally, but one of my SO's tried a famous "perpetual stew" when in France and we talked about it at one point. Her description kinda matched what I'd expect from braises that I've let go to long: you end up with bland mush.

I think there's a reason very few restaurants serve this style of dish, and it's not because of health codes. We live in an era of insane abundance compared to the medeivil and colonial eras. A lot of historic dishes from those times just don't stand up to the expectations of a modern pallet.

It's a romantic notion but if you simmer anything for too long it'll just be generic food water at some point

It’s just old timey MSG.

How does this make any sense? The longer you simmer something, the more concentrated the remaining material becomes.

Volatile flavor compounds boil off as well.

The flavor breaks down and so does the food.

For example: boil potatoes for too long and more water gets into it. It'll kill the flavor and texture, so that the food tastes watery and the texture becomes soup-ey and wet.

> I think there's a reason very few restaurants serve this style of dish

It is in fact quite common in some parts of China, as the OP mentions. But it's just a stock, used in other dishes, not a dish of it's own.

> more specifically in the cuisines of Canton and Fujian, where there’s a rich tradition of making lou mei, or master stock, which is used to braise and poach meats.

I had read about this before, I recall an article about maybe a US restaurant where the chef had brought the lou mei over from China, and the sous chefs who were tasked with keeping it going. I can't seem to track down the article now. But my understanding is that in fact very many restuarants in China do this, it's standard.

Not sure about China, but I’ve encountered local restaurants boasting broth that has continuously been cooked for decades in both Thailand and in Philippines.

Yep.

The thing is you don't "drink" the stock (lou mei) because it's too salty. So the solid foods are taken out without much of the liquid, and when you've served all the food in a batch, you're left with ~50% volume of the stock. It's still flavorful, arguably even more so since it absorbed the other food flavors in addition to the original spices etc. So if you're operating a restaurant, you just keep the liquid, replenish it with a bit more spices and condiments, and use it again and again...

Nice, thanks for the context!

I hadn't totally realized you're cooking food in it, removing the food, then re-using the broth! i guess you must have to strain it periodically. That is admittedly a really odd practice to me! It seems like it's origin might be at least in part just to not waste the stock? But people really believe it is important for flavor? (I am not suggesting it's not, how would I know?)

thanks for your comment,

just a small correction, it's "medieval" and "palate"

"palate" is a physiological term which describes the roof of a beings mouth.

Edit: @NovemberWhiskey I didn't know it was a dual-purpose word, thanks for the correction.

No; "palate" was correct - it's a metonym in this case.

I've always thought of it more as a way to conserve the calories that food represent, rather than a delicious dish in its own right

Agreed.

It's not some ultimate dish, nor was beer some delicious delicacy.

These were techniques by our not so distant ancestors to survive in far less connected, far less hospitable times and conditions.

It can preserve flavor, but it becomes concentrated as the water evaporates away, so i wouldn’t say you should ever grab a bowl of just that.

Master stocks are used as a base in Chinese cooking the same way a lot of recipes already start from a stock; but it is rarer and rarer for home cooks to make stock from scratch and not just use a box from the store in the US. I have a lot of friends that categorically do not cook meat with bones in it. The Chinese one is also different from hunters’ stew in that it is a specific soup used as a base for future versions of said specific soup

Aromatics also tend to escape as well, not just water. There’s some good tests out there with venting vs non-venting pressure cookers for making stock

>It's rarer and rarer for home cooks to make stock from scratch

Pity, it's really easy and super delicious.

This past weekend my family was sick so I went to the store and got one of the deli roasted chickens (was in a hurry), pulled off most of the meat, and put it in a stock pot with celery, onions, carrots and some seasonings (S&P, fines herbs, star anise, bay leaves), and filled with water. Simmer for 3 hours, strain.

Amazingly delicious, pretty easy, and the chicken and dumplings I made with it turned out fantastic.

Pretty much any time there's a bone or carcass I'll use it to make something. Had a work lunch last week and I took the ham bone to make ham and beans.

LPT: Cook with bones.

"...concentrated as the water evaporates away"

on a long running stock, you would regularly add water to keep it from drying out.

A local restaurant had a minestrone soup that had been running for 10-15 years, until the place burned down.

It was ridiculously good. I think the key aspect that made it good was that they served it with every meal so it turned over a lot.

Do you know what they did on holidays? Did they just never close for any reason whatsoever?

We had a salad like that for a while but I think it was in danger of becoming a serious health risk after a week or so.

Yeah, you can only do it with hot foods that are effectively being constantly sterilised.

I just had my first cup of Brunswick Stew the other day. Extremely delicious and was as cozy as you said.

I worked, as a teenager, in a Michelin starred hotel in the U.K. - they had, in the kitchen, an enormous stockpot, as tall as a man, which must have held 500 litres or more of stock, perpetually simmering. There was a stepladder to get up to chuck stuff (bones, vegetable scraps, you name it) in, and it had a tap at the bottom to fill smaller cauldrons from. It was explained to me that it had been going since the 50’s. Not quite ancient, but pretty elderly.

Long shift on a cold winter night, nothing beat a mug or two of that stock.

Not quite the same as Ship of Theseus because the soup will never be fully replaced. The will always be some bits of the original – no matter how small – hanging around forever.

the dilution level is presumably not the same, so I’m nitpicking, but technically it could be like with omeopathy [1], where the initial substance can be so diluted it is guaranteed that there is no trace of it at the molecular level in the final preparation.

[1] https://en.m.wikipedia.org/wiki/Evidence_and_efficacy_of_hom...

Sounds disgusting and unhealthy. May as well drink stomach acid. There is something about freshness of food not just sterility.

Cozy is the perfect word and I find myself noting often that the things I naturally find to be cozy are related somehow to finding small portals of comfort in order to make surviving in a harsh world a little easier, developed by people over the millennia.

You can do this with whisky. When you have less than a couple of inches left, dump the remains into a decanter. Repeat with every bottle you buy. Occasionally drink some. Never let it empty.

It becomes your own personal blend, always changing. Lots of fun.

TWO profiled broths were destroyed by bombs in war. Apparently a leading cause of broth destruction.

> an even older pot, in Perpignan [France], had been bubbling since the 1400s until it finally met its demise in 1945 during World War II bombing raids.

> The broth [in Tokyo’s historic Asakusa quarter] would be going on 100 today, but the previous batch was lost in 1945 during World War II bombing.

1945 was not a good year for ancient broth, among other things.

I would expect a lot of long-running things are lost to wars or big natural disasters.

It actually makes me really sad to think that bombs destroyed the broth from 1400 AD.

I do realize this isn't much of a start on what WWII destroyed.

As a tavern owner, one might be prone to neutrality. One king is as good as another, as long as they leave you alone.

In dramatizations of wars we always see an army taking over a village and sucking it dry, but I suspect there would be some overlap of tavern locations and 'tactically bad places to get caught by the enemy', such that the officers might volunteer you for a free meal and then move on before enemy scouts tattle on your whereabouts. Certainly somewhere in the world there are roadhouses located in kill boxes and thus have operated independently and unimpeded for generations.

I’d imagine natural selection plays a part. Eventually after all the taverns in dangerous (for taverns, not individual humans) locations are ransacked, the site of locations the survivors were built in will enter the zeitgeist as “This seems like a good spot for a tavern.”

And floods, and forest fires…

I also like the "forever bottle" that is common with bourbon lovers like me. You take one of your nicer bottles and when another one is close to empty you don't finish it but instead dump it into a "forever bottle" that keeps evolving with the different leftover bourbons you pour into it.

You could call this your solera. Most famously, sherry, port wine, madeira, and some vinegars are made with a similar system used to blend ages.

https://en.wikipedia.org/wiki/Solera

Soleras are not perpetual. They just diminish volume over time and so are put into smaller casks until they are bottled.

“No container is ever completely drained, so some of the earlier product always remains in each container.”

https://wikipedia.org/wiki/Solera

Tangentially related would be Navy coffee, which sailors say is made in pots that are never cleaned and develop a "varnish" of sorts.

People say the same about Bialetti-style "moka pot" coffee makers. The reality is that any "varnish" is just old rancid coffee oil.

I think a pretty big component of it is protein? Mine only comes off with the special cleaner, or powdered detergent (not the liquid kind which is missing some anti enzyme cleaners) (or lots of scrubbing)

Polymerized oil seems more likely, similar to the impossible-to-clean gunk that forms on kitchen surfaces from cooking fats.

If it gets hot enough to polymerize, then it's probably essentially the same as a seasoned cast iron pan.

Given that 1) the coffee stays on top, away from the heat, 2) you boil water in them, which restricts the maximum temperature, and 3) they have rubber seals: unless you're disassembling them and popping them into the oven frequently, I very much expect the answer is no. Just rancid.

I will caveat this with "I am not a fan of moka pot coffee" though. I think it's usually awful. Better than, like, diner coffee, but still.

Indeed, for me moka pot is just one tiny step above percolator coffee.

I agree. People: clean your moka pots! If you believe the patina improves your coffee, test your theory: Brew a batch with just water, and give it a taste.

I used to believe in the "don't clean your Bialetti", but then one day I realised it's the same gunk that's in the bottom of by coffee machine drip tray. Yuck!

Navy cooks will bust the bubble promptly. They clean the pots religiously, the difference is that each cook treats the brew differently. If a cook left a vessel or had a mate make the coffee, sailors'll notice the change in treatment.

Also, you have to keep in mind, Navy coffee is a mythic thing. Taking on a spiritual character from being a source of constancy and solace in an otherwise stressful/hostile environment. It's a morale thing.

Makes me wonder if the coffee subplot in The Expanse was just a coincidence or someone had experience with Navy coffee, directly or by reputation. Holden just about cries when he has his first cup of Real Coffee from their salvaged Martian Navy frigate.

I call this an "infinity bottle." I mix both bourbon and scotch, too. Typically the last ounce or 2 of a bottle. Sometimes it ends up pretty meh, but other times it's fantastic. If I don't like the flavor, I'll come back to it in a month and see if it has mellowed out at all. I also keep list of what's in there taped to the bottle.

Just a note that I've found infinity bottles of Scotch don't work nearly as well as American whiskeys do; Scotches don't all play nice with each other (and I don't drink a lot of phenolic Islay stuff; I'm saying, like, a bottle full of random Speysides gets funky quickly.)

It will definitely depend on the scotch. I mixed an Ardbeg Uigeadail into the bottle and it changed it considerably, but not in a terribly bad way especially after it sat for a couple weeks. But I think that's part of the journey. Right now, it's pretty heavy on the Islay (peated) scotch so it is definitely a bit weird at times, but it'll change over time with my palette, and I like that.

For example, right now I'm really into blended whiskies like Wolves [0], and as such the infinity bottle is starting to change from that characteristic Islay peat/smoke flavor profile to a more American whiskey profile.

I've found that writing tasting notes help me enjoy a weird whiskey a bit more, which includes the infinity bottle.

(But I will admit -- I have wanted to dump the bottle before! In that case, I just topped with bourbon and considered it a soft restart.)

[0]: https://wolveswhiskeyca.com

You've now given me an idea to try - Islay with an American honey bourbon

Sorry, leftover bourbon?

I have nothing to add except for my somewhat amusing personal anecdote that this post was right above the post about "forever chemicals" when I clicked it. "Perpetual broths" would make a funny satire of "organic" packaging for "forever chemicals".

The details here are intriguing. It's also a kind of classic differential equation problem. I.e. take a desert lake fed by a small stream carrying dissolved minerals, which loses half its water by evaporation (removing no mineral) and half by an outflowing stream - what's the concentration of minerals in the lake relative to the feeder streams?

First, how long should you wait before adding fresh bones, vegetables, etc to the soup before serving it, if it's always simmering at 200F (94C)?

Second, what percentage of the soup is consumed per day? Taking one bowl out a 100-bowl pot of soup per day is vastly different from serving 90 bowls per day, then restarting with only 10 bowls left in the 100-bowl pot. This allows asking the question, "what percentage of the food added a week ago is still in the pot".

Also if you're adding bones I imagine the whole pot is strained from time to time to remove such solids.

It does mention sherry, but don't think it mentioned the process they use for that is called solera - https://en.wikipedia.org/wiki/Solera

It's also done with sour beer, but with a single vessel, http://www.milkthefunk.com/wiki/Solera has an interesting explanation 'to continuously make sour beer'

I’m not sure if the math holds up on this. Diluted over and over I doubt there is any of the previous remaining (enough to taste) and soup is boiling I assume so there’s no bacteria you are keeping going like with mole or sourdough.

I think the fact that there's no bacteria remaining is the point, since food preservation was a real issue then.

Aren't there autocatalytic oxidation reactions? There might be flavor effects from always having a pool of those ready to oxidize new ingredients.

Also the perceptual flavor effects of the associated story on the broth being old.

at least for soups, it always tastes better on the second day.

Yeah, I remember watching a YouTube video of a Japanese restaurant owner, who does the same thing: every day, he refills his broth pot to full, puts more bones in, and leaves simmering. He said that he only had to restart a decade or so because of tsunami induced flood.

Sounds cool, but then if you do the math, and assume that every day he uses half of the broth, then after only 10 days, there is only around a teaspoon of the original broth in it, after 20 days there is only around a single drop, and after one month, you only get a thousandth part of a single drop.

If my maths is correct, in the limit, after renewing half each day, the whole is on average a day old.

>Sounds cool, but then if you do the math, and assume that every day he uses half of the broth, then after only 10 days, there is only around a teaspoon of the original broth in it, after 20 days there is only around a single drop, and after one month, you only get a thousandth part of a single drop.

Shouldn't whatever is remaining still have some influence on the fresh ingredients being added?

The answer depends on whether you believe in homeopathy.

I love this math, thank you. Reminds me of homeopathy where if you do the math not even a single molecule of the original thing remains when they dilute it.

>Homeopathic dilutions beyond this limit (equivalent to approximately 12C) are unlikely to contain even a single molecule of the original substance and lower dilutions contain no detectable amount.

https://en.wikipedia.org/wiki/Homeopathic_dilutions

Reminiscent of Rincewind's roll-up cigarettes made from fragments of old roll-ups: "The implacable law of averages therefore dictated that some of that tobacco had been smoked almost continuously for many years now."

When I lived in Taipei many years ago there were a lot of subtitled Japanese food and travel shows. One time, the show profiled a small restaurant in southern Taiwan (Tainan or Kaohsiung, I can't remember which) where they had the same pot of soup broth going for more than a 100 years. Not just the broth, but the pot itself. It had a misshapen, oily hump on one side of the pot's edge.

This reminds me of Tim Power's historical/fantasy book "The Drawing of The Dark". It centers on a constantly used, very large beer brewing barrel where a magical dark beer accumulates at the very bottom over time. And it's only to be drank every 700 years.

A story in a magazine (when they had such things) of a young lady house-sitting, told of the soup on the stove that was 3 generations old. "Eat all you like; just throw a little something in to replace whatever you take!"

She ate some, threw some pasta in, too much. An hour later, the pot was a solid block of pasta!

So she threw it out, started over with some Campbells canned stuff and never told anybody.

Enrique Olvera, the chef of Pujol in Mexico City, has a dish that's just two kids of mole: one freshly made today, and one from a batch that was started the day the restaurant started, and has evolved each day since then. When I visited, it at day ~2000. The taste of both, the the contrast between them, is really quite remarkable.

British comedians Lee & Herring brilliantly satirised this in their sketch show in the 90's - https://www.youtube.com/watch?v=zfbhFA7JY_I

Reminds me of a place in Memphis called Dyer's Burgers. They've continually refreshed 100+ year old grease and reuse it for frying their food: https://www.roadsideamerica.com/story/44635

My wife is Cantonese and while we don't have any family heirloom broths, there are definitely weeks, especially in winter, where we just have a constant broth going for a couple of weeks. All the leftover veggie bits and bones and such get thrown in there as we go. The flavor is always different, usually good, sometimes a little odd, but then we just purposely put new food in to balance it out (an apple for some sweetness for example).

I gotta say it's nice to always have a pot of soup ready to go when it's cold.

Does it take a lot of electricity to keep your stove going 24/7 for weeks? Trying to get an idea of how much impact this could have on an electricity bill.

I was thinking to do this in a non-pressurized Instant Pot. Between the cover and the insulation, it might not use much power.

We do it in the Instant Pot, so it stays pretty hot. When we need to turn it off for a while we put it in jars, drop the jars into ice, then put them in the fridge. Then we just heat one jar a a time and add stuff to that.

So it's actually not all that energy intensive.

The nonsense about how the flavour gets more complex over time is just that: nonsense.

There's a video on YouTube where a hobby scientist takes a cup of water and doses it with an incredibly potent poison, a tiny fraction of which could kill. He then discards half the water, dilutes it, and repeats the process about 6 times. Finally he drinks the water and is totally unharmed.

The point is that after the pot's been half-emptied a few times, nothing remains of the previous mixtures.

Discarding just the half of the poison solution and doing it 6 times just dilutes it down to 1/64th of the original concentration. I guess the video you mention wants to debunk homeopathy, but the maths as you describe it doesn't work. (Homeopathy uses 1:100 dilutions, so that would be a different game. Indeed, I think I've heard that they don't even bother with diluting 1:100, they just discard the whole contents and use what's left inside accidentally.)

> There's a video on YouTube where a hobby scientist takes a cup of water and doses it with an incredibly potent poison

Cody'sLab Drinking Cyanide <https://www.youtube.com/watch?v=i6hOVhQQ9h>. Apparently it was removed because YouTube Trust and Safety didn't believe in dilutions lol

https://kaijutegu.tumblr.com/post/188783528423/heres-what-a-...

also, pope water!

Also brings to mind balsamic vinegar: there's a battery of casks, decreasing in size, and each year a portion of the biggest cask are transferred to the one below it, part of which has been moved to the next smaller-sized cask, and so on. New grape must is then added only to the biggest. The smallest cask is where the final product comes from (after a minimum of 12 years, for the "real thing").

Having some older vinegar in each of the casks significantly enriches the flavor, but also protects against bad years, since if the flavor of the grapes is a bit off one year, it gets balanced by what's already there as well as by next year's batch.

My grandma who is from.South Africa married a Liverpudlian and went over to Liverpool, where her husband had come.from.a working class background. She threw out their "forever broth" which drew the ire of her mother-in-law!

I'm reminded of ramen restaurants I've visited that tell stories about their broth and its origins, mentioning that it's been simmering for decades. Some of the more famous ramen places I've visited have gone so far as to point out that the broth is made offsite in case anyone was thinking about attempting to tamper with it. Maybe some of that is for dramatic effect, but I imagine if you're a competitive restaurant and your success is dependent on something decades old, then you need to protect it.

"170-180 years"! https://youtu.be/fpjFQoTWNUY?t=374

In the long run, you would likely have metal corrosion issues. Everything eventually dissolves, at least a little, it just takes a long time. Heat and moisture "forever" is a rough environment for metal. Consider metal parts dipped in a tropical ocean for decades, or the parts inside a nuclear reactor or steam plant. This is probably why you tend to hear about pH neutral broths and such instead of perpetual lemonade or perpetual pickles.

If you heat oils long enough they'll polymerize just like putting finish on cast iron. It might take 100 years instead of 100 hours but it'll polymerize eventually. The rancid taste can be avoided by serving fast enough that the average age of the food is reasonable. In general, with good mixing and fast serving, it can't get much worse than a couple days old even if the long tail is theoretically a century old. The whole topic is a good intro to distribution curve shape.

A perspective comment: Many people do this without thinking about it. I have a tin container I've been adding dry looseleaf tea to for perhaps a quarter century. I do try to run it out completely between adding batches of newer tea, but I'm sure there's some dust in there from the last century and its been in continuous use since then. My grandma had a perpetual dry granulated sugar covered dish, and a perpetual salt shaker on the table.

surely it's trivial to swap pots/cauldrons once in a while? the point is to keep the broth, not the cauldron

Anyone intrigued by the idea of meals and flavors evolving over time from leftovers should read An Everlasting Meal, which describes similar techniques.

https://www.amazon.com/Everlasting-Meal-Cooking-Economy-Grac...

In the recent weeks, monads finally clicked for me, and I was introduced to Christopher Alexander’s ideas on “unfolding” (and thus, generative patterns). (https://www.livingneighborhoods.org/ht-0/whatisanunfolding.h...)

It tickles me to see this in food. The article talks about how those flavor profiles change over time.

Peas porridge hot, peas porridge cold, peas porridge in the pot nine days old.

I used to routinely eat "glop" that evolved over about a week each time.

I started it the first day with some vegetarian rice or pasta concoction on the stove, served some, put the pan in the fridge, took it out the next day, added some ingredient (usually by sniffing it, and imagining what flavor would be good to add), cooked on stove again, repeat.

It usually ran out in about a week. It tended to taste better closer to the end of its lifecycle, but this was irreproducible -- I didn't keep notes, nor plan, because this was improvisational art, not engineering/science.

One day, I was telling a new roommate about my lazy improvisational cooking, and she mentioned her grandmother died from "that", so I stopped. Even if there wasn't a bad association, I'd have to learn about food safety, to be coloring outside the lines like that, which would be too much like work.

the important part is to never let your glop go below 60C in its entire lifespan. keep it in the oven, the pot, wherever, and leave the fire running until you finish it.

From a surviving poverty approach it really makes a ton of sense. You just throw whatever you have in the pot and that's breakfast and dinner. It sort of averages out nutritional content between when you have more money or less. More money and meat goes in, less money and just vegetables go in.

This is mentioned in passing in the article, but the Solera system used for Sherry and other things is similar in concept.

https://en.wikipedia.org/wiki/Solera

There is a local rumor that Chris' Hotdogs in Montgomery, AL has never changed the hotdog water. https://www.chrishotdogs.com/ Probably not true.

I don't think there's an emoji to represent my facial expression when I read your sentence.

In Mexico, there are some people who do this with Molé

Most famously now is Enrique Olvera of Pujol fame from Season two of Chefs table on Netflix.

I like many, grew up with some kind of stove top medley that'd be going for a while.

This one is excellent. I've eaten Wattana Panich, Ekkamai (วัฒนาพานิช-ก๋วยเตี๋ยวเนื้อ) as well. Pujol might be my favorite restaurant. It's not that hard to get a taco omakase seat at the bar.

This is similar to the solera method (https://en.wikipedia.org/wiki/Solera)

Anecdote: As i started my career in the world of IT in the early 00s at a local internet provider (started out as a BBS an did grow really good) where of one of the founders was rumored that he did never cleaned his mug since the early 80s, at least from the optic of the mug (and his office, which was the stereotypical hacker cave with empty pizza boxes etc.) i was tempted to believe it.

Also in Thailand (there seems to be many videos with different years of how old the soup is): https://www.youtube.com/watch?v=29RxjfH0H1k

Some podcasters talking about it: https://www.youtube.com/watch?v=uX2lUssXJpc&t=889s

There is an oft quoted phrase which is usually found online

"The cauldron was rarely emptied except in preparation for the meatless weeks of Lent, so that while a hare, hen, or pigeon would give it a fine, meaty flavor, the taste of salted pork or cabbage would linger for days, even weeks."

it seems like not an article about perpetual goes without those words. It gave me deja vu reading it.

There is finally a time to share my technical report, "Ensuring a Safe Perpetual Stew": http://jpreiss.github.io/fun/perpetual.pdf

TL;DR: Under reasonable assumptions, one should choose a stew volume such that half of the stew is consumed each day.

My father grew up (1930s and 40s) with a batch of soup always on the back of the stove. He moved away to university and then married my mum, a physician, who found the idea of that horrifyingly unhygienic.

He told me about this at some point when I was a kid, and observed that he was basically never sick after he grew up and moved out.

What does food science say about the safety of this?

Sound disgusting to me and a good way to get salmonella.

Imagine the goop stuck up the sides of the pot.

It seems like it's common sense, but the article points it out anyway: Keep the broth on simmer and put it in the fridge or freezer when not in use.

I had read about this sometime ago:

https://en.m.wikipedia.org/wiki/Pot-au-feu

one of my favorite things to drink is the broth you get at a good chinese bbq pork/roast duck joint. Usually consisting of pork bones, chicken feet, roasted chicken and duck carcasses, corn cobs, carrots (and occasionally tomato, peanuts, jujubes and black eyed peas) really rich stock, absolute comfort.

We do something like this at home. Not quite a perpetual broth, but a week-long broth. Re-boil it twice a day.

I suspect that the advantage of these perpetual stews is entirely in the marketing

> “I became an expert at hiding food from customs officials.”

and

> “Of course not. Americans can be so naive about cuisine. They would refuse to eat it. So I tell them after,” she admits with a laugh.

One wonders if the tone of this article (and the discussion here) would be so complimentary if the protagonist were an Asian or brown person...

Another one read the examples that included China, Bangkok, and Tokyo and the comments talking about mole.

Reminds me of the Stone Soup story from the original creators of Fractint.

Fractint is new to me (cool! this would be fun to build in javascript...) but I was thinking of the same story.

Fractint Mandelbrot Generator V17.3 - https://archive.org/details/MEDLEY_SE230215

https://en.wikipedia.org/wiki/Stone_Soup

Sounds like my coffee mug.

Wouldn’t having a propane burner on 24 hours a day be very expensive?

Also, does it really make that much of a difference? I feel like after a couple of hours with a fresh batch you could be right back where you started without really missing out on too much.

It takes a long time to pull flavor and nutrients out of bones.

Making a good bone broth takes about 24 hours of simmering. If you're going to be making 1 or 2 new bone broths every day, it won't require more energy to just have a perpetual broth instead to which you keep adding bones.

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