A partially-automated medium-throughput homemade cider press with lasers | Hacker News Reader

A partially-automated medium-throughput homemade cider press with lasers

biotinker.dev

121 pointsbiotinker40 comments

For UK readers:

USAians use the term "cider" to refer to what UKians call "apple juice". What we refer to as "cider", they refer to as "hard cider".

I have no idea what term USAians would use for spirits distilled from apple liquor, e.g. Calvados; or fortified cider, such as apfelkorn. I would be interested to learn.

I've never seen apfelkorn for sale in the UK, and Calvados is only available from specialist merchants. I don't know why UK apple producers don't make these strong apple drinks; it's not as if we don't grow enough apples here.

@schoen: Um yes, it's the "lasers" bit that dragged me to the article; that was clickbait. It's just about making fermented apple-juice at home. Which is not that hard; it will ferment all on it's own, you don't need to add yeast or anything. Cider is the natural end-state for apples.

  There was a young lady from Clyde
  Who ate a bad apple, and died.
  The apple fermented
  Inside the lamented
  And made cider inside her inside.

In my experience, cider is a bit contextual. I've heard and used it to mean both alcoholic and non alcoholic cider. But usually people default to mean a non filtered apple juice like you said. (Since we also have apple juice, but it's hard to think of it as anything other than super processed sugary drink)

Apple liquor/cordials are usually called just that, or more specific depending on the type of liquor (i.e., my family keeps a bottle of Apple flavored whiskey)

Things like apfelkorn probably just get wrapped up in the catch-all term schnapps, if not one of the above terms

Yes, schnapps.

"Apfelkorn" isn't actually schnapps, by my lexicon. I thought schnapps was basically synonymous with "obstler" - a clear, white spirit distilled from fermented fruit. I think of Himbeergeist, or Poire Willem. In Germany, it is legal to set-up a garden still, and make your own fruit spirits, without a licence; and that stuff can be very strong - much stronger than say a whisky at the bar. I've had this stuff served to me from a plastic watering can.

I believe apfelkorn is basically apple juice fortified with grain spirit (vodka, essentially). I think in some parts of Germany, it's customary to drop a shot-glass of apfelkorn into a litre-glass of pilsner (people do this with Jagermeister, for reasons I don't understand at all - why mix nice pilsner with nasty cough-mixture?)

There are sweet alcoholic products that are labelled "schnapps" that are more like fortified wine than spirits.

> apfelkorn is basically apple juice fortified with grain spirit

Here in the Upper Midwest (Minnesota, Wisconsin, etc), there is a similar beverage called Apple Pie that's made with sweet apple cider, high-proof alcohol like Everclear and other flavorings. It's dangerously delicious: the apple flavor masks the alcohol, leading people to drink far more than they realize.

Since the area has a high number of people descended from German immigrants, your post has me wondering if that's where it originated.

Q: What's worse than finding a worm in the apple you are eating?

A: Finding half a worm.

> I have no idea what term USAians would use for spirits distilled from apple liquor, e.g. Calvados; or fortified cider, such as apfelkorn. I would be interested to learn.

Where I'm from (southeast USA) it's just referred to as apple brandy if the ABV is ~40%. If you've got something like a very sweet and low alcohol liqueur (15 to 30% abv) then it'll generally be called Apple schnapps.

Generally - I take Apple brandy to mean "Apple was fermented to make this liquor" and Apple Schnapps to mean "This is some fermented sugar with apple flavoring added"

There is also applejack, which is apple brandy, but named differently because it used to be made differently. Instead of using a still, they'd leave it out in the winter. Ice would form on the top, which would get tossed away, and the brandy would be what's left at the bottom. Now, even if it's called applejack, they use stills for healthcode reasons.

Thanks, I forgot about "applejack". I didn't know it was a kind of brandy (Calvados is basically brandy). And I certainly didn't know it was traditionally made by freezing out the water. I thought it was just another name for fermented apple-juice.

So I am now better-informed (HN is a good place to get better-informed!)

> it will ferment all on it's own

Yes. I live on a small farm with lots of wild (I assume) apple trees. We used to have a horse that would only eat the apples on the ground, after they had fermented. You could watch her drunk ass standing there, swaying slightly!

Apparently animals getting drunk on fermented apples is a fairly common thing. Who knew?

Apple orchards and pig farms go together. Apple sauce is considered to go well with roast pork.

In some parts, it is customary [citation needed] to run pigs in apple-orchards to scrump the windfall, and to feed younger pigs on the pulp left over from apple-pressing. I know pigs like to scrump fallen apples; I don't know if they get falling-over drunk. I'm not a country-boy.

I was hoping from the title that the lasers would somehow directly contribute to the extraction of the cider, but it turns out that they're just used as optical sensors. :-)

That doesn't take anything away from this awesome project, though.

Hopefully by next year I'll have implemented the pulsed electrical field generator I mention at the end, and then I'll very much have solid-state electronics directly contributing to cider extraction.

From the intro, I thought they used lasers to replace the 'slicing' step. I'm fairly sure that strength laser falls into military grade though.

Apparently, subjecting pomace to a high voltage pulsed electrical field (30kV, 40us and 1kHz duration and frequency) will crack open intact cell walls and improve yields (archive) for both the tannin compounds in the juice, and also juice quantity in general. If anyone has ideas on how to home-build such a system, please reach out.

I think I'll stick to the old-fashioned way....

I must say I do enjoy the mental image of a mad scientist throwing a big old blade switch and browning out the neighborhood to....make cider.

Reminds me of that scene from Young Einstein.

Cool project, made me very thirsty and in the mood for eating an apple. Or three.

Stupid question from a non-native speaker: what is the difference between apple juice and apple cider? In my mind, you ferment juice to make cider, but the article calls the initial raw liquid coming straight out of the press "cider".

It's an americanism as far as I can tell - 'cider' is what would be called apple juice in the UK (or maybe just fresh pressed apple juice) and 'hard cider' is what would be called 'cider' in the UK (i.e. the alcoholic beverage).

That's correct in the most of the English speaking world, apple juice is what it sounds like, cider is fermented apple juice (as far as I'm aware, it is in the UK). In American English cider is apple juice, and hard cider is fermented, alcoholic apple juice.

Correct that we call it hard cider if it's fermented. For non-fermented, we draw a distinction between apple juice and cider. Best explained by Flanders: https://youtu.be/L1BfF77Pvio?t=15

Good question! Cider is unfiltered and cloudy, and gets a rich brown colour from the pulp sediment. Apple juice is totally clear, and has been strained of all sediment. As others mention hard cider is alcoholic, but most people just overload and use cider, and distinguish by context - which isn’t helpful. You can make hard cider from juice or cider, the flavour will differ, but it the name. However, most commercial cider is just flavoured malt liquor - which also gets the same name, so ingredient checking is important!

It also depends where in the world you are. Cider, in the UK and Ireland, is never anything but a fermented alcoholic drink.

This is a USA perspective.

Cloudy apple juice is referred to in the UK, and most places apart from the USA, as "cloudy apple juice". Cloudy fermented apple juice is referred to in the UK as "scrumpy" or "scrumpy cider". It's mainly made in Herefordshire and the West Country, and it can be surprisingly strong; in many West Country pubs, they won't let you order a pint of scrumpy, they'll limit it to half-a-pint, unless you are known (or have a local accent).

I have heard, but I don't know, that it was customary to chuck an iron ploughshare into the cider fermenting vat; it would completely disappear by the end of fermentation. I have heard a similar tale about throwing in a horse's head - nothing left, dissolves completely.

I'm sure they don't use these adulterants in the production of commercial "hobo cider", such as White Lightning. But vegan "ciderpunks" should maybe ask questions about the scrumpy they are ordering.

> customary to chuck an iron ploughshare into the cider fermenting vat; it would completely disappear by the end of fermentation.

I have trouble believing that this was customary. It's absolutely the case that iron will dissolve in a large vat of fermenting apple cider, but the result will be a cider with some very odd and unpleasant colors and flavors. Not something that someone would want to induce intentionally. Most cidermaking books will instruct one to keep the cider from any contact with any iron, copper, or lead as all three will readily dissolve.

I hear you!

It sounds like a bonkers tale to me (which is partly why I related it here). I've never tried to make cider, and I've never read a cider-making book. It certainly doesn't sound like the kind of hygiene practice that is normal in fermenting processes. But I do have the impression that hygiene is not taken as seriously in cider-making as in, for example, beer-brewing.

Cider-making does have inherently less hygiene standards than beer-making. The apples have been outdoors for their entire lives, and spraying them with water only does so much. The cider itself is acidic enough that it's not a terribly hospitable environment for many microorganisms that would flourish in, for example, beer. Freshly pressed cider has plenty of other microbes swimming around in it, and while Campden tablets eliminate some, much of the success of the fermentation relies on your desired yeast simply out-competing and denying oxygen to the others.

Beer, by contrast, is boiled for an extended period of time prior to fermentation. This gives a sterile starting point, but doing something similar to cider will radically change the flavor.

> The cider itself is acidic

Especially with scrumpy; it often (usually?) tastes pretty vinegary - not like commercial cider at all. I think it's much more refreshing and thirst-quenching than sweet commercial cider.

I like to cook with cider vinegar. It's refreshing, and relatively sweet. I'd say the difference between cider vinegar and scrumpy really comes down to a matter of degree.

It's surprising that vinegar is refreshing; but roman soldiers used to carry sour wine (vinegar) with their equipment.

And when a roman soldier (supposedly) passed a cloth soaked in vinegar to Jesus on the cross, he was passing him the most-refreshing thing he had - it wasn't some kind of sarcastic taunt.

You might be interested in different fermentation processes. A friend of mine has wild fermented, at pressure and low temperature (55F I think), a mix of Mac and Ida Red that ended up tasting delicious. He chucked in about half the campden tablets you'd need at his volume to leave some natural yeasts. The cider started off tasting sweet and being a good competitor for a Magners, and eventually became this very clear/tart flavor.

He uses a fancy and expensive SS Brewtech vessel and glycol chiller. I'm interested in duplicating some of this process using cornelius (corny) kegs with a spunding valve and possibly a used mini-fridge or basement for temperature control.

Fun project. You might be interested in belt presses - they can be hooked directly to the grinder reducing the time (and labor) of moving the pulp to the press. They also allow the whole process to run continuously.

Examples:

https://www.vigoltd.com/AdditionalDepartments/Processes/Appl...

https://www.cellartek.com/products/belt-press-ebp-500/

These are neat! I've been vaguely aware of them, but never looked into them too much. It's hard to find DIY plans online for that sort of thing, and I'm not sure I'd be able design my own from scratch well enough to be worthwhile.

In a similar vein, swap out the grinder for a shredder/wood chipper-type model. You will no longer have to cut the apples open, and you can fill it by the bucket rather than one-by-one. Much higher throughput.

To clarify, with the grinder I built described in the post, I did not have to cut open apples by hand any longer. It could shred apples as quickly as apples could be put on the ramp.

Just finished looking into these more. While they seem really neat, even if I home-built one it would be way out of my price range. Just the filter belts alone would cost more than this entire project did.

I bet if you call up Information Unlimited, they'd sell you what you need for a DIY pulsed electrical field generator. https://www.amazing1.com/pages/megawatt-pulsers/high-energy-...

Wow! Very cool site and products.

This looks very promising, thanks! I sent them an email.

I've never worked with anything higher voltage than 240V before, so having people with experience to whom I can ask questions will be very helpful. If it was 5v pulses, I could just PWM a mosfet, but up that voltage 5000x and all I would have is a lot of smoke.

Brilliant.

I could never avoid the metallic taste when I’ve pressed apples (on a much smaller and way more amateurish scale.)

I’ve always felt a bit cursed — like it’s impossible for me to press apples without introducing some kind of fault / taint.

I vicariously celebrate this project instead :)

The acid in cider will aggressively dissolve any iron or copper it comes into contact with, giving it a blue/green color and corresponding taste. One thing I ran into with my old press was some paint finish flaking off, exposing the iron beneath- is it possible that you had something similar, allowing inadvertent iron exposure?

For this project, every single screw or sheet of metal that touched the cider is made from food-grade stainless steel to prevent this issue.

Not the OP but, If you want to try out just the fermentation process, check out my series I did here:

https://youtu.be/0hnfhlurS90

There was that fall that I made a lot of alcoholic cider and then that December I drank enough of it to get a little bit dependent on it.

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