Preventing users from pouring water into coffee machine beans compartment | Hacker News Reader

Preventing users from pouring water into coffee machine beans compartment

ux.stackexchange.com

121 pointslaurent12345690 comments

This may sound dumb, but maybe the easiest solution is to put a transparent fake water container that never drains. So anyone who is about to pour water would see that the machine already has water.

Since the machine in question is hooked up directly to the tap, one never needs to fill it with water.

That's what I was thinking, but then the water would stagnate, go green, and be a potential source of mosquitos. So someone will want to change it.

The fix would obviously be to make a little bit of the water be drained away whenever a coffee was made, but then it would need refilling and you're back to a situation where you might as well just have 2 containers and disconnected from the water supply.

Since the false water container on top isn't going to be used anyway, what about just filling it with something hostile to microbes, like dilute hydrogen peroxide? If you wanted to get really fancy, you could even add a couple lines marked "max" and "min" and add some plumbing to make the fluid level vary between them.

Apart from the problem of having potentially toxic substances as part of a beverage generation device, adding extra moving parts to simulate a non-moving part is really adding unnecessary complexity, effectively trying to fight against the universe (and the idiots that it produces).

Instead of a liquid, it could be filled with solid plastic, similar to the fake glasses of liquid you see in joke shops.

And perhaps a subtle label on the surface, for someone who notices that the container does not really have sloshing-around liquid in it: "No water required"

How about the water container is transparent, and is actually used. Like a buffer containing water from the pipe. As it's used it get refilled.

I might be wrong, but it's just water, I don't think it can go bad unless it's got bad things in it. And keeping it sealed would keep away the mosquitoes. If that ever even becomes an issue.

The solutions that include an open air design for the bean hopper ignore the fact that oxygen is what causes beans to go stale. This is why coffee bean bags have a one-way valve built in: to let the CO2 out that is given off by the beans, and to prevent O2 from seeping back in.

And the solution to the problem is to install a barista.

This brings up a sad story from my old work.

We had a coffee machine where you had 2 containers, one for the beans and one for the water, never had a problem with knowing which was which. But there was also a place to put in pre-ground coffee, which we never used.

One day a consultant came along, and not being able to make coffee because the machine had run out of beans, they proceeded to pour beans into the space reserved for the pre-ground coffee. We found this out by the horrific gear crunching noise the machine had made as the coffee beans shredded the internals to bits. It was a disappointing and sad day for the engineers, many of whom were frequent coffee drinkers.

Needless to say after the machine was repaired we taped that pre-ground coffee access port closed.

That's a nice story of how a consultant have ruined the engineer's day.

You could also say it's a nice story of how a lack of documentation caused pain for both consultant and engineers.

And yet the premise of good UI design is that it should be self-documenting.

I was going to post something on their site, but apparently you have to have enough karma to give a response now.

Use a removable side-loading bean cartridge. The bottom of the cartridge would be mesh, the top open. There would be a spring-loaded door on the side of the cartridge that the machine would open once inserted (or it could be opened via a "lock" lever for a pure mechanical solution) so that beans could flow out. This way it could never be loaded with water, and the beans would stay fresh since once inserted the cartridge would be sealed on top and bottom by the rest of the machine.

This has already been suggested more than once on the site, which I suppose is exactly why they protected it. :P

(Even the joke answers, such as adding a "coffee bean pipe", are already covered in the stackexchange thread.)

I actually somehow haven't jumped on the StackOverflow bandwagon yet. If you need karma to reply to questions, how do new users get karma?

Only specific questions:

“This question is protected to prevent "thanks!", "me too!", or spam answers by new users. To answer it, you must have earned at least 10 reputation on this site.”

It's basically like semi-protection on Wikipedia: things which have gotten a lot of attention can get lots of noise, so only more established users are allowed to add content.

All you need is to design your bean enclosure so it's never completely empty. The few beans trapped in what I'd call a "reminder reservoir" will be enough to remind users beans go here.

If you can do this and keep the beans segregated, this is far and away the best solution.

Even just gluing a coffee bean or two to the outside might work.

or rather than having real beans, have fake beans at the bottom. I'm assuming that at some point the real beans in the reservoir would go off

"a brief hand-crafted manual"

You deserve your problem if you use that terminology for whatever people are not reading.

Eliminate the bean compartment and dispense the beans from a centralized location just like the water. Either using an augur or a pneumatic tube delivery system.

The best part about this solution is the inevitable conspiracy theories about the Government fluoridating our beans.

Thanks a lot, as it is early in the morning here, you just made my day start better with a little laughter.

Clearly the next step is eliminating the coffee machine and desperate coffee itself from a centralised location.

The coffee snob in me wants to say that for a nasty automatic machine like that, putting water in the bean hopper and breaking it is probably a good thing! Seriously, used commercial machines are fairly cheap and will make a far superior coffee which is worth twenty seconds of work.

But if you must, I like the idea of a bean container that must be removed to be filled. Better than warning labels (that people will ignore) or putting a picture of a bean there or something.

We have a proper machine in the office and some people still drink ugh instant. At least with a machine like we are discussing people will drink a better standard of coffee than they otherwise would.

>some people still drink [...] instant

They probably just don't know how to operate the machine.

Hence me saying that a automatic machine isn't the worst thing in the world . . .

I actually know people that prefer the taste of instant. I think it's one of those things where if you're raised on garbage, you'll like the taste. I know for a long time I though Tim Hortons coffee was the tits.

The coffee machine I have in my house does not have this problem. It is a very common machine, and there are many like it.

Here's one much like it: http://www.mrcoffee.com/Product.aspx?pid=7645

You take the carafe out. You fill it full of water. You open up the top of the coffee machine, and you have a choice:

You can pour water into the reservoir, or you can pour it through the filter basket and thus on to THE FLOOR because the carafe is in your hand.

People learn quickly how to use it.

Here's a commercial one with a similar lack of problems: http://www.amazon.com/33200-0015-VPR-2GD-Pourover-Commercial...

The water goes in the top. In order to load ground beans you have to pull out the filter basket. No confusion possible. Trying to pour water into the filter basket results in water on the floor. Instant feedback.

The coffee machines in question have a container for un-ground beans which are ground internally and brewed. So your interaction with the machine is limited to adding beans, adding water, pressing a button (and 90% of the time it's just pressing the button since it holds enough beans&water for several brews).

You're just linking to an average drip machine, which obviously doesn't have these problems, but it doesn't help the stackoverflow user who had the original question. The machines he was asking about have a separate container that stores beans that are automatically ground. These are fully automatic machines where you push a button and coffee comes out, no interaction is needed by the user, and yet the user will sometimes "think" action is required and will mistakenly fill the bean storage with water.

Your "commercial" drip machine is probably only a few hundred dollars at most, but the fully automatic machines are in the thousands of dollars, so repair is pretty expensive.

Why not actually fix the problem.

If people put water into the bean compartment then don't kill the machine. How you ask:

Water bypass valve used in Cold Air Intakes to prevent your engine from drinking water.

https://www.google.com/search?q=cold+air+intake&hl=en...

Have a fine mesh on a 45 degree angle that will allow the whole beans to slide down the mesh, but that water will pass straight through. The beans slide into a permanently covered bean receptacle that is impossible to add water to without disassembly (which should be an option for cleaning).

Beneath the mesh you could have a catchment to collect small bean particles and any water that the user tries to add, and the design and placement should be quite obvious that water poured onto the mesh isn't going anywhere. Conversely, let it collect there and go nowhere. If that catchment overflows, it goes onto the counter.

This was proposed, but especially if the bean capacity is large getting the beans wet is a big no-no. It also does nothing to dissuade users from adding more water for whatever reason (until it overflows). Thus you get potentially moldy beans, and a tray full of gross old water.

Several proposed perforated containers for the beans, but what I had in mind is a wire mesh similar in spacing (but not shape) to this:

http://upload.ecvv.com/upload/Product/200801/200631654352537...

Only a serious idiot would ever try to pour water on that. The beans slide down the wire mesh into the main bean compartment which is otherwise inaccessible.

Some machines have a wire filter like that to stop objects getting into the water tank; users might misinterpret it. I still really prefer the ones where you have to take out a basket, which is obviously not capable of holding water, and fill it with beans. Sealing it and getting the beans is harder.

For a user to misinterpret and pour water on what biot described would require such a fundamental misunderstanding of common sense and what I can only hesitatingly call "physics", that I don't think it is possible to protect the machine from such a user - except, perhaps, to hope that they will be foiled by the doorknob whose operation they must decipher in order to enter the break room.

A fine mesh is also great at directing a fair amount of water along the flow of the mesh.

The mesh wouldn't need to be that fine if it just had to exclude whole coffee beans.

I think I'd use a bottomless bean bin that pulls out with a handle. While it's pulled out, it's over a grid that lets water pass through (and ideally makes it clear that any water added is just going to be dumped right on the counter). When it's pushed back in, the beans fall into the actual bean reservoir.

The key advantage of the mesh is not to perfectly prevent water from flowing along it, but to be something that even the most caffeine-deprived user would not accidentally try to pour water on. Even if it does nothing mechanically to prevent water from entering the machine, it will psychologically prevent misuse.

Sounds good in theory, in practice you'll end up with dirty water and humid beans. Suboptimal...

I worked at a place where someone (who we never caught) put some chocolate coffee-bean-look-alike candy from Trader Joes in the grinder. All the new peeps (myself included) got 'blamed' for being ignorant, and lots of signs went up. I hate signs because the can never anticipate all scenarios.

My next work place had someone try to cook bacon in the toaster oven. As it turns out, this is not a viable way of frying bacon and it caught the toaster and part of a cabinet on fire. Later that month the building management started doing regular fire drills. We'd take the opportunity to tell the story about Mike and his bacon as we stood on the street.

I'd say people were idiots, but that's a negative view practiced ineffectively by the first place. I'd rather see it more like people incorrectly assume what they are doing is right, and never question if its not. Silly humans.

Signs are also stupid because they're built on two faulty assumptions: one, that the morons read them, and two, that the mistakes of the future will be carbon copies of mistakes of the past. There's no bacon frying sign over the toaster oven at my work, and I've seen people cook bacon in the kitchen. But there's a sign over the sink listing things that shouldn't go down it, as if nobody has one of these things at home.

My previous workplace had someone attempt to cook a ribeye steak in the toaster oven.

It actually worked, but management was angry the third time he pulled it and set a flat no-meat-cooking policy on the toaster oven (enforced via clipart signs).

I cook bacon in the toaster oven all the time... it's the best way. As long as your toaster oven can maintain 425F / 215C constant temperature (rather than having the element on permanently) you end up with beautiful moist but cooked bacon without it being crispy and burnt.

Wouldn't a label for this suffice? Who's going to read a manual only to find out that this is connected to the internal plumbing?

If it's obvious enough, it won't need labels. In fact, the right way to design these kind of products is to assume the person using it cannot read.

Perhaps a label and a "no water" symbol? Like this: http://thumb15.shutterstock.com/thumb_small/290671/290671,12...

That sounds like madness.. The doors that way!

Use a padlock. Put the key where only knowledgable users can find it. This will cut down on your casual visitor screwing things up.

Engineer a dyson-vacuum-cleaner-like apparatus which 'sucks' water and beans in different ways.

Do the first comment's ideas, but make it a two-stage event - first is to put the item on the grid/flap, second is to manually fold the gridflap into the machine, where it's dumped into a temporarily unsealed beanbox. Water won't stay in the grid long enough to hang around for the second stage.

Create a sniffer that requires the scent of a fresh bean to be presented before opening the port.

Drink hot chocolate instead

Sell special iron-laced beans and use a magnetic apparatus.

A label saying "This container is for coffee _ _ _ _ s" with a lettered padlock (http://wordlock.com/padlocks/) would perhaps be preferable to the hidden key solution.

I'm going to bring up the Microsoft Starbucks machine again, as it has also solved this problem. They used the 2nd solution - a water line directly to the machine. Also, the beans-hopper holds 2 kinds of beans, usually house blend and decaf, which rarely go empty at the same time.

No worries about watering the hot chocolate powder hopper, either. says "Hot Chocolate" on the compartment lid, and inside it's covered in chocolate dust.

Read a little more closely: the machine in question has a direct water line but people still occasionally put water in the bean compartment.

My theory: http://news.ycombinator.com/item?id=5175098

I'm not sure if you've seen one of these coffee machines. When you come to one, your first thought isn't "where do I put water", it's "what kind of coffee do I want?"

Here it is, to the right of a Keurig coffee pot: http://static3.businessinsider.com/image/4ef3bec5ecad04cd2c0...

The article already has a picture and it is a bit different than that.

Even with machines where you have to put the water in you don't have to do it for every cup, most likely people either put water when they put in beans, because that's what they are used to, or perhaps when the machine isn't working properly and they are trying to get it going again.

We have a cafe style coffee grinder (next to our manual espresso machine) that has two hoppers: one for the beans, and one where the ground beans end up, from which you dispense into the porta filter.

I am guilty of filling the wrong hopper with beans (talking instead of paying attention). Twice. Not quite as bad as water, but still a PITA to pour everything out and separate the beans from the ground coffee.

hire smarter people? I've never heard of this happening; I didn't know people could be that dimwitted.

You've got to remember: we're talking about people who haven't had their coffee yet.

Not long ago I discovered that the coffee machine works better when you put the cup in place BEFORE pushing start.

How about a visible warning sticker "Don't pour water here" (ideally with a pictogram for people who can't read)?

"Programming today is a race between software engineers striving to build bigger and better idiot- proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning."

The machine is fine. Your users are broken. Make the person that destroyed the machine pay for it.

I don't know what goes on inside the coffee bean hopper, but fundamentally I can't see why one couldn't just prevent the machine from breaking if the user does make a mistake. The machine could then warn the user of their error and allow them to correct it. They'd soon get the idea.

Load the beans from underneath using a detachable tray with a mesh inlay which will is used to pull the beans in.

(If you must go all out, put a bob that opens a trap in the bottom of the tray so they can't get the water near the machine if they try to fill the tray with it.)

This is full of very serious answers. I thought this was a rhetorical question to highlight the tendency of software developers to mismanage risk.

I feel like no matter what the answer is, the questioner could just throw another "But what if..." on top of it.

Set a post-it note saying "Water here". But what if a Black Hat gains access to the coffee machine and moves the sign? Etc. You can't win unless you know what the questioner wanted to hear. I guess that makes it a good interview question.

Adding to that, regarding a comment on that thread: "It'll probably still be gotten wrong by the same people who push on 'pull' doors". Culture is very important. In my native language, 'push' actually means pull! I will always get that wrong unless the design is good, meaning there's only one handle and it's on the side you actually need to pull. If there's an handle and the word 'push' just by its side than I'm going to pull it no matter what.

What language is that?

I usually fail at glass doors when PUSH and PULL labels are transparent so that I read "PUSH" and (reverse) "PULL" simultaneously.

Portuguese, "puxe": http://translate.google.com/#pt/en/puxe

X sounds like SH.

a coffee machine like this is guaranteed to make terrible coffee. the solution is to have better equipment.

if you see a coffee machine that has bean storage, it's almost guaranteed to suck.

Don't put the coffee machine next to the sink or water cooler.

Simple elegant and effective. If it takes one second to transfer water from sink to machine, you only get one second to process the data and possibly get the wrong conclusion. If it takes 60 seconds to walk across the room, that provides time to think ... why did they make it so hard to add water to this thing? Plenty of time for data processing to kick in and notice ur doin it wrong

I'd put a transparent foil on the beans container that shows, well, coffee beans. That way it should be obvious what it's used for, even if it's empty.

Don't have any opening to fill in beans or by mistake water, Get beans in a sealed container, sealed with cardboard at the bottom, which the machine can penetrate. Another solution is to connect bean jar through a pipe to bigger source of beans similar to how water is sourced. The bean source is maintained by a dedicated person. If they cannot learn how at use it,restrict access thats the way to go!

Make holes in the beans compartment that are too small for the beans. That would make it very obvious that pouring water there is pointless.

I have a saeco odea, they designed the bean recipient so it looks more like a curved plate than a bottle : http://imgur.com/CJzJLQ3 .

I think it's quite obvious to the user you don't put water in this.

On the other side, the water tank is a bit hidden, being inside the machine, behind an opaque face. Making it transparent would probably help.

I can easily envisage some people putting water in the bean hopper simply because they couldn't find anywhere else to put it.

So... Where I used to work, someone once put milk in the water container, 'cos they thought that's how you get frothed milk.

What about making the coffee receptacle resilient to water?

Let the water filter through the bean mechanism without damage. Catch the water in that bin under the cup.

Worse case you overflow the bin, but you learned a lesson and didn't break the coffee maker.

Which company would ever stop this from happening? More breakages = more money.

Make the hopper transparent and stick the picture of beans to it so that it looks like it is filled with beans. It makes it obvious and gives an immediate adverse reaction to someone trying to pour water.

As someone who actually has a major in product design, that link and this thread is pure gold!

I'm getting the same dark satisfaction as if I were reading how to write your own encryption algo at phpscripts.com

...time to make some popcorn.

Surely this needs needs Mr. Bean pointing finger.

For lots of stuff along these lines, Donald Norman's Design of Everyday Things is highly recommended.

Try a passive aggressive note yet? Humiliation is a fantastic break room tactic.

I don't subtlety works on the target demographics.

Just give everyone a training course for using the machine.

French press, anyone?

Keurig machine in the kitchen here. I'm sure it offends the coffee-snobs, but it works for me (I drink tea, not coffee, so just use it for hot water).

No offense taken ;).

It's just that there is a lot of thought wasted solving a derivative problem that could be avoided by continuing to use a simpler solution to the first order problem. This is classical overengineering. At the same time, any good solution to the coffee problem will likely have to find a tuned balance between a number of traits and they will be different for each person.

There are certain abstract tradeoffs that aren't taken into account in the OP (if I remember correctly). In the case of the keurig machine, it solves the complexity and convenience by narrowing flexibility, increasing expense and maybe sacrificing taste (which are all completely valid tradeoffs). The french press or a ceramic dripper maintain the flexibility, expense, taste and minimize complexity at the cost of convenience.

I don't understand this: "Typical coffee machines have two user-accessible compartments - one for water and one for coffee beans".

No they do not. Most "Typical coffee machines" require ground beans in a basket. The coffee maker described as typical is actually something I have never seen before.

Try a Kuerig if you want a cool coffee maker! But they again are not "typical coffee machines".

Reply on news.ycombinator.com