How can users be prevented from pouring water into the bean compartment of a coffee machine?

  • Typical coffee machines have two user-accessible compartments: one for water and one for coffee beans. Pouring water into the bean compartment kills most machines, the repairs cost a fortune.

    Now here's an improvement (Schaerer Siena-2 if that matters)

    Schaerer Siena-2

    this machine is permanently connected to the water pipe (like a washing machine) and so there's no water compartment, only a bean compartment.

    There's also a brief hand-crafted manual next to the machine explaining that the machine is connected to water, no water needs to be poured anywhere.

    Still some people try to pour water into the bean compartment.

    How can the design be further improved to prevent users from pouring water into the bean compartment?

    What about a hinged cover (hinge at the back) that has "BEANS" written on the inside with an arrow pointing down (or the appropriate icon)?

    Our office full of engineers came up with a solution to this: a sticky note that says "Do not add water to machine"

    @Jonas It'll probably still be gotten wrong by the same people who push on "pull" doors

    @Izkata: The difference is that they open the cover to reveal the message, rather than approaching an unchanging message from afar. If the door flashed "Pull! Now!" right when you touch it, the number of people getting it wrong may be smaller.

    add a dummy (transparent) water container that is always full

    Don't know much about the internals, is it conceivable to only allocate beans briefly with a hinging mechanism at the bottom of the compartment? If so you can prevent it from ever opening via two small contacts on the top of this hinge that would become active due to the conductivity of water preventing it from opening.

    Add a funnel at the back, with a hose that leads into the drain. That way, there's two places to put stuff, and the user is forced to make a choice. What's that? Yes, I'll see myself out.

    I guess they didn't get the memo about the new coffee machine.

    I haven't seen an office coffee machine in more than 20 years that wasn't hooked up to water. What planet did these people step off? Also, the machine looks a lot like a commercial espresso machine. Who ever heard of adding water to those from the top? When was the last time you saw a barista at a coffee shop pouring water into a machine? Academic Programmer #16

    @Kaz - I guess they're from the same planet as me ... The offices I've worked in, I've never seen a coffee machine hooked up to water.

    Fresh ground coffee with tap water? What if you have really bad tap water in your area?

    Now we've solved the water/beans problem, where does the milk go?

    Line the bottom of the coffee bean container with lithium.

    label with text: $500 fine - for pouring water here - it will damage the machine

    A small dummy compartment with a lid. The lid can't be removed, and has the text "No water required :)" (I think some of the other solutions with full sized dummy compartments are a bit impractical for a commercial product.)

    Use classical conditioning... When they add water to coffee beans, hit them with an electric shock.

    Why not use the same hole to pour both the beans and the water? Inside, there could be a plate at a 45 degree angle with perpendicular gaps through it that could let water go straight down through the gaps, and the beans would go off following the 45 degree angle into a bean compartment. This way, you remove the issue by removing the option to even screw up.

    Put a sticker of coffee beans around the transparent comportment of the beans so it is clear that coffee beans go in there. On the other hand, then you will be confused when the beans run out but it looks like it's full. So take the sticker off again. But then you're back at the initial problem with the water, so repeat endlessly.

  • You need the bean container or filling mechanism to communicate in its physical presence alone, that it will not hold water. Additionally, emphazising what is expected, coffee beans, in form of an icon might help.

    This is just a crude sketch to visually show what I mean by "physically" communicating that the water does not go in here. Devise the coffee bean filling latch in a way that has visible holes that will obviously let water through, but are small enough to hold coffee beans.

    enter image description here

    What this approach does is not only solve your communication problem, but at the same time this will eliminate the actual breaking of the machine by pouring in water, because the water will simply not run into the slot (my sketch is crude and I am no product designer nor engineer, but you get the point - make the right angles and curves and whatnot and it's simultaneously a physical impossibility to get the water in).

    P.S.: If you get rich implementing this I will insist on receiving a free coffee machine even though I prefer tea!


    Edit: With so many comments and @trisweb's answer, I felt compelled to refine my suggested design a bit:

    enter image description here

    • Make the depot a drawer, because drawers pose an even less intuitive choice for pouring water into (@trisweb's answer)
    • Then have the drawer (or its bottom part) be perforated (@JanSchejbal's suggestion)
    • Make the drawer have an explicit coffee beans icon (@Davejarvis's suggestion)
    • Make the drawer's front transparent, so users can see the level of coffee beans
    • Ensure no water can run into the machine, by making the back of the drawer seal the machine insides off when the latch is fully pulled out
    • Ensure air tight sealing of coffee beans when the drawer is closed (should be easy to implement with this design, as the perforated bottom can easily be covered when inside the machine - I imagine that engineering the bottom cover to partially slide off when inside the machine is a plausible way of retrieving the beans for grinding) (@Andrè's comment)

    Nice idea, but coffee stays fresher when stored closed off from (free circulating air). I suspect your design may reduce the quality of the coffee due to the constant ventilation. If the machine would be right next to, say, a water boiler (for the tea you prefer), the coffee beans may absorb the water vapor produced by it and end up clogging up the grinder.

    It's nice seeing some sketching in here for a change.

    @André the compartment could still be sealed when shut the important part is that it does not look suitable for water when open.

    @André jk.'s answer is what I had in mind. The latch to pour them in should be "perforated", but closing it would close the bean compartment... anyway, that's the engineering challenge then :)

    @André Would modifying this idea with a slide out bean container with a solid exterior face and a perforated bottom instead work? You can have an airtight seal without adding any extra parts and the open bottom should keep anyone from accidentally filling it with water.

    You could also decorate the slot with pictures of beans and a not-so-subtle arrow pointing in and down.

    @André Make a design that the little holes will only be open when the top cover is opened.

    I'd just like to remind everyone that if you create better and better idiot-proof mechanisms... the Universe will just create a bigger idiot. :P

    To address the concerns about air, similar to Dan's idea: make a perforated tube which slides sideways or diagonally into the machine, making it obvious that it could never hold a liquid but still sealing at the base. A diagonal insertion would also encourage people not to overfill the bean supply.

    The best design is collaborative! Great job pulling together lots of ideas into one quite elegant final result.

    give this man a free coffee machine

    I'd test that when somebody does still pour water in - that the holes are large enough to prevent it actually getting into the machine and killing it.

  • As you observe, connecting the machine to a water pipe removes the need to add water, but the need to add coffee leaves the user with one place to put water. So what we're looking for is a way to remove the need to add coffee; the user will then have nowhere to put the water.

    The solution: Mains piped coffee beans.

    +1 - However, would humbly suggest leaving the users no space for mistake and hiding the coffee machine from them entirely. Am going to put the steaming coffee pipe right into my office...

    Part of me wants to downvote because it is "Not a real answer", but the other part likes the idea of piped coffee beans so much that I just can't.

    Soon we'll be saying "You mean they lived in an age without running coffee beans? Inconceivable!"

    If you're going to have a pipe for coffee, why not pipe it in liquid form. Then this could actually be feasible if you ignore all the reasons it's not feasible.

    One step towards living in the Diamond Age.

    @Random832 Makes me think of Google's CTTH plans. Want!

  • Make the user open a drawer to place the beans inside. Once closed, the drawer simply opens into the bean container normally.

    Water almost never goes into a drawer.

    Especially not into a perforated drawer.

    My espresso machine has a drawer for water. It may be a poor design, but it does exist.

    Use a Drawer with mini holes on the bottom, before user manages to close it, his foot will be wet - he'll probably notice something is wrong then ;)

  • How about only one opening which leads the water into the water compartment and beans into the bean compartment?

    enter image description here

    The mesh would let the water flow through and the beans pour to the side.

    Love the idea, but when pouring a lot of water, you would likely get some into the beans, and get them wet. Moisture isn't good for coffee beans.

    Furthermore, this might reinforce the behavior.

    Overflow would be a big problem

    You need a pipe from the water compartment around to the front of the machine so the water flows straight out onto the person pouring the water in. They'll soon get the idea.

    You need a spill reservoir in a coffee machine anyway. Look at the picture in the question; the metal plate on which the cup stands is the top of that reservoir. Paul's objection doesn't make sense. If it's no longer a problem, then do reinforce the behavior.

    @JohnGB's comment is valid, but the idea is salvageable. The bean compartiment should be mechanically sealed off when the top lid is open. Imagine the vertical line to the left of the mesh to be that seal. Now connect that to the mesh, so the two form a V-shape. Make it tiltable and connect it to the top lid. When you close the top lid, the V tilts right and the beans on the mesh are kipped into the reservoir.

    When the user pours water in, it could be routed toward his/her general just below the waist area. Only a few times would this happen before the other users in the office would figure it out.

    IMHO, this. If there’s a chance of confusion, the first idea shouldn’t be how to avoid confusion between two things, it should be to make the distinction unnecessary. *If* this solution should really prove impossible for technical reasons that cannot be overcome, *then* move to mitigating the confusion.

  • One would imediately ask the question Are Users Stupid? which often isn't the case. The coffee container above the machine could very well be a place to pour water. Why? It's on top of the machine and since gravity still is around water would go into the machine if we used it that way. Second, it's transparent. Nespresso coffee machines use transparent water tank - so there's a chance of confusion here.

    enter image description here

    So how do we store coffee beans in the cupboard? Not in a transparent container, but more often in a tin jar, or in an aluminium jar. Why don't we mimic that instead? Also we could label it with big red text saying NO Water and to further emphasize our meaning place images of coffee beans on the jar to help our users.

    Finally, we could place our coffee bean jar at the bottom of the machine, with tiny holes in the bottom of the jar making the water that is accidentally poured in the jar escape the machine. We'll end up with a little water on the table, but the machine still works if the user makes an error.

    enter image description here

    Conclusion: There are no bulletproof systems that never fail. But we can help users along the way and minimize the posability of damage through visual cues, text, placement and looks. More importantly, make sure the system doesn't get damaged when something unexpected happens.

    Interestingly, thats an indian coffee maker. You put beans on the top container (on the right) put hot water in, put the plunger, and thick coffee comes out the bottom. The device itself solves the problem in question, by making it part of the process ;p

    A transparent tank might work if it's in a form that's really awkward to load up with a liquid. Here's a design: http://i.imgur.com/gfWd5dJ.png that uses a cylinder with a lengthwise hole in it, which is mounted upright and then rotated sideways to feed a hopper. It's only slightly awkward to load up with coffee, because coffee doesn't have the swash that water does.

    13 years later and that Nielsen article is still one of my favorites.

  • First, don't have an open hopper (even with a lid) on top of the machine into which anything can be poured.

    Second, have the beans go into a container that must be removed from the device in order to fill it. The container could be lifted off the top, or slid out from the side. It could even be like a drawer that does not fully detach.

    Third, the container should have holes in it that are large enough that it could not possibly hold water, but small enough not to let the beans pass through.

    Fourth, to address the issue of air circulation affecting the freshness of the beans: when the bean container is attached/inserted back into the machine, the water pass-through holes should end up sealed simply by their positioning relative to the part of the machine where the container is attached/inserted.

  • It seems to me that the biggest problem is that users pour water in the bean hopper because they can't think of where else to pour it and get confused. So, why don't you put two, identical plastic or aluminum cylinders on the top of the machine. Then, emblazon one with a large brown bean, and one with a large blue drop of water. This sends the message that "water goes here, beans go here, not the other way around", and, because they're right next to each other and are clearly labeled, there's no confusion. Also, because they are right on top of the machine, the hoppers and the symbology printed on them become a prominent part of the design, and users are less likely to confuse the two due to inexperience with the machine. Heck, they'll know where to put beans and water after looking at the picture on the box.

    Personally the biggest problem I have with coffee machines is you have to go hunting for one or the other - the location of, say, the water reservoir is quite obvious but the location of the bean hopper is not, or the other way around. Why not make both of them quite obvious and well marked?

    If the coffee machine doesn't need water, still do this, but still put up the sign explaining that no water is to be poured into any receptable of the machine. Then implement some automatic negative reinforcement mechanism for those who just won't read. The "pour the water back on them" mentioned above sounds good, but I have heard that electrical shocks work great on more intelligent mammals (lab mice), so maybe they would also work on dumb users who refuse to read signs.

    @JanSchejbal Pouring water back on the person (or electric shocks) constitutes positive punishment (positive: adding something; punishment: to reduce the frequency of a behavior), not negative reinforcement (negative: removing something; reinforcement: to increase the frequency of a behavior). Negative reinforcement means you remove something (unpleasant) in response to a desired behavior, in order to increase the frequency of the desired behavior. Now, if the machine continually gave electric shocks *until* water and beans each were poured into the proper receptable, that would be neg reinf.

    I think @ratchetfreak's idea of a dummy water container (whether sealed, filled with lucite, or simply open but not leading anywhere into the machine) is probably the best way to show users that you don't need to put water in because there already is water. Maybe even have it so there is a normal water container that the pipe runs into, and the same machine can be used with or without a plumbing hookup.

  • enter image description here

    One idea is to use an upside down cartridge with a one-way valve. To refill the coffee beans, the user would remove the cartridge, unscrew the valve cap, and fill the beans into the cartridge. The one-way valve should have obvious holes so that it can hold coffee beans, but will not hold water or pre-ground beans. If the user, through some silly error, pours water into the cartridge, the valve would leak the water when they flip the cartridge upside down, hinting them that they're doing something wrong. The machine would have some simple mechanism to open the one-way valve to dispense the beans.

    Additional hints could be added by using a coffee-colored plastic for cartridge, decorating the cartridge with image of beans, and some written text would also help remind them what the cartridge is for.

    Water could go in the through a water pipe.

    too much work to refill beans IMO

    A coffee machine at a previous office worked similar. Only it was even simpler. The one way valve was just a simple plastic slider that would the user would manually operate. You'd close it after filling, and re-open it after putting the container back on top of the machine so the beans would fall down.

  • Could it be an option to make the water connection plainly visible? At the moment, it seems to be hidden behind the machine. That looks nice and clean of course, but what if you would make it very, very obvious that there is already water connected to the machine by moving the connection to the mains to a visible place, and perhaps by showing a transparent pipe running through the machine that is filled with the water to which it is connected?

    To expand this idea, help users understand how the machine works by adding visibility for the entire process: transparent internal water tank (i.e. what's filled from the mains & heated) visible up top, beans on the other side clearly emptying into the grinder & then brew chamber.

  • Don't do anything, let it break and leave it a few weeks before fixing it. During this time, when ever anybody asks why it's not working, just explain that some idiot has broken the machine, by "adding water where the beans go, don't they know it is plumbed in and gets water by itself." Word will soon get around, and everyone will tell new employee's how to fill it.

    The need to educate users means something is not right with the UI. If a coffee machine breaks every time it encounters an uninitiated user group, it is not going to be a popular coffee machine. And rightfully so, I might add.

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Content dated before 7/24/2021 11:53 AM