What are the ideal cupboard conditions in which to hygienically store cups?

July 7, 2011 5:53 AM

What are the ideal cupboard conditions in which to hygienically store cups?

Some factors to consider:

• The initial cleanliness of the cupboard
• The particulate retention of the platform material
• The presence or absence of a textured shelf liner
• The presence or absence of cupboard doors
• The amount of time the cup is stored before use
• The amount of moisture still on the cup when it is put away
• The arrangement of cups (stacks or singles; rim-side up or rim-side down)
• The environmental effects of temperature, humidity, and open air on bacteria cultures
• The pathways of contamination (any part of the cup that contacts the drinker or the liquid, e.g. a lip-sized portion of the rim and the interior; anything that touches the cup)

As you can see, the permutations are endless, so it is useful to fix or ignore some variables when considering the problem. Take, for example, a comparison of platform cleanliness, cup arrangement, and time stored (ignoring all but three variables). You might note that if you placed a single cup on a layer of dust in a cupboard with the rim-side down for one minute and then drank out of it, you would ingest more dust than if you had placed the cup rim-side up for the same amount of time (modifying only one of the three variables). Keep in mind that some of these conditions aren't worth consideration singly (a clean cupboard is obviously more ideal than a dirty cupboard), and take relevance only when paired (if a cupboard's surface was unavoidably dirty, a rim-side up approach might be better). So while I am reaching for an "ideal," we are dealing with real-world conditions and it would make sense to imagine an "average household" for the purpose of this question.


I have had this argument at length with multiple people. Most households have an idiosyncratic Correct Way which usually boils down to the rim-side-up-or-down dichotomy. While this is the most common form of the problem, I found the underlying precepts to be wide-ranging and marginalized by the debate over the rims. Many of those precepts are listed above.

So, what combination of these conditions is hygienically ideal?

posted by troll to Home & Garden (23 answers total)

I use those meshy rubberized fabric liners for the bottom of cupboards, which can be laundered in cold water, and then store everything upside down in stacks.

I have not yet died of the plague so I assume that this is a good storage solution.
posted by elizardbits at 6:12 AM on July 7, 2011

elizardbits - all that tells you is it's a "good enough" storage solution, or perhaps a "not demonstrably bad" storage solution...

So while I am reaching for an "ideal," we are dealing with real-world conditions

under real-world conditions, where humans have spent millennia under evolutionary pressure to be able to deal with non-sterile conditions, it doesn't matter how you store your cups and glasses because they won't make you sick...
posted by russm at 6:23 AM on July 7, 2011 [11 favorites]

IANAmicrobiologist or specialist in how household dust might make you sick. I have worked in various food service jobs.

Assuming the cupboard is reasonably clean to begin with, has a door, and the cups are clean when you put them in there, then there's unlikely to be any difference in whether they're stored upside-down or not, single layer or stacked. (Data point: ours go in a cupboard with a door, and because of the ability of cups to multiply when you're not looking, we have enough that they are upside-down so they stack easily.) The drier they are, the better.

Kitchen sanitation is about risk mitigation. Unless you have a condition that severely compromises your immune system, the likelihood of you getting sick from dust on a cup rim is miniscule. You're more likely to get something nasty from an improperly cleaned cutting board, or that bag of organic baby spinach in your crisper.
posted by rtha at 6:34 AM on July 7, 2011

I think that the most dangerous thing you could do with a glass would be to drink from it right after another person has - this would mean you're exposed to bacteria and viruses they may have left on the glass. Dust from the cupboard may not be great for you, but it's going to be a lot less dangerous than another person's saliva. Therefore I would recommend washing glasses thoroughly with soap and hot water, and then not worrying about how they're aranged in the cupboard.

Sorry, this probably isn't the level of beanplating that you are looking for.
posted by medusa at 6:35 AM on July 7, 2011

Best answer: Abstract:
Wow, microbiologist here, perhaps I can help.

Introduction:
The ideal condition would be to wrap the opening in aluminum foil, autoclave under high pressure live steam, and then store in a single layer in a positive pressure cabinet with hard UV-emitting lamp.

Discussion:
Seriously, up or down doesn't make a difference. There might be a little dust in the cabinet. Dust is not a breeding ground for pathogenic bacteria or funguses. Your house is already a snowglobe of dust in which you already survive everyday. You can argue surface area for stuff to fall in on the bottom of the cup versus the rim touching the bottom of the cabinet, but your real route for bacterial transfer is still via unclean human hands touching the cup. Your first four points are really concerned with dust, which is not cause for concern. Dust doesn't look nice, but it's not a hygienic problem.

Time in storage is a non-issue. Unless your cup is caked in something that bacteria or fungi enjoy eating, nothing new will grow on your cup over time.

Moisture does make life happy. Assuming the cup is about as wet as they come out of my washer, it breaks down two ways: The cup is wet and used quickly, thus there's little time for anything to grow (it was clean coming out of your washer anyways). The cup is wet and isn't used for a while, so the water evaporates. Either way, your total exposure is low.

Regarding the environmental effects of temperature, humidity, and open air on bacterial cultures. Your cabinet is a poor place to grow pathogenic bacteria. It's not warm enough, it's too dry, and doesn't offer a lot of food sources.

Moreover, your exposure to dust, bacteria, and funguses from cup storage is entirely insignificant as long as you continue to own and use plates.

Conclusion:
Any cup storage method in a modern cabinet is fine. You're a big, healthy, hand-washing vertebrate with a robust immune-system. I put mine rim-up in a single layer.
posted by Mercaptan at 6:37 AM on July 7, 2011 [203 favorites]

If the humidity is high enough, like in some Southeast Asian countries, will a wet cup just stay wet?
posted by smackfu at 6:39 AM on July 7, 2011

Best answer: If you're trying to win an argument I don't think you'll get very far because people cling steadfastly to their "idiosyncratic best methods" no matter how many facts you throw at them (you can't reason them out of a position they didn't reason themselves into in the first place). If you want to test your parameters you can set up an experiment* but you'll need a way to grow bacterial cultures from your test swabs and you probably don't have the facilities for making sterile agar plates (know any kids in search of a science fair project? this could actually be a pretty amusing thing to look at).

Here's my opinion about the whole thing: you want to minimize microbial growth on your dishes. However, this has already been engineered into the design of your kitchen cabinets and, more importantly, the materials used to make the dishes. They are nonporous and smooth, so food particles don't hang around after washing and they dry out quickly. The doors on your cabinets keep flying splatters of food from landing on your clean stuff and providing a home for microbes. The smooth nonporous surfaces in the rest of your kitchen are easy to clean and keep microbial growth to a minimum.

Because of this "invisible" background engineering, you have a lot of leeway in how your store your dishes. If you used unglazed clay dishes or lived in a hut with dirt floors and open shelves you'd have to be more careful, but you benefit from all the work that's gone into developing sanitary kitchens over the centuries. So you won't really see much difference in hygiene based on the factors you've listed because hazards have already been mitigated at the back-end.

*You have a bunch of factors that interact so you'll want to do a factorial experiment. That's a lot of work.
posted by Quietgal at 6:49 AM on July 7, 2011 [4 favorites]

My lab would just swab everything down with 70% 2-propanol, though you might consider ethanol--it's more versatile in a kitchen setting. If the item's sterility was really critical, we would also light it on fire.
posted by pullayup at 6:50 AM on July 7, 2011 [6 favorites]

Cup hooks are your friends.
posted by scruss at 6:56 AM on July 7, 2011 [1 favorite]

My best friend in Junior High insisted they must go face-down so that roaches and spiders couldn't crawl in them. (It was Texas, these things were inevitable.) I pointed out that face-down meant putting them down where one of those things might have previously traveled. She solved the problem by washing every glass again immediately before use.

You didn't include "wildlife" as one of your three factors, but I've never put a cup away since that day without a moment of hesitation, so I thought I'd share.
posted by Lyn Never at 7:07 AM on July 7, 2011

In my house (short-term rental) the cupboards are filthy so cups go rim up. It's not really a microbiological issue: I just don't like tasting dust.

Troll, are you looking for a more theoretical (less practical) discussion? Because I agree that the variables interact. For example, if you have doorless cupboards and infrequently-used glassware, it only makes sense to store cups rim down to avoid them gathering dust. This of course means you would have to have clean cabinets. Also, stacking would not be amiss here.

(As an aside: your name implies that you may have the necessary diplomacy to resolve the issue with your "multiple people", but God help you, my son, if they're your housemates.)
posted by inkisbetter at 7:40 AM on July 7, 2011 [1 favorite]

I used to volunteer at a transitional housing facility for people with AIDS. They put their dishes away wet. Considering that these were severely immuno-compromised people, it must not make much of a difference how dishes are stored.
posted by desjardins at 8:03 AM on July 7, 2011

Are you aware of the Hygiene Hypothesis? In essence, constant exposure to germs is good for you.
posted by Chocolate Pickle at 8:07 AM on July 7, 2011

Not exactly, Chocolate Pickle. The hygiene hypothesis states that "lack of early childhood exposure to ... microorganisms ... increases susceptibility to allergic diseases by suppressing natural development of the immune system." (Wikipedia, emphasis mine.)
posted by inkisbetter at 8:50 AM on July 7, 2011

Lyn Never: This is solved by stacking (rim down). That way only the bottommost glass needs to be washed twice.

We store disposable plastic cups in our basement (an unsanitary environment if there ever was one). They're in plastic bags, but sometimes the top of the bag is open. Rim down definitely results in less dust in the bottom (top) cup. Even so, it often becomes a sacrificial "art project or other non-drinking use" cup.
posted by anaelith at 9:39 AM on July 7, 2011

My grandmother grew up in the Saskatchewan dustbowl. Her glasses are stored upside-down to this day. She is the only person I know who does that.
posted by Sys Rq at 1:41 PM on July 7, 2011

Best answer: I am also a microbiologist and store my cups however they end up in the cabinet without a thought. However I did store them upside down when I was growing up to help deter my millions of cockroach housemates/neighbors. Even then, from a public health standpoint none of it matters, I just didn't want to see roaches in my glasses. Seriously none of it matters. The dust in your house is likely mostly you (or rather your dead skin cells) anyway, and if not, it would be soil which is also for the most completely harmless.

If what you are interested in is sterility, which is itself unhealthy*, then you don't really need an autoclave. I was trained in a poor student run lab at a small university with a sporadically functioning steam system that ran our autoclave and I homebrew with sensitive cultures, I can tell you, you don't need one. All you need is an oven for sterile glass, ceramic, steel, or aluminum utensils, cups or whatever. Just put some foil over it, and leave it in your oven at 450°F for 12 supervised hours and everything will be very very dead. It is still the best way to sterilize glass pippetts.

*It is very easy to neglect one of your most essential organs with 10 times as many cells as the rest of your body combined that produces just about all of the compounds that you need which are weird or exotic in any way.
posted by Blasdelb at 2:26 PM on July 7, 2011 [5 favorites]

Mod note: your jokes removed. fyi.
posted by jessamyn (staff) at 5:28 PM on July 7, 2011 [1 favorite]

Given the above-mentioned point that the biggest problem for actual sanitation is human hands touching the bits of the cup you will drink from, rim-down is best. That way you are forced to pick the glass up by the bottom, which is not the bit your mouth or your guest's mouth will touch. If you store the glasses rim-up, you might pick the glass up by the rim, close to the rim, or with fingers inside the glass, transferring more hand-germs to the drinking-bit of the glass.

That said, I totally do not do this in my house. Glasses go in the cupboard whichever way I happen to be holding them at the time.
posted by lollusc at 10:36 PM on July 7, 2011

Moreover, your exposure to dust, bacteria, and funguses from cup storage is entirely insignificant as long as you continue to own and use plates.

Okay... now I really want to know why plates are scary.
posted by L'Estrange Fruit at 8:38 PM on July 8, 2011

Well as you know all plates are made from 75% flesh eating bacteria.

Okay okay, I just meant that plates have a much larger surface area that dust, fungi, and bacteria could land on. But people tend to stack them, so it's not a big deal either.
posted by Mercaptan at 9:13 PM on July 8, 2011 [1 favorite]

Put a high-intensity UV light in your cupboard and wash everything before, during, and after use.
posted by blue_beetle at 2:17 PM on July 26, 2011

"Put a high-intensity UV light in your cupboard and wash everything before, during, and after use."

The kinds of bulbs that would actually produce a meaningful affect are so dramatically inappropriate for a home environment that the idea of installing something like this is beyond absurd. Air works as a pretty decent insulator against UV damage for bacteria, not so much for you. What stuff there might be on your glasses will out survive you in the presence of UV, and you don't really want to kill it anyway.
posted by Blasdelb at 11:08 AM on January 29, 2012