To reuse or not to reuse, that is the question.
January 14, 2011 1:16 PM Subscribe
How much hot water can I use washing a re-usable cup before it's a net environmental loss?
Every day, I get a super-dense chocolate drink in my plastic re-usable cup. The drink is very very thick; it turns entirely solid, an almost mousse like texture, when cold. This means cleaning out the cup isn't a simple rinse out operation. And since I have one of these every day, I can't just wait to clean it in the dishwasher, I don't have a full load's worth of dishes more than once a week.
I am starting to wonder, given the amount of water it takes to clean the cup, if getting a fresh disposable cup each time would be environmentally 'better'.
Every day, I get a super-dense chocolate drink in my plastic re-usable cup. The drink is very very thick; it turns entirely solid, an almost mousse like texture, when cold. This means cleaning out the cup isn't a simple rinse out operation. And since I have one of these every day, I can't just wait to clean it in the dishwasher, I don't have a full load's worth of dishes more than once a week.
I am starting to wonder, given the amount of water it takes to clean the cup, if getting a fresh disposable cup each time would be environmentally 'better'.
Best answer: It depends on how often you use your cup, and what kind of disposable you would be using. There's the initial energy cost for making the cup then the incremental costs for cleaning it each time. There's a short discussion of that here (pdf), but the bottom line is that reusable is better than paper, but styrofoam cups are right on the balance point with reuse. Keep in mind too that this study assumed an efficient industrial dishwasher system. Hand washing could be several times more expensive.
So, you're better than a paper cup after only a couple of dozen uses, but it takes hundreds or reuses for a non-disposable cup to be better than foam. Also, a disposable plastic cup would presumably be a bit higher than the foam one. Styrofoam is about the cheapest plastic to make there is.
posted by bonehead at 1:27 PM on January 14, 2011 [1 favorite]
So, you're better than a paper cup after only a couple of dozen uses, but it takes hundreds or reuses for a non-disposable cup to be better than foam. Also, a disposable plastic cup would presumably be a bit higher than the foam one. Styrofoam is about the cheapest plastic to make there is.
posted by bonehead at 1:27 PM on January 14, 2011 [1 favorite]
It's not one disposable cup vs. many washings with hot water; it's one disposable cup vs. one washing with hot water. Each time you drink your chocolate drink, your choose between washing your cup or getting a new disposable one.
So the reusable cup is almost certainly better: it doesn't take that much energy to pump the water or heat it, but it takes quite a bit of energy (and water) to cut down a tree, ship it to the paper factory, make it into paper, make the paper (and other materials) into a cup, package and ship the cup, and recycle it after you throw it away.
posted by Chicken Boolean at 1:28 PM on January 14, 2011 [1 favorite]
So the reusable cup is almost certainly better: it doesn't take that much energy to pump the water or heat it, but it takes quite a bit of energy (and water) to cut down a tree, ship it to the paper factory, make it into paper, make the paper (and other materials) into a cup, package and ship the cup, and recycle it after you throw it away.
posted by Chicken Boolean at 1:28 PM on January 14, 2011 [1 favorite]
Don't forget that this isn't a simple energy use comparison. By using a disposable cup every day, you're also contributing to a serious waste problem -- where's that cup going to go after you throw it out?
In my opinion, it would take a hell of a lot of hot water to overcome that. Go reusable!
posted by auto-correct at 1:28 PM on January 14, 2011 [1 favorite]
In my opinion, it would take a hell of a lot of hot water to overcome that. Go reusable!
posted by auto-correct at 1:28 PM on January 14, 2011 [1 favorite]
I might be missing a point here.. but..
Why not buy five re-usable cups? Wash whatever ones are dirty in the dishwasher when you go to wash dishes.
Unless your reusable cups are expensive, you're saving both time and effort and water and paper.
posted by royalsong at 1:37 PM on January 14, 2011 [1 favorite]
Why not buy five re-usable cups? Wash whatever ones are dirty in the dishwasher when you go to wash dishes.
Unless your reusable cups are expensive, you're saving both time and effort and water and paper.
posted by royalsong at 1:37 PM on January 14, 2011 [1 favorite]
If you are willing to expend this amount of energy figuring it out, could you rinse the cup out prior to it getting cold and solidifying? That way you dislodge the bulk of the sludge without having to resort to using hot water.
posted by edgeways at 1:40 PM on January 14, 2011 [1 favorite]
posted by edgeways at 1:40 PM on January 14, 2011 [1 favorite]
Can you soak the cup to loosen all the chocolate, then use a minimal amount of water to wash and rinse?
posted by padraigin at 1:47 PM on January 14, 2011 [4 favorites]
posted by padraigin at 1:47 PM on January 14, 2011 [4 favorites]
Best answer: With all due respect, Chicken Boolean, you have to include the energy/water cost of the non-disposable cup too. It's a sunk cost by the time it gets to the person using the cup, sure, but that doesn't mean that it hasn't been incurred and should not be counted. The marginal washing cost is only one part of the cup lifecycle.
Disposal is absolutely important too, as are things like environmental burdens of production (like CO2 from the manufacturing plant) and waste degradation products (like endocrine disruptors in the plasticizers). The study of all of these together is formally known as Life Cycle Assessment (or analysis). Here's the thought process that one goes through to set up these multi-factor analyses.
The disposable cup one is a favourite choice for study because the issues are relatively simple. Here's a typical example for resuable vs disposable cups in a stadium setting (pdf). The resuables are better in that case as well, but the differences are not as big as you might think.
posted by bonehead at 1:49 PM on January 14, 2011
Disposal is absolutely important too, as are things like environmental burdens of production (like CO2 from the manufacturing plant) and waste degradation products (like endocrine disruptors in the plasticizers). The study of all of these together is formally known as Life Cycle Assessment (or analysis). Here's the thought process that one goes through to set up these multi-factor analyses.
The disposable cup one is a favourite choice for study because the issues are relatively simple. Here's a typical example for resuable vs disposable cups in a stadium setting (pdf). The resuables are better in that case as well, but the differences are not as big as you might think.
posted by bonehead at 1:49 PM on January 14, 2011
By the assumptions in your question, I might be better getting disposable pots and pans. To follow on to bonehead and others, it takes energy and water to make any cup, transport it to you, and dispose of it. You'd have to be washing your cup with an awful lot of hot water to make it less worthwhile (environmentally) than a disposable.
That said, I'd be scraping the cup clean with a spoon and eating it, then letting it soak in water for a bit before washing it - that should cut down on your water use.
posted by ldthomps at 1:54 PM on January 14, 2011
That said, I'd be scraping the cup clean with a spoon and eating it, then letting it soak in water for a bit before washing it - that should cut down on your water use.
posted by ldthomps at 1:54 PM on January 14, 2011
bonehead: you have to include the energy/water cost of the non-disposable cup too
He already has the cup, so it's a sunk cost. Whether he should buy a reusable cup if he didn't already have one is a different question (whose answer depends on the initial energy cost as well how many times he'd use it).
More practically, I think padraigin has the right idea.
posted by Chicken Boolean at 1:58 PM on January 14, 2011
He already has the cup, so it's a sunk cost. Whether he should buy a reusable cup if he didn't already have one is a different question (whose answer depends on the initial energy cost as well how many times he'd use it).
More practically, I think padraigin has the right idea.
posted by Chicken Boolean at 1:58 PM on January 14, 2011
+1 for having a set of cups and batch-washing them on the weekend.
posted by Hairy Lobster at 2:16 PM on January 14, 2011
posted by Hairy Lobster at 2:16 PM on January 14, 2011
Response by poster: Why not buy five re-usable cups?
I worry at how nasty the cups would get waiting their turn, and if letting the chocolate dry out onto the cups would just make cleanup harder and thus more water expensive.
Can you soak the cup to loosen all the chocolate, then use a minimal amount of water to wash and rinse?
I fill the cup up with near boiling water prior to cleaning for this reason.
That said, I'd be scraping the cup clean with a spoon and eating it, then letting it soak in water for a bit before washing it - that should cut down on your water use.
Total consumption of the chocolate is my general goal. There are difficulties; I am trying to maximize economic value by purchasing the largest drink size, but spreading the drinking/eating out over two meal periods (buy at night on the way home, have 1/3, fridge the rest, eat as much of the remaining 2/3s the next morning for breakfast at work). If I got the next smaller size down, I'm guaranteed to run out while still hungry.
I'm leaning towards the multiple cups. I would have to carry an empty-clean with me to work each morning alongside the 2/3-full breakfast cup though.
posted by nomisxid at 2:23 PM on January 14, 2011
I worry at how nasty the cups would get waiting their turn, and if letting the chocolate dry out onto the cups would just make cleanup harder and thus more water expensive.
Can you soak the cup to loosen all the chocolate, then use a minimal amount of water to wash and rinse?
I fill the cup up with near boiling water prior to cleaning for this reason.
That said, I'd be scraping the cup clean with a spoon and eating it, then letting it soak in water for a bit before washing it - that should cut down on your water use.
Total consumption of the chocolate is my general goal. There are difficulties; I am trying to maximize economic value by purchasing the largest drink size, but spreading the drinking/eating out over two meal periods (buy at night on the way home, have 1/3, fridge the rest, eat as much of the remaining 2/3s the next morning for breakfast at work). If I got the next smaller size down, I'm guaranteed to run out while still hungry.
I'm leaning towards the multiple cups. I would have to carry an empty-clean with me to work each morning alongside the 2/3-full breakfast cup though.
posted by nomisxid at 2:23 PM on January 14, 2011
Fill the cup up with hot water, and let it soak til it's only warm. Then wash it with lukewarm water. That's as good as it's gonna get.
posted by notsnot at 2:39 PM on January 14, 2011
posted by notsnot at 2:39 PM on January 14, 2011
Fascinating. I had no idea foam was that energy-lean. If I read that one chart right, I have to use a ceramic cup 1000 times before it breaks even with using foam cups?
posted by gjc at 2:41 PM on January 14, 2011
posted by gjc at 2:41 PM on January 14, 2011
Surely you use other dishes during the day? If you are boiling a pot of water for every cup you clean, that's kind of wasteful, but if you take home a dirty cup, fill with hot tap water while you are busy in the kitchen, then wash with other dishes, it will be clean, and not be wasteful. If you let dishes sit with food in them, they get icky, but are fine as soon as they're washed. Food-grade containers + reasonably thorough washing & drying are fine.
posted by theora55 at 2:54 PM on January 14, 2011
posted by theora55 at 2:54 PM on January 14, 2011
Response by poster: Surely you use other dishes during the day?
I don't cook or eat at home most of the time, so my daily dishes consist of the aforementioned cup, one water glass, and one fork for getting wet food out of the can for my kitty.
posted by nomisxid at 3:09 PM on January 14, 2011
I don't cook or eat at home most of the time, so my daily dishes consist of the aforementioned cup, one water glass, and one fork for getting wet food out of the can for my kitty.
posted by nomisxid at 3:09 PM on January 14, 2011
Polystyrene foam is quite lean on the production side, but the disposal story is very bad. Styrene does not breakdown and cannot be recycled at reasonable cost. It's a major component in the ocean garbage gyres because it doesn't photodegrade or get broken down by microbes. So, even though it's low energy cost to produce, it may be one of the least desirable choices because disposal is so hard.
posted by bonehead at 3:09 PM on January 14, 2011
posted by bonehead at 3:09 PM on January 14, 2011
As someone who A) prepares and eats all her meals at home, and B) does not have a dishwasher but has to wash everything by hand: I think you need to add a squirt of dishwashing liquid and let it soak a little bit longer.
The less time you soak it, the hotter the water needs to be in order to work. If you want to wash it five minutes from now, you'll need to pour in near-boiling water. But you could give it a squirt of dishwashing liquid, pour in cold water, let it soak overnight, and it would rinse out the next morning just as easily.
Also, you might try scooping out some of the sludge and throwing it away first. If it's that fatty and sludgy, it probably shouldn't be going down your pipes anyway. (Use your cat food spoon, to save on dishes.)
posted by ErikaB at 5:21 PM on January 14, 2011
The less time you soak it, the hotter the water needs to be in order to work. If you want to wash it five minutes from now, you'll need to pour in near-boiling water. But you could give it a squirt of dishwashing liquid, pour in cold water, let it soak overnight, and it would rinse out the next morning just as easily.
Also, you might try scooping out some of the sludge and throwing it away first. If it's that fatty and sludgy, it probably shouldn't be going down your pipes anyway. (Use your cat food spoon, to save on dishes.)
posted by ErikaB at 5:21 PM on January 14, 2011
This comparison gives ceramic mugs the edge, even including cleaning. But if you wash as ErikaB suggests, and keep the cup for several years, then you're coming out ahead.
posted by harriet vane at 2:50 AM on January 15, 2011 [1 favorite]
posted by harriet vane at 2:50 AM on January 15, 2011 [1 favorite]
I think I understand what you are saying... I use one ceramic cup at my office and rinse it out before using it again. If I didn't do this I would be using 2-4 cups per day X 5 days x 4 weeks = 40-80 cups per month vs 1 mug.
I have been using the same mug for over three years at this point, so that is between 1,440 to 2,880 cups saved.
Mug has the advantage.
posted by darkgroove at 5:08 PM on January 15, 2011
I have been using the same mug for over three years at this point, so that is between 1,440 to 2,880 cups saved.
Mug has the advantage.
posted by darkgroove at 5:08 PM on January 15, 2011
This thread is closed to new comments.
posted by GuyZero at 1:20 PM on January 14, 2011