Have you ever felt like you just bought some lettuce and it’s already gone bad, turning soggy and gross? Or what about that milk — how can it already be past its expiration date? Buying food and then throwing it out before you eat it because it’s gone bad is a common problem for people — in the United States, it’s estimated that people throw out up to 40% of the food they get. What a waste, literally! Not only is that food filling up landfills, accounting for some 31 million tons of waste each year, but it costs people a lot of money too. Each month, it’s about $33 per person wasted, adding up to about $400 for a person in a year.

For this Instructable, I decided to answer the following question: Which foods are thrown out most frequently in my household, and how much money is it costing me? In other words, if I bought those foods in smaller amounts (because I’m not eating them before they go bad), how much money would I save? My hypothesis was that the foods we’re throwing out the most are vegetables (especially lettuce) because I feel like I throw them out a lot, but I don’t think it adds up to that much money — maybe $10 for our household in a month.

A little background about my household: It includes two adults who compost, have chickens, and have a vegetable garden. This basically means that none of our food is actually ever thrown in the trash — any bits that are still good go to the chickens, and everything else goes into the compost. Additionally, we get some food from our vegetable garden (although when I did this investigation in the early spring, the garden wasn’t producing much yet), and doing this Instructable is good to help you know what you should plant in the garden (i.e., what you’ll be able to eat before it goes bad), and what you shouldn’t plant or should plant less of in the future.

Step 1: The Testing Procedure

Data Collected

I created a spreadsheet to keep track of all of the perishable food we got over time. I printed out the spreadsheet and stuck it on the refrigerator so it was easy to fill out when we put away new food. This included foods from the grocery store, our garden, and leftovers (but because of time restraints, I didn’t include foods that didn’t expire for months). For each food, I kept track of the following:

  • Food name
  • Quantity (whatever was a convenient description, such as by the container, ounces, number, etc.)
  • Food cost. I didn’t fill this out originally, but later found this out and filled it in for the foods that were thrown out so I could figure out how much money was lost. I’d recommend filling it out while you collect the other data since you’ll have the receipts handy.
  • Date purchased
  • Expiration date. This was either the listed expiration date (if given) or my anticipated expiration date (for example, I typically expect lettuce to last one week).
  • Amount consumed. This was filled out when we ate all of the food, or when we had to throw some out. If not all of the food was eaten, I found it was easiest to fill this out as a percentage, estimating what percentage was eaten.
  • Amount tossed. This was filled out either when we ate all of the food (and wrote down “0” for the amount tossed), or when we had to throw some out.
  • Date tossed. This was filled out either when we ate all of the food or when we threw some/all of it out.

You can see a picture in this step of some of the data I actually collected. In this step I’ve also included a blank, revised spreadsheet (as a PDF and Excel spreadsheet) so you could use it to do your own investigation!

Determining Whether Food has gone “Bad”

This was usually done by visual inspection — see the pictures for examples. If a food item had an expiration date, such as milk, and it was past its expiration date, I still “tested” it (by visual inspection, smell, or taste) to see if it had actually gone bad or not. Use this method with caution :)

Testing Time Period

I did this investigation for a total of 48 days (from March 3, 2014, to April 19, 2014). I analyzed the data for foods that were obtained during this time period and either completely consumed or thrown out. (Foods that were obtained but not yet completely eaten/tossed weren’t counted in the data analysis.) It’d be great to do this investigation for a longer amount of time, especially since I’m sure there will be seasonal variation as vegetables in the garden are ready to harvest, but I was restricted by time restraints.

<p>Cool graphic!!</p>
<p>Thanks, chipper35! And thanks for checking out my 'ible!</p>
<p>WOW! That's a lot of time and calculations you did for us! Just thinking about it makes my head spin. I've been wanting to keep better track of what our family throws away (mostly perishables, like you) too, and you've very kindly taken all of the hard work out of it for me! Thanks for the spread sheets as well. Fantastic instructable!</p>
<p>Thanks so much for your positive comments, bifaerie79! I really appreciate it. It was a bit of work, but I think it was worth it. </p><p>Since we often just weren't eating food before it expired, I think we'll keep a simplified version on the refrigerator at all times that just shows what's in there, and its expiration date (based on our experience, as shown in this Instructable). It's easier to eat the food before it goes back if you can quickly see that information and are just more aware of it, I think -- better for planning meals.</p>
<p>Great job on this. We rarely toss food in our two person household unless I get sick and cannot prepare the fresh produce I purchased to use that week. We had to live on little for a few years and discovered as you have that things last longer than we think sometimes. <br><br>I had never heard of the butter trick either so thanks to Rick for the great tip! </p>
<p>1 don't buy more perishables than you need for the next few days.</p><p>2. Ignore use by dates - If it looks Ok - Smells Ok then more then likely it is OK.</p><p>3. Use basic preservation techniques. Fridge 4 deg C 39 deg F</p><p>Freezer -18 deg C 0 F</p><p>Food that has been cooked can be refrozen to use later</p><p>Store salad and fresh veg in plastic ware containers to minimise water loss.</p><p>Coat foods that brown - eg avacado with lemon juice this will stop the browning.</p><p>Don't keep bananas with other fruit - they give off ethylene gas which ripens fruit quickly.</p><p>Coat cheese with a layer of butter or spread to stop it growing mould. Just wipe it all over with your finger.</p><p>Things that are pickled or very high in sugar will not go bad as bacteria cannot grow - HOWEVER modern products often have reduced sugar and other preservatives which don't work as well. Answer pickle, can your own food when it is cheap and plenty full.</p>
<p>Thanks for the tips, rickharris -- I agree (though I'd never heard of the cheese and butter trick -- I'll have to try that!). We also do a lot of our own pickling/preserving/canning from our garden -- we've still got tons of cans of pickles, pickled beets, and apple butter from a year ago. For tip #1 though, I think it can be hard for people to accurately estimate just how many perishables they need in, for example, a given week -- that's why doing something like this Instructable can be useful because it gives you an idea of what you're actually eating before it goes bad. Thanks for checking out the Instructable! </p>
What's mahi mahi
<p>It's a type of fish. Although it was cooked, I don't like to keep fish longer than three days. Thanks for checking out my Instructable!</p>

About This Instructable


127 favorites


Bio: I am a scientist, professional science writer, and science educator. I'm also author of the Biology Bytes books: http://www.biology-bytes.com/book/.
More by Teisha: Automate Your Shopping! Mini Paper Mache Light-Up Christmas Tree Minecraft Snow Golem Ornament
Add instructable to: