The Natural Resources Defense Council has issued a report (PDF) about the amount of food that Americans waste every year. Now, not all of it is wasted in the home; a good deal is wasted all along the line, according to the report, from the field to the factory, the distribution chain, and the end points of restaurants and our dining tables.
There's not much, if anything, you can do about how much food is lost before you put your groceries away, I don't think. One should probably assume that the invisible hand will prevent farmers, middlemen, restaurateurs, and grocers from wasting too much food in the interest of maximizing their profits. I guess the invisible hand has done the math and figures that there's an acceptable amount of food that it can allow to slip through its fingers to keep its profits up. That is, at some point it must cost more to save or continue handling some amount of food than it costs to lose or dispose of it.
But here at the homestead, it's essentially 100% unacceptable to waste food, where "to waste food" means to throw it out or let it go bad before I use it. It costs almost zero dollars for me to lose or dispose of food. My trash collection is free, because it's a no-cost-added service from the City of Philadelphia, paid through my taxes. (I don't compost because I don't garden, for architectural reasons.) Now, how much does it cost me to put food down my sink disposal? I blush to confess I've never done that math. I use some amount of water, some amount of heating gas if the water going down is warm, and some amount of electricity. Outside of the cost of the food itself, if I run the disposal for 10 seconds, I will ballpark and say it costs me 2 cents. Some days I run it twice, some days I don't run it; so let's say that I run it once per day, and thus it costs me $7.30 per year to run my disposal. I'm fine with this cost, and here's why. The way I run my disposal is to cram the waste and food trimmings into the drain before I wash the dishes. Then I run the disposal as I drain the sink after doing the dishes. Not only does this get the garbage down without splashing odors into the kitchen, but it also serves to really flush out the disposal and maintain it in a clean condition. In fact, I run the disposal when I drain the sink whether I have garbage down in it or not, for that cleaning effect. And I'm OK with paying $7.30 per year to keep my kitchen smelling a little better than kitchens I've lived in that didn't have sink disposal.
That figure, though, doesn't include the food I'm throwing into the disposal. The most important thing for me to remember here is that the Rowhouse Livin' invisible hand works differently from that of the farmers, middlemen, restaurateurs, and grocers mentioned above. For me, when I don't use food that I buy, it's squarely a problem of throwing money away.
What to do? The Unclutterer blog suggests buying a dry-erase marker notetaking solution, but I'd rather do something that doesn't require whipping out my credit card. Instead, I visualize actually throwing money away. Two pounds of potatoes have turned irretrievably green and sprouted in a back corner of the kitchen? That's two crisp dollar bills floating out the door and into the sanitation truck. A can of beans went all bulgey after I missed it during my last emergency food rotation check-in? That dollar makes a loud "thump" when it lands on the bottom of the kitchen garbage can. Kiwi fruit were 3 for $2 but I ate only two of them before the last one shriveled and got moldy? That's two quarters, a dime, a nickel, and two pennies clinking around the disposal blades with the kiwi's core.
It doesn't seem like much; but if you saw 67 cents in a little stack on the sidewalk, wouldn't you pick it up? After all, you could buy a kiwi fruit with it.