Low Technology Institute

Calories Grown in Foodmageddon

View of the greenhouse at the begin of July.

This last year, we challenged ourselves to grow our own food, as if fossil fuels disappeared. Starting in February, we simulated collapsing transportation and agricultural infrastructure by buying less and less at the grocery store: first we lost produce, then frozen, and by the end, even shelf-stable foods. In August, we were essentially cut off from all external sources of food.

We calculated that we’d need almost three million calories to support ourselves:

We are a family of two and a half people, plus a dog and seven chickens. Two adults eating 2,000 calories a day need 1.46 million calories in a year (2 × 2,000 × 365). A one-year-olds need 1,000 calories a day, so 356,000 calories for the year. We’ll need that again for our dog. Each chicken needs about 230 calories per day, so we’re looking at 578,650 calories (7 × 230 × 365). That puts us well over two million calories (closer to 2.8 million total).

Blog post from February 24, 2020

We’re actually nine chickens, so that total can be revised to 2.93 million calories.

Grown, Gathered, and Gleaned Calories

If we were forced to feed ourselves, how much could we grow, gather, and glean from near our house without fossil fuels? It turns out, one person was able to generate over a million calories. It is reasonable to assume that with another person or even more work, that could have been doubled.

In the garden, we grew many vegetables and greens to eat all summer and fall, but we also had a mind for storage, growing winter squash, potatoes, and others. The biggest source of calories were potatoes, bringing in almost 70,000 calories. Although our beans had a rough go of it, we still got over 7,000 calories of them. Sweet potatoes, tomatoes, carrots, cucumbers, dried peas, kale, kohlrabi, and onion also brought in from 7,000 to 2,000 calories (in descending order). Obviously the purpose of many of these calories is to spice up the starches and other bland calorie powerhouses. In total, the garden gave us about 125,347 calories. See the full amount of grown foods in the table at the end of this section.

We also gathered about an equal number of calories from our surroundings: 118,591. This included apples, which we dried, sauced, and turned into juice and cider (see the video here). We also collected quarts of raspberries and strawberries from our plants. We have a prolific black walnut tree and processed pounds of them, with three or four times more uncounted and unprocessed in our basement. About a third of those calories came last spring, when we made a few gallons of maple syrup (here’s that video).

There’s a reason grains are the staff of civilization: they hold thousands of calories in a small, shelf-stable commodity. We harvested a tenth of an acre of wheat and got about eight bushels, accounting for a whopping 604,440 calories (see the video here). Our corn did not do well and we only got a half a bushel, but even that gave us 43,775 calories. Our oats had some issues and didn’t do well. Same with our flax, whose seeds had gotten damaged. It is a shame, because the year before both of these crops did quite well. We missed the extra hundreds of thousands of calories these would have provided, but not all would run perfectly in a collapsing world.

Our last category of self-created calories come from animals. We discuss the ethics of meat elsewhere, but they do provide a lot of calories with minimal effort. Venison, for example, netted us a month’s worth of calories for three people for maybe a week’s worth of work for one. We butchered three chickens, providing more protein and 9,852 calories. The remaining chickens gave us an additional 28,080 calories from their eggs throughout the year. Finally, our bees provided another 55,280 calories from a bit over three gallons of honey.

Our grand total, then, for one person to create in a year was 1,071,165 calories. If this was really happening and my life depended on it, I probably would have taken another deer or two, and more aggressively sought out unharvested corn and soy as a calorie back-up store. Plus, with the collapse of fossil fuels, my partner (and neighbors) would have been also active in gathering and growing provisions, bumping up the total calories even more.

External Calories

Although a sudden collapse of fossil fuels would precipitate major changes, they’d take a little time to come into play. That allowed us to stockpile some foods. Before August, we purchased vegetable and olive oil, sugar, flour, oats, legumes, peanut butter, milk (to make cheese), and butter, because we knew these would be hard to make on our own. This totaled 685,943 calories.

We also purchased food for our animals: dog food and chicken food (287,100 and 320,000 calories, respectively). Additionally we bought sunflower seeds and feed peanuts (another 275,720 calories). We also “gathered” four bushels of field corn for the chickens (392,224 calories). If fossil fuels collapsed in the late spring, fields would still be planted, so we would have been able to gather as much field corn as we wanted from the fields surrounding our village.

These external calories were in the project conception, as people would hoard food during a catastrophe. This was made all the more realistic because the COVID-19 pandemic caused us to be careful in our purchases for real. Luckily, people were buying for short-term hoarding, not with a year of food independence in mind. We were able to easily buy cooking oil, sugar, butter, peanut butter, milk, and oats in large quantities. The difficulty was finding flour, but we only needed enough to get us through mid-summer when our own wheat would come in.

We also had what we called “extra-curricular” calories. We’re just regular people and in order to maintain our sanity over the year, we did purchase some extras to keep us happy. We would occasionally buy tortilla chips, chocolate, tea, cookies, and other treats. We did not buy any staples during this time. We also gave away some of our own generated calories. For example, we’d bring pickles when visiting family and hosted our niece for almost three months. We also received a few boxes of random food as COVID-19 support. In all, the treats and other incoming calories were almost exactly balanced out by the extra foods given out. Only 13,619 extra calories were added to our larder, meaning we should delete three days from our total.

How Much Longer Could We Go?

As of mid-February, we have about 498,944 calories left in the larder. From August, when we were completely cut off, to February (six months) we used 1.26 million calories (= 1.07 million + 0.69 million – 0.50 million). We only start making serious calories from the garden by mid-summer at the earliest, so at that “burn rate (0.21 million calories per month), we’d get in trouble by the end of April. In agricultural societies, the spring is known as the hungry time for a reason: you’re working hard to get the crops in but running out of last-year’s food while you do it. If this were a real crisis, as I said above, we’d have had two people working on storing food and would have at least taken another deer. We would make it, but next year would be extremely difficult, as our oil would run out by the end of spring at the latest.

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