Tuesday, 11 June 2013

Keeping food

Wherever they lived in the world, people faced the same dilemma: they need food every day of the year, but most foods are only available for a brief season.

Around us, for example, hawthorns bear shoots for a few weeks in spring, sorrel emerges in the summer, and berries appear for a few weeks in autumn – but none of those provides a great deal of nutrition, and a diet of just a few species of plants in any week would grow quite monotonous. Then, of course, there are long months of winter where little grows, and if you get a year like we had in 2012, you get the equivalent of eighteen months of winter. And Ireland, of course, has one of the most temperate of climates; most regions of the world dry up, freeze, bake, swelter or flood for long stretches of the year.

If you are like many animals, the lean times are simply when you live or die, and your numbers reduce. Humans, on the other hand, came up with ways to preserve the harvest through the lean months, through generations of trial and error, allowing us to spread to almost every climate in the world.   

The specific methods changed with culture and climate, but people knew how to dry, pickle, salt, bury, smoke and ferment, just as people used to know how to raise food, build shelters, birth babies, raise children and bury their dead. It is only in the last couple of generations, here in the West, that we have forgotten all these things, and expect to be taken care of.

Today, a shocking percentage of people -- a majority in America - don't cook at all. Seventy per cent of Americans are overweight, and a recent poll in England found that a third of food was thrown away uneaten. That constant stream of cheap and unhealthy food, though, depends entirely on a flood of fossil fuels, a stable climate, a healthy economy and many other factors that will fade as the years pass. More and more modern people are taking up backyard gardens, allotments and other ways of growing food, but these hobbies will be of only limited value unless they also relearn to stretch most of the harvest into the rest of the year.  

Preserving food against decay generally follows a simple principle: make it unpalatable for the things that would decay it, by making it too dry (dehydrating), too cold (freezing), too salty (salt pickling), too sweet (jams and cordials), too acid (vinegar pickling) or sterilised and removed from oxygen (canning).

Drying food is such a commonplace technique that it has become invisible to us; say “dehydrated” and most people think of Army rations, but of course our flour, corn, rice, barley, oats, beans, tea, coffee, herbs and spices all sit dried in our kitchens, and begin to go bad if touched by moisture. Most of us could not dry grains at home, or would need to, but you can certainly dry herbs from your garden; we hang our sage, rosemary and oregano upside-down in the kitchen pantry, along with nettles (for tea) and onions from the garden.

All manner of edible plants, moreover, can be dried for teas – dandelions, mint, clover, bramble shoots, nettle, chamomile, Echinacea, fennel, dill, anise, thyme, linden or St. John’s Wort. Fruit of all kinds can be dried: raisins, sultanas, sun-dried tomatoes (technically a fruit), apple rings, fruit rolls and any number of processed foods. Some of these tend to come from warmer climates and can be shipped here; raisins were a commonplace ingredient in Irish dishes for generations, a precious bit of fruit during the dark months, but native dried fruit could have done as well.
Drying meat into jerky is an old method of storing protein, and other people dehydrate chopped vegetables as soup starters. The Japanese dry seaweed to use in soups, and we here in Ireland pay high prices for it at sushi restaurants, yet ignore the thousands of tonnes of edible seaweed on our own shores.

Of course, the most familiar kind of indefinite food storage for many people is freezing, which still requires electricity but is a good place to start. Rather than eating out, ordering in or making individual meals one by one, you can make a large quantity of a dish in season and freeze it in a dozen meal-sized portions for later. It costs much less than making many individual meals, you can mix-and-match dishes, and the food retains most of its vitamins and flavour from the time it was picked.

Your climate will make some kinds of preservation easier or more difficult -- our damp climate in Ireland means we have to watch out for mould when drying, and you may need the help of your radiator or oven. On the other hand, we have very little snow or even frost here, and this is a good climate to simply leave things like parsnips, celeriac or other root vegetables in the ground through the winter, and yank them out as you need them. Some people put straw or bags over them to protect from frost, or pull them from the earth and store them in sand.

Finally, you can preserve some foods by changing them into other foods; we turn our milk into yogurt and soft cheese, and my first hard cheese experiment created some very nice Parmesan. More on how to make cheese soon.


Andy Brown said...

-Sharon Astyk offers an excellent on-line course on food preservation. I took it a few years ago and it was a great way to get going on experimenting with the various approaches.

Anonymous said...

We just got the materials to build a low temperature dehydrator. I'm very excited!

Allison McC said...

OK I want instruction on how to make cheese. Also, experimenting with tea will ALWAYS make me think of you!

jpbenney said...

The interesting thing is that, in geological terms, it is exceedingly unusual to obtain conditions where animals could obtain enough food to store.

Mark Huston has shown, that adjusted for the length of the growing season, primary productivity over the eastern hemisphere is lowest at 25˚S to 35˚S and over the western hemisphere (New Zealand as well as the Americas) in the tropics.

Low primary productivity in the tropics, Australia and southern Africa precludes animals from gaining enough food to keep any surplus. This explains their much higher species diversity than the extratropical northern and western hemispheres: there is no resource competition for surpluses.

What is telling is that the paleopedological record (the fossil record of soils as opposed to animals or plants) suggests that the fertile soils of the extratropical northern and western hemispheres never occurred between the Permian (280,000,000 years ago) and the Oligocene 40,000,000 years ago. This would mean that food storage by animals like pinyon jays (which are very like Australian birds in many ways as I note here) would have been simply implausible.

Perversely, scarcity of food can produce encephalisation beyond what occurs in the extratropical northern and western hemispheres - after all, humanity originated on the savannas of Africa which as Dustin Rubinstein demonstrates are an unpredictable and low-productivity environment. Still, the energy required for encephalisation in the low-energy environments of Australia and Southern Africa is testing at best, something overlooked by people like Richard Lynn.

Brian Kaller said...

I've heard of her course but never taken it - I should check it out.

I'd like to hear about the design, and what you make from it. Let me know how it goes!

I am going to try to make some more cheese later today, and get a bit more practice before I write about it.

Interesting. Do you think that a temperate climate allows for more kinds of storage, even if it offers less overall food?

When you say that fertile temperate soils never occured for a quarter-billion years, that's an astounding statement. What are ways we can tell what the soils were like, beyond extrapolating from rocks or fossils? If scarcity can accelerate brain development -- which makes intuitive sense even to a layman -- I wonder what that means for a future of runaway climate change? Let me know what you think.