“No Impact Man” is a popular documentary about Colin Beavan, a man in New York City who decides to “completely eliminate his personal impact on the environment” for one year. The concept is flawed. It is impossible for any living thing to survive without impacting its environment — simply by breathing, we humans convert oxygen into carbon dioxide. But the scope of the project got national attention, and Beavan’s “regular guy” persona helps him speak about sustainable living in a way that people understand.

Even better, a main focus of Beavan’s project was his commitment to eating locally. He, his coffee-addicted wife and his baby daughter survived the New York winter without buying food that was produced more than 250 miles away. But scenes of the family’s low-impact meals emphasized sacrifice. For the first few days of the experiment, which started in late fall, dinner consisted of potato and leek soup.

Given the extent of human history, sourcing food nonlocally is an extremely new phenomenon. If Beavan had done much research on how people lived for the hundreds of thousands of years before refrigerated airplane shipping compartments, he would have found that he skipped a step in preparing for his no-impact winter: food preservation.

We have it easier here in Texas, where local farmers offer delicious and nutritious greens such as broccoli and kale all winter long. But introducing basic food-preservation techniques could turn peaches in December and tomatoes in January into a guilt-free, local celebration.

Food goes bad when micro-organisms such as bacteria, yeast and mold eat our food before we do. To preserve food, we need to create an environment in which these organisms can’t survive.

Drying is one of the oldest food-preservation techniques. All living organisms, including the ones that spoil our food, need water to survive, so dried fruit and meat will last without refrigeration. Drying even enhances the flavors of some foods, including mushrooms and hot peppers. You can make foods such as apple chips or sun-dried tomatoes in your home oven ­­— instructions abound on the internet.

Canning, though now a mainstay of grocery-store convenience food, once took place in home kitchens. It requires cooking food at a high enough temperature to kill any microorganisms and keeping the cooked food in a sealed container so that no new organisms can find their way in. You can experiment with making jelly or canning fruit with only glass canning jars (available at any hardware store) and a large pot. Fruits are easier to safely can than vegetables or meat because they are more acidic, and some heat-tolerant bacteria, such as the one that causes botulism, cannot survive in an acidic environment. Canning vegetables and meat requires a pressure cooker. “Putting Food By” by Janet Greene, Ruth Hertzberg and Beatrice Vaughn is an excellent food-preservation resource with canning instructions that cover everything from apple butter to salmon.

My personal favorite way of preserving food, however, is by fermentation. Instead of killing all micro-organisms, fermentation techniques create environments in which only certain micro-organisms, those that make a food tastier, healthier or both, can survive. Yogurt is the fermented food best known for its health properties. Certain bacteria turn milk sugar, or lactose, into lactic acid. This creates a dairy product that’s easier for some people to digest and also gives yogurt its unique sour flavor. And because these good bacteria out-compete the disease-causing kind, yogurt lasts much longer without refrigeration than milk. You can make yogurt at home, and you can also make other fermented foods including sauerkraut, pickles, miso and beer. Sandor Ellix Katz’s book “Wild Fermentation” gives easy-to-follow instructions as well as fascinating historical and scientific explanations of fermented foods from around the world.

Eating local is about preserving the environment, but it’s also about pleasure — the pleasure of eating fresh, healthy foods and the pleasure of knowing who grew them; the pleasure of preparing food and sharing your recipes and techniques with others. Did your grandmother used to can her own jelly or make her own pickles? Maybe she can teach you. Learning basic food preservation is a great way to get in touch with your food, your environment and your culture.