Food preservation doesn’t need to be complicated; in fact, most methods are deceptively simple. We preserve food every day when we put our leftovers in the refrigerator. Most of the time, we’re trying to kill or inhibit the growth of bacteria, which is what this post will cover. Fermentation – the process through which we get cheese, coffee, and alcohol — is a whole other game.
As the summer bounty comes to an end, let’s take a look at some of the easiest ways to keep the local harvest providing all year long.
Drying
Some foods practically dry themselves. Legumes (like peas or beans) will dry on the vine in their pods. But most of us don’t have cowpeas climbing the backyard fence. Instead, we have farmers markets… though the season is coming to an end. This week, you might be able to get some of the very last tomatoes.
One of the least labor intensive ways to store tomatoes is to dry them. By running the oven at a low temperature for a long time, you can create an environment where all of the moisture will be sucked out of the fruit. (Moisture is conducive to the growth of mold). Store the tomatoes in the fridge or freezer, and cover them with olive oil.
Want to dry fruit? Follow the same process, then follow up by curing it for a couple of days.
Curing
Technically, drying food is curing it. Curing is to drying what rectangles are the squares. (SATs, anyone?) Salting can be used as a form of curing, too. Basically, curing preserves food by removing all moisture. Garlic, for example, won’t keep unless cured. And sometimes, curing has an additional effect. Sweet potatoes don’t get sweet until their starches have time to turn into sugars!
Here’s a great explainer on curing garlic, and here’s one on sweet potatoes. Both can keep for months when cured properly.
To cure dried fruit? Make sure any and all moisture has evaporated by leaving it out on the counter for a couple of days.
Jellying
Jellying is the process through which food is preserved into, “A soft, semisolid food substance with a resilient consistency, made by the setting of a liquid containing pectin or gelatin or by the addition of gelatin to a liquid, especially such a substance made of fruit juice containing pectin boiled with sugar.” Apple peels naturally contain pectin and can be used as a substitute, but beginners should stick to the packaged stuff.
How do you make a jelly? Mix sugar, water, pectin, and fruit and/or veggies. Food in Jars has some great recipes and detailed instructions. This time of year, green tomatoes are in season, and you might be able to find the last hot peppers. But as Marisa McClellan’s website shows, it’s easy to get creative.
Canning
While the life of pickles and jellies can be extended in cans, a food doesn’t have to be immersed in vinegar or sugar for this form of storage. (Did you catch Alexandra’s post on the artisan pickle?) Tomatoes, for example, are regularly canned in a way that preserves the integrity of the tomato flavor. Well, the integrity of a cooked tomato.
Canning food preserves it because it creates an anaerobic environment. With all of the air gone, most organisms find it difficult to grow. The scariest exception is botulism, which is why you should always follow tried and true canning recipes. Hot water baths are the easiest canning method (see link below), but if a recipe tells you to use a pressure canner… use it.
Though it’s hard to read, this is my favorite site for canning recipes. It has lots of good tips and always follows safety protocols.
What methods of food preservation have you used?