It wasn't that long ago that Americans were eating off the land and taking steps to preserve stashes of food to subsist on in the cold, winter months and as a way to make fruit, vegetables, and meat last long past its natural expiration date. One reason people could do this was thanks to a French chef who discovered a way to pack food in airtight containers. He discovered the process for removing air from inside the jars and used high temperatures to prevent bacteria from growing and spreading…
Food that previously had a shelf-life of a few days could now be enjoyed months or years down the road. The process, known as canning, successfully preserves meat, fruit, fish, dairy, and a variety of condiments. At first, foods were packed preserved in tin cans -- long before can openers were invented. These days, canning is making a bit of a resurgence because it's an excellent way to save money, it prevents food waste, and for some folks, it's a fun hobby.
There is a science to preserving and canning food. And there are two primary canning methods.
Water bath canning is when you pack acidic foods into jars and cover the opening with a lid. Placing the lidded jar in 212-degree F boiling water eliminates air from inside the jar. It also seals the lid and creates a vacuum. The foods that fare best under the water bath canning technique are those with high acidic levels, and water bath canning creates an environment that is hostile to bacteria and prevents them from thriving.
- Condiments, like salsa
- Jam, jelly, fruit pie filling
Pressure canning is when low acid foods are packed in jars and then the jars are heated to at least 240-degrees F in a pressure cooker. During the pressure canning process, any sort of environment that welcomes the growth of foodborne bacteria is completely destroyed. The amount of time you need to pressure cook low acidic canned foods depends on the type of food and also the altitude at which you're canning.
- Canning Tips
Choose produce, spices, and herbs wisely. First, sort out items that have an imperfection. It's OK to buy misshapen, dented, bruised, or nicked fruits and veggies to eat and use in recipes right away. But for food preservation and ensuring a long, healthy shelf-life, you want to use only the freshest, ripest, and least spoiled foods, herbs, and spices.
What You'll Need for Home Canning
For the water bath canning process, you can buy a state-of-the-art water bath canner, or use a large pot with a tight-fitting lid. Just be sure the pot is large enough for the jars to be fully submerged in water, and there's enough space, so the jars don't touch. During processing, a jar can break if it bumps up against another.
You may be tempted to use recycled jars for canning, but the experts say it's not a good idea. A jar designed for canning is able to withstand very high temperatures (for killing bacteria and preventing growth). There also needs to be a tight, secure seal between the jar and lid. So save that empty Hellmann's jar to stash bulk sugar and spices; but not for canning. The best vessel to use for canning is a mason jar. These wide-mouth containers are specifically designed for food preservation and high temperatures. While the actual jars and screw bands are recyclable, you must use a new lid each time you seal a batch of food. When you close a jar, a sealing compound creates a vacuum. A lid has just one shot at making an airtight bond. Screw bands should be replaced when rust appears, or any part of it becomes misshapen.
Water bath canning and pressure canning pots come in different sizes for large batch and small batch canning. On the small end, a 12-quart pot, for example, can hold six quart-sized canning jars or 7-pint jars. A jar canner with a 33-quart pot holds 13 half-pint jars and 9-pint jars.
Here are some foods you can preserve using the water bath canning method:
- Peach jam
- Apple butter
- Tomato sauce
- Green tomatoes
- Dill pickles
For the pressure canning process, you will need a special pot that has a lid that can be firmly and tightly sealed. The newer countertop pressure canner appliances have design features like a pressure gage, cover locks, and a vent to release steam and pressure. Some are designed for canning and also cooking food. And some a multipurpose water and pressure canners.
Here are some foods you can preserve using the pressure canning method:
- Green beans
- Red peppers
- Sweet potatoes
- Asparagus spears
- Beats, whole or sliced
- Fresh greens
All sorts of different meats can be preserved for a few years, including beef, lamb, pork, and sausage. To prepare meat for canning, it's OK to season it with salt and pepper, but experts suggest avoiding other seasonings because it can cause the meat to have an off-flavor taste later on. Shape meat into flat patties, small balls, or short links (for sausage). Cook the meat until it's lightly browned and then pack it into heated mason jars. Add boiling liquid, like water, broth, or tomato juice. Leave about 1 inch of space between the lid and the top of the food. Add a teaspoon of salt per quart to each jar (this step is optional). Then wipe the jar's rims with a damp, lint-free towel or paper towel to remove any debris that could create an opening for air. Now you're ready to place the jars in your pressure canner.
If you have a tomato garden and can't eat or cook through your crop fast enough, then canning tomatoes may be just thing you need. To remove the tomato's skin, wash them under cold water to remove dirt and then dunk them in a vat of boiling water. It takes from 30 to 60 the skin to split. Take the tomatoes out of the hot water and straight away dunk them into a pot of cold water. Now the skin should be able to slip right off. Remove the core and quarter the fruit. Put about half of the bushel in a large heated pot and crush the tomatoes as you stir continuously to prevent burning. Once the crushed tomatoes come to a boil, add the remaining bushel. You do not need to crush these. Simply continue stirring the contents of the pot. Allow the gentle boil to go on for about 5 minutes. In the meantime, put some lemon juice or citric acid into the mason jars and a teaspoon of salt per quart (salt is optional). When your tomatoes are finished boiling, fill the mason jars nearly to the top, leaving about 1/2 inch of space beneath the lid.
Canning is economical, and it's environmentally friendly. If you're making a large batch of strawberry jam, for example, and using a cherished recipe that was passed down from mother to daughter over several generations, then you don't want to feel pressured to eat the entire batch, but you don't want to waste a single teaspoon, either. That's why canning is an important skill to have.
For canning jam and preservatives, you need to use the water bath canning method — heat mason jars in simmering water. After the strawberry jam is made, and while it's still hot, ladle the recipe into the hot jars. Leave 1/4 inch of space between the jam and lid. Place lid and band on the jar. Process in the boiling water canner for about 10 minutes. Your homemade jam will be preserved for up to two years.