When you know how to preserve food at home, you can eliminate food waste in your home, reduce your carbon footprint and help conserve agricultural resources.
Food preservation techniques are also valuable for households that buy fresh food in bulk or grow their own and want to stretch the food as far as possible. It will save you many trips to the grocery store or farmer's market, and each less trip can help reduce carbon emissions.
Knowing that food waste will eventually decompose and turn into soil nutrients is why some folks fail to recognize food waste as an actual problem. Our compilation of food waste facts and statistics shows how wasteful we are with our food.
Food waste takes up landfill space, and some foods may not decompose for a very long time because of anaerobic conditions. Meanwhile, rotting food emits tons of harmful greenhouse gases. If food waste continues unchecked, the chances of widespread food scarcity increase. Food waste is a problem across the globe, and you can help by learning how to preserve food at home and doing your bit to reduce the food that ends up in the bin.
Related: When preservation isn’t an option because of smaller amounts, inedible scraps, or foot types unsuitable for storing, the next best option is to compost your food waste.
The goal of preserving food is not just to prevent spoilage but also to maintain its nutritional value and tastiness. You can preserve foods using the following methods.
Freezing foods is possibly the most common method of home food preservation. It is as easy as opening your freezer and placing the food in it. Many types of food are easily preserved using a freezer; freezing food stops bacteria and mold from growing on it.
Manufacturers differentiate between a refrigerator and a freezer. However, note that the main difference between the two is the pace at which the temperature cools. A freezer uses more energy and moves the refrigerant around faster than a fridge does.
Freezing your food has many advantages, but it's not a long-term solution for all kinds of foods. Foods like custard, cream, and yogurt are cream-based and don't stay unspoiled for long in the freezer, while water-rich vegetables like melon, cucumber, radish, and celery won't fare well in the freezer for a long time.
Fresh fruits and vegetables contain enzymes that ripen them. When frozen, those enzymes are slowed but not completely stopped, so the fruits and vegetables will still ripen and eventually go bad. But you can prevent this.
Before you freeze fruits and vegetables, boil them in a pot for 2 to 5 minutes and transfer them straight into a bowl of ice-cold water for an equal amount of time. Then drain the water, pat your produce dry and freeze them.
Bagging frozen food in an airtight bag before freezing extends the shelf life. A ziplock bag is straightforward to use, but silicone bags are more eco-friendly and reusable. You can fill them up with food, press down on them to remove air, and close it up for refrigerating.
Sealing frozen produce in airtight bags helps to preserve food by preventing the formation of ice crystals (frost). Sometimes it helps to flash freeze the produce, placing it in a tray and letting it become more solid before bagging it.
Using non-iodized salt to preserve food is an ancient practice that still works today. Salting food reduces its water content and prevents the growth of microbes that would spoil it. Using salt alone to cure food is called salt curing, corning, or salting.
People also use sugar to preserve food, such as jams and jellies, as it also delays spoilage. They often use a combination of salt and sugar to preserve food. This is what most people understand as curing. Apart from salt, sugar, and recipe-recommended spices, sodium nitrate/nitrite is sometimes included in curing mixtures.
Sodium nitrate/nitrite is controversial, has been linked to cancer, and is considered unsafe and unnecessary by most experts. However, many commercially cured foods and premixed curing mixtures usually contain it. The meat curing industry has stated that nitrite is supposed to protect cured foods from botulism spores. Although some companies add ascorbic acid or erythorbic acid to cured meat products to reduce the harmful effects of nitrites, creating your mixture at home with nitrate can be extremely risky.
You can rub the cure ingredients on the meat, put it in a plastic bag, seal it, and let it cure in a refrigerator. Fish is better wrapped in cheesecloth. Another method is to layer the meat or fish in a pan with the cure and weigh the food down to speed up liquid extraction.
The curing period depends on the type of food, the thickness of the slices, and how you want it to taste. Seven days per inch of thickness is the standard duration, but a side of salmon is cured within three days. After curing, you should wash the food and age it. Smoking the food after that is optional for taste and flavor.
There's also a meat curing method known as wet curing. It is simply dissolving the cure ingredients in water to create a brine. You can either soak the meat in the brine, or you can inject the brine into the meat with a meat pump. A heavy object is often used to weigh down the meat in the liquid.
Wet cured meat is smoked before storage in a fridge or a cool room. Another type of curing technique combines dry and wet curing methods, which prevents spoilage more than using either method alone.
Cucumber or gherkins is most likely the first thing that comes to mind when people hear of pickling; however, pickles are not the only type of food that can be pickled. Other foods that can be pickled include eggs, beets, peaches, peppers, avocados, olives, garlic, asparagus, apples, carrots, and lots more.
Pickling involves using vinegar or brine to preserve food as they create an acidic environment that kills microorganisms. Brine recipes vary, but salt and water are always needed. Some recipes include sugar and spices for pickled vegetables.
To pickle food, you soak it in a jar filled with vinegar or brine and ensure it is completely submerged. Some foods need to be sliced, peeled, or frozen before you soak them; others can be pickled whole.
Once the soaking is done, you should put the pickle jar in a refrigerator. In about a week, most pickles are ready, but the food and recipe may call for more time. You'll be able to enjoy your pickled food for about two months; if it is vacuum sealed, it will last even longer.
Some of your favorite foods, like cheese, kombucha, sourdough bread, sauerkraut, kimchi, and yogurt, are obtained through fermentation. Wine, beer, apple cider vinegar, and soy sauce are also results of fermentation.
In preserving food through fermentation, microorganisms like yeast and bacteria act on foods. The chemical reaction turns carbohydrates into organic acids or alcohol under anaerobic conditions. Fermentation is not the same as food going bad.
Fermentation is an ancient form of food preservation that is about 1000 years old. Fermented foods are good for gut health and general body nutrition.
Sea salt and water are good enough as a fermentation liquid (brine), but you can use whey or a starter culture if you want to. For every 100 grams of vegetables, the brine needs 2 grams of salt. Use water that is free of chlorine and fluoride. Add the veggies to the fermentation liquid so they're completely submerged, and weigh them down.
You can use fermentation crocks or jars, some cheesecloth, and some sort of weight to keep certain foods below the surface of the liquid. The weight could be special fermentation glass weights made specifically, a smaller jar, or a clean rock. Leave the mixture in a room temperature environment for three days; if it's not as acidic as you would like, give it more time. When the fermented food is ready, put the jar in a fridge for long-term storage. It will last for a few months.
You can ferment vegetables like carrots, chili, baby eggplant, cucumber, beetroot, cauliflower, zucchini, celery, and green tomatoes. They can be fermented separately or as a vegetable mix with fresh spices. You can even ferment green leafy vegetables like lettuce, spinach, and kale. You'll find this fermentation tutorial very useful.
Drying foods to preserve them is an age-old preservation method. Centuries ago, people first dried food under sunlight to last into the colder months. When food dries, the moisture content in it evaporates, restricting the growth of mold, bacteria, and yeast growth. Meat, fish, legumes, vegetables, and spices are some foods preferably preserved by drying.
You can not dehydrate avocados or fatty parts of meat due to their fat content. Dehydrating eggs is possible, but rehydrating them at the point of consumption isn't easy and can result in an off-putting taste. With technologies like freeze drying, ovens, and electric food dehydrators, food drying has become so much easier and faster.
You can store dry food in a mason jar or vacuum-sealed bags. Just keep the food in a cool and dry place. If the process was done incorrectly and the water content wasn't eliminated, the food would become moldy over time.
To freeze dry food, you can put it in a freezer, in a freeze-dryer, or on dry ice. It takes several weeks to freeze dry with a freezer, but a freeze dryer gets the work done in about a day.
A freeze-drying machine freezes food way below the freezing point. Then it reduces the pressure, which causes the solid ice in the food to become gas without melting into liquid, a process also known as sublimation. Freeze-dried foods maintain their shape, fresh flavors, and fresh appearance even with zero water content.
Canning is a preservation technique that sterilizes mason or glass jars and seals food in them in a vacuum seal (airtight condition) using heat. That way, all the microbes in the food are killed, and the seal prevents any more micrograms from entering. There are two methods for canning food at home. We have water bath canning and pressure canning.
Not all canned food involves tin cans and special machinery. The person who invented canning foods as a preservation technique used glass jars. So with some mason jars, you can store a variety of foods, including meat and fish, for a long time.
Note that not every kind of glass jar is suitable for home canning, so reusing mayonnaise jars or milk bottles and the like may not work. If you are going to try using jars from other products, try going through the process with a single jar before going all in. Unsafe canning practices can result in glass shattering and cause injury.
Mason jars, specially made for canning, can withstand high temperatures and come with zinc lids. You can find them in your local supermarket and purchase jars and lids separately. That way, you can safely reuse one mason jar for a very long time by simply changing the lid. Find out more about the dos and don'ts of canning jars here.
Botulism is food poisoning caused by a bacteria called Clostridium botulinum and strains of the Clostridium baratii and Clostridium butyricum bacteria. It affects the nervous system and can cause paralysis or even death. Botulism is rare, but contaminated food is the most common way of catching the illness.
Botulism-causing bacteria thrive in anaerobic environments, where there is no air, and can survive hours of boiling. However, they can't survive on high-acid foods, so any food with a PH of 4.6 or lower can be safely canned using any of the canning methods. Low-acid foods are more susceptible to botulism spores. Luckily, pressure canning and adding lemon juice or vinegar provide a safety net.
The bacteria that cause botulism can be killed with very high heat, but that would be way above the boiling point of water. That's why it's best not to use water bath canning for low-acid foods. The water bath temperature can't go higher than the boiling point (212ºF/100ºC). In a pressure cooker, the temperature can get hotter than 240ºF (116ºC)
This method requires a large pot, your jars, a canning rack, and a jar lifter. You put the clean open jars in a pot of boiling water for about 10 minutes on medium heat. Remove one of the sterilized jars with a jar lifter, fill it with food, seal it and return it to the pot before picking out another.
The food must have been processed beforehand, following a canning recipe; there are many different recipes for all kinds of foods. The recipe you choose specifies the appropriate liquid topping and how long the filled jar must stay in the boiling pot. It is important to sterilize the lids and other utensils used by soaking them in hot water.
Water bath canning can preserve food for months and even a few years. However, it is most suitable for acidic fruits, apples, berries, grapes, cherries, peaches, tomatoes, and any pickled foods. You can also add lemon juice or vinegar to low-acid vegetables if you want to use water bath canning to preserve them.
This method is better for low acid foods because it uses a pressure canner which provides more heat during canning. Low-acid foods include most vegetables like green beans, carrots, corn, red meat, poultry, seafood, and dairy. Pressure canning is recommended for preserving combination recipes like stock, stews, and soups too.
You'll need a special instrument called a pressure canner. It has a dial or weighted gauge that measures steam pressure as it builds up inside the canner, which allows you to regulate the heat by turning it up or down. The canner is different from a pressure pot or cooker. You'll need other safety instruments like a pot holder, a jar lifter, and a magnetic lid opener.
You begin pressure canning by boiling 2-3 inches of water in a loosely covered canner until it's simmering. Then you pour a little bit of water into the jars so they can stay upright in the boiling water and place them in the canner. The lid should still be loosely closed at this time until the jars get steamy hot.
Then bring out the jars, fill them, and return them to the canner one after another. The jars shouldn't cool while you are filling them up. Use a tiny spatula to get rid of air bubbles in the jars before you screw on the lids. When all the jars are filled, lock the pot securely, turn up the heat and allow steam to flow out through the vent pipe for about 10 minutes. Then you can reduce the heat and begin timing the food as your recipe specifies. When time is up, allow the canner to completely depressurize before opening it.
You shouldn't substitute a pressure canner with pressure pots because the pots are significantly smaller than a standard canner, and that causes the pressure cookers to heat up and cool down faster than pressure canners. This difference could result in under-processed foods and increase the risks of leaving an opportunity for dangerous botulism.
Before the refrigerator was invented, people kept their food in the coolest places in the house. Those were places like root cellars, pantries, and basements with no heat insulation. Just like with a refrigerator, food preservation in these places slows down the growth of microorganisms in the food.
If you have a root cellar or an unheated basement, you can store foods like beets, onions, potatoes, yams, cabbage, and turnips there. Unlike freezing, cool room food storage doesn't require a lot of special preparations on the food before storage. The foods can be preserved raw and whole.
Tomatoes, peppers, soft fleshy fruits, and leafy vegetables don't do well in root cellar storage.
You shouldn't wash root vegetables like carrots and turnips before storing them in a root cellar or any cold room. You can just dust the soil off them. Before storage, you should cure some other products like winter squash and raw meat.
To store fruits like pears and apples using the cool room food preservation method, you'll need to wrap each fruit individually with paper. The paper wrapping stops the fruits from heating up and slows the release of pears ethylene gas which would spoil them.
Also, if one fruit gets spoiled, the wrapping stops it from spoiling others in the bunch. Using only paper wrapping is best because other materials may cause heat.
Like salt, alcohol draws water out of food and inhibits bacterial growth. Food preservation with alcohol has been used for a very long time to preserve fruits. The German dessert, rumtopf, is a centuries-old recipe made by preserving summer fruit in rum. Alcohol-preserved fruits can be used later for delicious desserts like brandied fruits or homemade flavored alcohol.
Alcohol immersion is like pickling; you submerge the fruits in any spirit of choice, cover them, and store them. The types of spirits you can use include vodka, rum, wine, cognac, and brandy are all good options. You can preserve vanilla beans, strawberries, blueberries, plums, peaches, cherries, and citrus fruits with alcohol.
Depending on the ABV of the spirit you use, the fruits may be preserved for a few weeks to over a year depending on the ABV of the spirit you use. We recommend using spirits with 35% ABV and above.
You can preserve food like vegetables and spices in extra virgin olive oil. The oil is a natural preservative that coats the food, seals it from the air, and inhibits the growth of most microorganisms. Some of the foods usually preserved in olive oil are tomatoes, green beans, peppers, cheese, mushrooms, and fish. You can also preserve fresh herbs with olive oil.
This home food preservation method is straightforward to practice. You just need to ensure that whatever food you make is appropriately prepared. Because olive oil preserves are in an anaerobic environment, you should ensure they are correctly stored to avoid botulism. Check out this preservation guide from experts at Oregon State University.
Most foods can be preserved using the preservation methods we described in this article. Home food preservation is an enjoyable process, and you can start with some simple food preservation techniques. Choose to preserve food today to help prevent excess from going to waste.
Jen’s a passionate environmentalist and sustainability expert. With a science degree from Babcock University Jen loves applying her research skills to craft editorial that connects with our global changemaker and readership audiences centered around topics including zero waste, sustainability, climate change, and biodiversity.
Elsewhere Jen’s interests include the role that future technology and data have in helping us solve some of the planet’s biggest challenges.