Food preservation is a useful way to prevent your harvest from going to waste, but it’s also a fantastic way to savour the summer harvest when it’s cold outside and you’re reminiscing about warmer days! Here’s a quick summary of some food preservation techniques that we enjoy doing at home. For simplicity, we’re assuming that you don’t have a cold room, so we’ll focus on storage options in your kitchen.
Appropriate for winter squash, pumpkins, garlic, onions, potatoes, and sweet potatoes. Curing involves drying out the outer rinds of vegetables to seal them and preserve the insides.
- The vegetables should be fully mature and should be free of any deep cuts that would prevent the rind from sealing. Most vegetables should be cured in a sunny, airy place – this can be done by hanging them indoors or spreading them out in a dry, outdoor area. The exception to this technique is potatoes, which should be cured in a humid, shady place.
- Turn the vegetables every few days so that all sides are exposed to open air. The vegetables should be cured for approximately 2-3 weeks in total, until their skins are dry.
- As a tip, vegetables such as squash and potatoes are best cured by leaving them on/in the ground where they grew, unless conditions are too wet.
Appropriate for herbs and tomatoes. Drying involves the removal of all water, which preserves vegetables by depriving fungi and bacteria of the water that they require to spread.
- Drying herbs can be as simple as hanging them in bunches, typically for about a week, until they easily crumble in your hands. If required, rinse your herbs before you hang them in order to clean them. As an easier alternative for teas and spices, you can dry herbs in the microwave. Place them on a paper towel in the microwave and give them 30-second bursts on high until they are slightly crumbly, then switch to 10-second bursts until they are completely dry.
- For tomatoes, slice them (1/2cm to 1cm thick) and then lay them to dry in the oven or in a food dehydrator. It will take about 12 hours or more at around 150oF, depending on the size of the tomato pieces. Once they are fully dry, they can be stored in freezer bags, in sealable plastic containers, or in vegetable oil.
Appropriate for herbs, berries, and most vegetables.
- Freezing your herbs can be as simple as pureeing them and pouring them into ice cube trays. It can also involve putting whole-leaf herbs (such as mint) into an ice cube tray, covering them with water, and freezing them.
- For berries, simply lay out your unwashed berries in a single layer on a baking tray and freeze them. Once they are completely frozen, they can be piled into freezer bags or a sealable plastic container for long-term storage in the freezer.
- Most vegetables should be blanched before freezing to prevent them from emitting ethylene gas within the freezer bag. Boil them for 2-3 minutes in rapidly boiling water, cool them in ice water, drain and dry fully, and then place them into freezer bags, allowing a little bit of room for air expansion.
Appropriate for most vegetables except for brassicas, summer squash, celery, eggplant, and lettuce. Canning involves sterilizing fruits and vegetables and then storing them in a sterile environment, where they may be kept for months without risk of contamination. We recommend referring to reputable canning resources to ensure that you are following safe canning methods. Here’s a quick synopsis:
- The water-bath method of canning is ideal for high-acid foods. It involves placing the food into sterile canning jars (with new or nearly-new lids) and lowering them into a bath of boiling water for 5-10 minutes to sterilize the contents.
- The pressure-canning method is for all vegetables but particularly for low-acid foods that are more susceptible to pathogens. It involves placing the food into sterile canning jars and placing those jars into a pressure canner for a prescribed amount of time.
- For both methods of canning, ensure that all ingredients and tools are sterile before use, ensure that all air pockets are squeezed or tapped out of the jars before canning, ensure you leave enough headspace below the lid, and ensure that the lids are sealed once the jars have cooled. If anything goes wrong with these steps, immediately put the jars into your fridge and consume within a couple of weeks.
Appropriate for cabbage, cucumbers, beans, hot peppers, beets, radish, etc. Fermentation involves combining liquid and beneficial bacteria to preserve vegetables, enhance their flavours and add health benefits. Fermentation is used for many foods we find in stores, including bread, cheese, yogurt, chocolate, beer, wine, kimchi, sauerkraut, pickles, etc.
- Fermentation is done by first massaging the vegetables to break down their cell walls. Ideally, the vegetables are also sliced to increase the surface area available to the beneficial bacteria. Then combine the vegetables with filtered water, salt and/or a starter culture in a container. Add a weight on top of the mixture to ensure that all vegetables remain submerged and place a loose cover on top. Do not seal the container as pressure will build inside. Leave the mixture at room temperature until it achieves the flavour that you prefer.
The above summary is just a sampling of different methods that are often used to preserve your harvest. You should choose the method that is best for you – each has its own advantages and disadvantages. The key message is to do whatever you can to extend the period in which you can enjoy your harvest. For each method, be sure to follow a more comprehensive set of instructions to ensure that your food is safely preserved.