Canning, Freezing & Fermenting: Preserving Vegetables Grown from Seed
*Photo credit: Nancy Hallberg
If you’re new to vegetable gardening, you may be surprised and overwhelmed by the bounty of your harvest. It’s likely to be much more than you’re able to consume while the vegetables are at peak freshness, in which case, you will need to consider freezing, canning, fermenting, or dry-preserving them so you can enjoy them over time.
Consider this: you’ve worked really hard all spring and early summer planting your vegetable seeds, carefully tending the seedlings, mulching, watering and generally fussing over your beautiful plants as they’ve grown. We know from experience, it’s really exciting when it’s finally time to harvest and enjoy the fruits of your labor. Part of the fun is figuring out creative and novel ways to prepare all those vegetables. The problem is you’re going to need to use them up before they lose their freshness and spoil, which is a tall order unless you have a very large family or friend-group to feed.
The high percentage of water in most fresh vegetables and the fact they continue to “breathe” through enzymatic activity even after they’ve been picked causes them to start losing their nutrients along with their moisture, dispiritingly quickly. Nearly half of some vegetables’ nutrients are lost within a few days unless the vegetables are cooled or preserved. Even in the refrigerator, nutrient loss will resume within a week or two. And then after that they start to decompose. That seems like a waste after all the time and effort you put into growing them. It makes much more sense to figure out a method for preserving them so you can enjoy them all year long.
For advice on various methods of preserving produce, we reached out to one of our longtime employees and in-house “produce preservation expert”, Darcy Hunt. We have incorporated Darcy’s advice into the following summary of different common preservation methods.
Freezing Vegetables
This is a relatively easy way to retard enzyme activity and prevent spoilage while retaining the natural color, fresh flavor and high percentage of vegetables’ nutritional value. One advantage to freezing vegetables is you can easily do it in small or large batches and can mix and match vegetables together. And, you don’t have to worry about acidity and salt levels when freezing vegetables, unlike in the canning process.
The downside of freezing is that produce doesn’t reliably last as long in a frozen state as it would if it were canned. In addition, if you live out in the country where you periodically lose power during storms, with no generator backup, your prized frozen veggies will likely go bad before you can consume them.
There are a few simple steps involved in this process. Most fresh vegetables make good candidates for freezing including asparagus, broccoli, corn, green beans, and tomatoes, to name a few.
- To avoid spoilage or bacterial contamination, it’s important to choose vegetables that are in excellent condition.
- Clean the vegetables and your work space thoroughly.
- Blanche the vegetables (blanching involves quickly dipping them in boiling water for 3-5 minutes, depending on the vegetable and then immersing them in cold water to cool them down, arresting the cooking process.)
- Seal them in ziplock bags, or even better, invest in a vacuum sealer and vacuum seal them - thus more effectively removing all the air (air contributes to spoilage).
- Place them in the freezer. They should last 8-12 months there, properly stored.
Dehydrating Vegetables
This is one of the oldest—and easiest—methods for preserving food and requires the least amount of energy and storage space. Dehydration involves removing water or moisture from the vegetables by heating them up and allowing the moist air to escape in the process. You can dehydrate vegetables in your conventional oven at a low temperature of 140-150 degrees, over time, leaving the oven door open a few inches to allow moisture to escape. Convection ovens and commercially made dehydrators also work well. Following are the steps involved in the dehydrating process:
- Similar to freezing, choose vegetables that are in good shape and clean them thoroughly.
- Vegetables that lend themselves well to this process include: corn, carrots, garlic, onions, mushrooms, parsley, parsnips, peppers and potatoes. Darcy says one of her favorites is dehydrated tomatoes.
- Blanche them first, but in this case, add ½ teaspoon of citric acid per quart of water - this serves as an anti-microbial and anti-darkening agent. (Garlic, onions, peppers and herbs don’t need to be blanched.)
- Drain the blanched vegetables and place them on drying trays to start the process.
- Place them in the oven or dehydrator for the prescribed time period.
- Store dried vegetables in airtight containers to prevent them from absorbing moisture in the air.
- Storing them in a dark place will help them retain their nutrients.
Canning Vegetables
This is the process of packing vegetables in a glass jar and sealing them with lids to prevent bacteria growth and is a bit trickier than the two methods described above but you might prefer the outcome. Canned foods not only last on the shelf for a long time, they retain much of the quality they had when they were fresh.
There are two types of canning methods—water bath and pressure—each appropriate for different types of food. It’s imperative that canning is done in a pristine environment through a precise set of procedures to ensure safety. Vegetables are prone to bacterial contamination in a high moisture, low acid environment, so you need to know what you’re doing. There are many books and online resources that can provide expert guidance; we recommend consulting your local Cooperative Extension Service
Fermenting Vegetables
The basis of fermenting vegetables is lacto-fermentation which not only serves to preserve them, it enhances their nutritional value with well-known digestive tract benefits. While kimchi and sauerkraut are popular examples, almost any fresh grown vegetable can be fermented for use throughout the year. The fermentation process involves placing vegetables in a container—there are ceramic crocks made for just this purpose—and covering them with water and adding salt, whey, kefir grains or a starter culture. As with the other methods of preservation described above, it’s crucial to use vegetables in excellent condition and prepare them in a pristine workspace. For additional information, consult your local cooperative extension service or one of the other many online resources available.
Make Hay While the Sun Shines
Summer is supposed to be the time to kick back and relax, but if you’re a gardener, it seems like your work is never done. And there’s no getting around the fact that by choosing to preserve the vegetables you’ve grown, you’re actually going to have more work on your hands, at least in the short term. But we say it’s definitely worth it. Think about how nice it’s going to be to enjoy your delicious, nutritious produce in the dead of winter.