How to preserve the fall harvest

Lauren Bethke

As fall arrives, our gardens here in Minneapolis are full of late-season bounty. Tomatoes ripen all at once, zucchini seems endless, and cucumbers pile up faster than you can eat them fresh. Preserving these crops allows your hard work to carry into the colder months, letting you enjoy garden-fresh flavors all year. Three of the most common and accessible methods are canning, dehydrating, and freezing. Each of these methods offers different benefits depending on the vegetable and how you plan to use it later. Read on for some background information about canning, dehydrating, and freezing, and tips for preserving tomatoes, zucchini, and cucumbers – three of the most prolific fall producers.
Canning has been a popular preservation method for generations. However, methods have changed in recent years based on scientific research, so keep in mind that your grandmother’s recipes may no longer be considered safe to use! When proper procedures are followed, canning allows produce to be stored at room temperature for 1-2 years. Safe canning recipes developed and tested with modern techniques can be found on University Extension websites or the Ball Canning website. Use caution when consulting older canning cookbooks and recipes.
Dehydrating removes moisture from produce, creating lightweight foods that are fairly shelf-stable, depending on how much moisture is removed. This method is excellent for saving space and creating snacks or ingredients that can store well for months in airtight containers (or longer if you keep the containers in the fridge or freezer). A dehydrator works best, but you can also dehydrate produce using an oven on its lowest setting.
Freezing is one of the simplest preservation methods and can be the best choice when you don’t have a lot of time. Unlike canning, you don’t need special recipes for freezing and you can use your family’s long-time favorites. However, some vegetables (especially those with high water content) can become mushy when frozen and then thawed, so consider the end use of your produce when deciding whether to freeze it or use another method.
Tomatoes are one of the most versatile crops to preserve. Canning is a popular method because tomatoes are naturally acidic, so they are less likely to pose food safety issues. There are tons of great recipes for canning tomatoes, including as a puree, sauce, salsa, or even a savory jam. Dehydrating tomatoes is another good option as it creates concentrated flavor. Cut tomatoes in half or slice them before dehydrating to create dried tomato pieces that are great for soups, salads, or as part of a cheese plate. Freezing tomatoes is probably the simplest option: you can make and freeze tomato puree or sauce, or even put whole tomatoes in the freezer without doing any sort of pre-processing. Once thawed, the skins slip off easily. Personally, I like to make canned salsa and tomato jam, and I freeze quite a bit of tomato sauce, as well. And at the very end of the season when I don’t have much time, I will freeze several bags of whole tomatoes to thaw and cook later!
Zucchini, famous for its prolific yields, can also be preserved in several ways. Because zucchini is a low-acid vegetable, canning plain zucchini requires a pressure canner, which is a more complicated endeavor than simple water bath canning. Another option would be to pickle zucchini slices in vinegar brine, creating tangy pickles similar to cucumbers. This makes zucchini acidic enough for water bath canning. You can dehydrate zucchini and create chips for snacking or pieces that can be rehydrated in soups or casseroles. Dehydrated zucchini can even be powdered and added to sauces or breads for extra nutrition. In my opinion, freezing is the easiest way to preserve zucchini. If you freeze portions of grated zucchini, they are easy to thaw and use in breads, muffins, casseroles, or soups.
Because of the high water content of cucumbers, dehydrating or freezing them don’t always yield the best results, but they’re great for canning pickles or relish. Personally, I make a lot of cucumber relish throughout the season - it’s a great way to add a bit of summer to dishes all year round, and it makes a lovely gift too!
When you preserve the fall harvest, you save food and extend the joy of the garden into the cold months ahead. Check out the University of Minnesota Extension website for more advice on preserving your homegrown produce, including classes, articles, and FAQs about many different food preservation methods.
For more information, check out the University of Minnesota Extension Yard and Garden website. Extension resources are written by experts and contain the latest and most reliable research-based information. Happy gardening!