The best food preservation methods for fresh vegetables depends on their degree of ripeness. To preserve the best quality vegetables, it helps to understand the difference between maturity and ripeness. Maturity means the produce will ripen and become ready to eat after you pick it. Ripeness occurs when the color, flavor, and texture is fully developed. Once it is fully ripe, fresh produce begins the inevitable and declining spoilage process. Here’s a guideline:
- Mature, slightly underripe produce is optimal for canning and pickling.
- Ripe produce is best for fresh eating, drying, and freezing.
- Overripe produce is suitable for cooking and freezing; cook vegetables into soup or stew.
- Moldy or decaying produce belongs in the composter or worm bin!
To prepare fresh vegetables for preserving, always wash in plenty of running water, remove non-edible parts such as stems and seeds, peel or trim as desired, and cut into slices or cubes. Here are several vegetable preserving methods, from the easiest (and least expensive) to the most complicated.
Refrigerator pickles are the simplest way you can preserve fresh vegetables and extend their shelf life for a few days. Think of them as a type of salad, or simply crunchy, mouthwatering fast food. These easy refrigerator pickle recipes use several types of vegetables and even some fruits.
Salting is an easy and old-fashioned method for preserving vegetables such as salted cauliflower. Salting was promoted in the early twentieth century as an alternative to canning. Many people familiar with the technique consider salted vegetables to be far superior in taste and texture than canned or frozen ones. You must store salted vegetables in a refrigerator (<40°F) or cold cellar where temperatures never go above 50°F. Before using salted vegetables, you usually remove excess salt by soaking in cold water for 2 to 8 hours. You can prepare and serve salted vegetables in the same ways you would as if they were fresh, cold in salads, simmered in soups, or prepared as a hot vegetable side dish.
Fermenting with salt uses low salt concentration (2½% to 5% weight of the salt per weight of the food), to promote fermentation. Sauerkraut and kimchi are perhaps the most well-known examples. But the technique can be applied to almost any vegetable. This recipe for sour turnips is well known in eastern Europe as kisla repa or sauer ruben.
Drying vegetables is easy to do in your conventional gas or electric oven. Electric food dehydrator appliances offer more control than your oven. You can purchase a basic model for as little as $50. One of the best ways to use dried vegetables is this versatile recipe for bean and pasta soup.
Freezing vegetables for long term storage requires adequate packaging and a dedicated freezer appliance (known as a deep freeze) to chill foods to at least 0°F. True freezing is not possible in the freezer compartment of your refrigerator where the temperature typically hovers near 32°F. Treat your refrigerator-freezer like a checking account. Use it for short term freezing of food that you plan to use within one month. To use freezing as an effective food preservation method, routinely clean out your freezer by consuming the food.
Canning requires a modest investment in equipment and skills that are easy to learn and practice. The fundamental tasks include choosing the right canning method, taking precautions to prevent botulism poisoning, and preparing and processing canned foods correctly. There are two canning methods: boiling water–bath (BWB) canning and steam-pressure canning. Which method you use depends on whether the food you plan to can is high acid or low acid. High-acid foods include most fruits and fruit products. In addition, low acid vegetables can be canned using tested recipes for pickles, relish, and tomato products, which contain added acid, usually vinegar.
Pressure canning low-acid foods such as plain vegetables requires a pressure canner. A pressure canner reaches 240°F, which destroys heat-resistant organisms that can cause food poisoning, primarily botulism. Contrary to what some cooks believe, you cannot safely put any food in a jar and process in a canner. To make foods safely, such as canned soups and spaghetti sauce (with or without meat), be sure to use a tested recipe and prepare and process canned foods correctly. Free, tested canning recipes are found online at the National Center for Home Food Preservation, or by downloading the free booklet USDA Complete Guide to Home Canning, 2009 revision.
For detailed information about these food preservation methods, including over 300 delicious recipes, get the book The Home Preserving Bible by Carole Cancler.