There are three main ways to preserve fruits and vegetables: freezing, drying and canning. Of the three, freezing is the easiest, but it takes a lot of freezer space. Drying takes less storage space, and as long as the dried foods are kept dry, they won’t spoil. Canning takes more work than the other two types of preserving, but it can be fun and yield rewarding results.
There are three basic guidelines for any type of preservation. First, produce should be fully ripe, but not overripe, and the best quality available. Second, anything used in the process that will come into contact with the food should be clean. And third, don’t change recipes — the safety of the end product can be affected.
As this column appears to have developed into groups of threes, let me give you three pointers for each of the types of preserving.
Freezing fruits and vegetables
When freezing produce, use moisture-proof containers with tight seals. Either rigid containers or heavy-duty plastic bags made for freezing can be used, as long as the seals are tight. If you are using plastic bags, be sure to press out as much air as possible before sealing.
Liquids and foods prepared in sauce will expand when freezing. Leave about 1 inch of head space in rigid containers.
Finally, be practical about the amounts you freeze. Each container should hold the quantity you will use at one time once defrosted.
Be sure to follow the directions that come with a food dehydrator if you use this method to dry food. If you use a convection oven, set it at 140 degrees or lower, if possible, and leave the door ajar.
When the outdoor temperature is over 85 degrees, it is possible to dehydrate fruit outside (vegetables are not recommended), but plan to bring the drying trays inside at night.
Fruit that browns when exposed to air needs to be pretreated with ascorbic acid. Ascorbic acid should be available in either tablet or powdered form in grocery stores.
Dehydrated fruit stored in airtight containers in a cool, dry space will be good for up to a year. Although it may remain safe to use after that, the quality will decline.
Canning the harvest
Depending on the type of food being preserved, there are two methods of canning: water-bath and pressure canning. Check the requirements for the food you are preserving and be sure to use the correct method to ensure food safety.
When canning, use only jars made for home canning to avoid breakage.
After the jars are filled and before the lids are added, wipe the mouth of the jar with a clean, damp cloth to remove any spilled food or liquid which might prevent a tight seal.
The information provided here is minimal. No matter which method you choose, the most important thing is to use reliable, complete and current information. The University of California has a food preservation website that links to valuable information from many sites across the country. It is well worth the time to investigate the site before starting on your journey to preserve summer’s bounty.
• The Green Thumb is a column by Tracy’s master gardeners. University of California certified master gardeners are available to answer gardening questions from 9 a.m. to noon Tuesdays, Wednesdays, and Thursdays at 953-6112 or email@example.com.