Seed Saving:
Seeds left over from the previous year may or may not be satisfactory for planting, depending on the kind of seed (see Table) and how it was stored. Most unused seed should be stored cool and dry. Be sure to label each container with the variety, the date, and any other pertinent information. Glass canning jar or plastic freezer bags, in the freezer or refrigerator, work well for storage. Once the seed has been stored, avoid opening the container until you are ready to plant; moisture will condense inside the cold jar and dampen the seeds if opened often.
Seed produced from the current year's garden is generally saved only from open-pollinated, non-hybrid plants. Seed saved from a hybrid is likely to revert back to characteristics of previous generations and may not exhibit the desirable characteristics that we want. Generally seed is saved from annual and biennial plants, since perennials are usually propagated through division or cuttings.
The easiest vegetables and flowers to save seed from (good choices for beginning seed savers) are self-pollinating annuals, which include beans, lettuce, marigolds, sunflowers, peas, peppers and tomatoes.
Seed must be mature before it is gathered and thoroughly dried before it is stored. Dry seed as quickly as possible but the TEMPERATURE MUST NOT GO OVER 96 F0! Do not dry in direct sun. The top of refrigerator is warm and has a lot of air circulation.
Use dry processing for plants that produce dry pods. Allow seed pods to dry thoroughly. Thresh to break seed from coverings by rubbing, beating or flailing. Winnowing separates debris and chaff from seed and can include screening, reverse screening and gravity separation.
Wet processing must be used for seeds from fleshy fruit. Remove seeds from mature “fruit” by fermentation if needed (i.e. Tomato). During fermentation bacteria and yeast destroy many seed-borne diseases and removes the gelatinous sack around seeds. Wash seeds with water. Pour off debris and hollow seeds from the top of container. Pour into a strainer and wash under running water. Be sure small seeds can not pass through strainer. Dump seeds onto a glass, ceramic or metal sheet. Do not dry on paper, cloth or non-rigid plastic (seeds will stick to these).
Source: Coffin, D., Saving Seeds, 2007.