Putting Food By is a term used to describe preserving food. It can be canning, freezing, dehydrating, smoking etc. Just in case I am very successful at vege gardening, I thought it would be prudent to learn how to 'Put Food By' before the harvest comes in. I bought 'Putting Food By' by Janet Greene and the Ball Blue Book canning book. Between these two books, you can find all the information you need to preserve food.
Darling daughter and I carefully heated the jars and lids, cooked the recipe to Blueberry Jam, filled the jars, wiped the rim, placed the lids, processed in a water canner, and cooled. The gel did set so I do indeed have blueberry jam and not blueberry syrup:)