Last weekend, Carol went strawberry picking and suggested I turn most of the strawberries into preserves. I am still pretty inexperienced in making preserves, and this turned into more of a learning experience than I had expected. In any event, the final product was good, and I will incorporate in this post what I learned. The yield was a little more than 8 half-pint jars.
8 cups of crushed strawberries (in a food processor – about 3.75 lbs.)
1 pouch Ball RealFruit Liquid Pectin (or equivalent)
7 cups sugar
¼ cup lemon juice
Heat the water in a canning pot to at least 180 degrees. Wash the jars and sterilize them in the hot water for at least 10 minutes. Then remove and drain them. Wash and heat the lids to soften the seal and sterilize them. Put a small plate in the freezer.
In a large flat pot, like a Dutch oven, put the strawberries, pectin, and lemon juice. (The reason for the flat pan is to increase the surface area for evaporation of water. (This need for evaporation is one of the reasons why books on preserves recommend not making big batches.) Bring to a boil stirring occasionally. Add the sugar and bring back to a boil. Stir frequently, boiling it until the temperature reaches about 220 degrees. (This took much longer than the instructions I was following.) Further check that the mixture has jelled by putting a small spoonful on the plate from the freezer.
Remove from heat. Stir for a couple of minutes to ensure that the fruit is evenly distributed. Using a canning funnel, fill the jars to within ½ inch of being full. Clean off the rim of the jars with a paper towel. Put a lid on each jar and secure them with a loosely fitted band. (Leave it loose so that when the contents expand, some air will be expelled, so that a vacuum will form when the jars cool.) Allow the jars to fully cool for 24 hours and then test to see if a vacuum seal was formed. If not, store the preserves in the refrigerator or reprocess with a new lid. Label the cooled preserves including the date.
If the mixture does not seem to jell, or if you have put it in the jars but the jars have not jelled, you can reprocess by adding ¼ cup sugar mixed with 1 Tbs. of pectin, and returning it to a boil. It will definitely thicken if heated to around 220, which can only happen if a lot of the water is boiled off.