Preserving Raspberries and Blackberries

Raspberries and blackberries are known as bramble berries, which describes the growing pattern of tangled thorny branches. Raspberries and blackberries have a high water content. This means they will be very solid when frozen. Cell walls of the fruit are punctured by the ice crystals in the cell during freezing. When the fruit thaws, the liquid in the cells escapes, leaving mostly juice and very little solids.

A pie made from bramble berries is very juicy. In order to make a pie from frozen berries, it will be necessary to add a thickener such as arrowroot, tapioca starch, ThermFlo®, or Instant ClearJel® to the berries and sugar before baking it.

Freezing

Raspberries and blackberries can be frozen using the sugar pack method or syrup pack method. Berries may be tray packed without sugar. Keep in mind that these will be mushy when thawed; use partially thawed or use where a puree is desirable, as in a slushie. 

Canning

Because of the very delicate nature of the berry, canned raspberries and blackberries will be very fluid.

Jams and Jellies

Raspberry and blackberry jams can be made using commercial pectin or by the long cooking method. The variety of pectin products available today allows you to make jams of differing sweetness and consistency. All work well when directions are followed exactly. Do not substitute one type of pectin for another. Uncooked jam is another name for freezer jam or instant jam. Recipe inserts that come with commercial pectin contain good recipes for berry jams. If your blackberries are very seedy, you can put part or all of them through a sieve or food mill before crushing them for jam.

Recipes to Enjoy

Blackberry Jam with powdered pectin

Uncooked Berry Jam with powdered pectin

Blackberry Jelly with liquid pectin

References

1. National Center for Home Food Preservation. (2014). Freezing: Raspberries. University of Georgia.
2. National Center for Home Food Preservation. (2014). Freezing: Blackberries or Dewberries. University of Georgia.
3. National Center for Home Food Preservation. (2020). Selecting, Preparing, and Canning Fruit: Berries-Whole. University of Georgia.
4. National Center for Home Food Preservation. (2005). Making Jams and Jellies: Blackberry Jam. University of Georgia.
5. National Center for Home Food Preservation. (2005). Making Jams and Jellies: Uncooked Berry Jam. University of Georgia.
6. National Center for Home Food Preservation. (2005). Making Jams and Jellies: Blackberry Jelly. University of Georgia.