This post explains how I extract the pulp from barberries to make jam. See my earlier posts on growing and harvesting barberries and processing the raw berries. I canned the jam just the way I canned apricot jam recently; see that pot for more detailed canning information and links to other jam/jelly/fruit butter posts of mine.
Last year I canned barberry juice. I still have some left so I decided to process all the berries into jam this year. Barberries are naturally high in acid and pectin, so they do not need added pectin to make jam and jelly if you make full sugar jam. However, I used Pomona’s Universal Pectin®, mostly because added pectin cuts down the cooking time to almost nothing. Too much cooking destroys phytonutrients like the purple anthocyanin pigments and vitamin C and alters the flavor; full sugar jams require considerable boiling down time.
I have a hand crank Victorio-style food strainer. However, it cannot accommodate barberries’ large seeds, unfortunately. This has nothing to do with the screen hole sizes, but with the space provided for the seeds to pass through the strainer. Food mills are generally designed to handle tomatoes and raspberry/blackberry-type seeds. The smaller hand crank food mills with a single bowl space do not press out as much pulp as I would like for making jam, either.
Instead, I use a chinois strainer (shin’-wah) with a conical shape and holes very similar to the holes in food strainers. It’s the most old fashioned way to strain pulp from fruit. I placed the chinois over my canning pot. After mashing the cooked barberries with a bean/potato masher I used a spatula to squash the pulp against the sides of the strainer to force the pureed pulp through the holes. This takes muscle power. Dan helped near the end when my arms were getting tired. Periodically I washed off the spatula and used it to scrape pulp off the outside of the strainer into the pot. I had nearly a gallon of pulp and juice when I was done (pictured in the white plastic 1 gallon bucket).
I poured the pulp/juice into my largest bowl and added six cups of sugar to make up for the fact that these berries have no natural sugars. I stirred the sugar into the jam until I no longer felt any grittiness, indicating that the sugar was fully dissolved: 12 1/2 cups pulp/juice + 6 cups sugar added up to 16 1/4 cups because the dissolved sugar molecules positioned themselves in between water molecules in such a way that they take up less room than a non-dissolved substance would take up.
I divided the mixture into three small batches as jam and jelly gel better in small batches (no more than 6 cups of jam before adding the sugar/pectin mixture if you are adding pectin). I like using half pint (cup size) jars for canning jam. However, I also plan to give some of this jam away as gifts, including to my three neighbors whose barberries I picked in addition to my own, so I canned 11 half-cup jars. These tiny jars are canned in two layers. The three bottom photos show the first layer of jars, a second canning rack laid on top of the jars and the second layer of jars on top. I had a little less than 1/2 cup jam left over; I decided to refrigerate it.
The original 8 lb, 13 oz of whole berries (3.54 kg) / 7 1/3 quarts (6.9 L) mixed with evaporated cane juice (unbleached sugar) made 20 cups of jam.
- Picking the berries: 3 hours
- Sorting the berries: 4 hours
- Washing the berries: 1 hour
- Cooking the berries: 45 minutes + 1 hour cool down time
- Extracting the pulp: 4+ hours
- Canning the jam: 4 hours