Another week of raspberry jam tests. (Thank god my father sent me a giant box of english muffins over the holidays!) This time, I compared seven raspberry jam recipes that used commercial pectin (five liquid, two powder) from six different recipe books. The ratio of fruit to sugar ranged from 2 (Wild Jams) to 0.5 (Well-Preserved).

I chose three jams to make:
#1 — liquid pectin, fruit to sugar ratio of 2, no added acid
#2 — liquid pectin, fruit to sugar ratio of 1, added acid
#3 — powdered pectin, fruit to sugar ratio of 0.7, added acid

And, the results are…

1) I don’t know what kind of raspberries the Wild Jams folks use, but a fruit to sugar ratio of 2 does not work. It makes raspberry syrup. After waiting 24 hours without a set, I emptied the jars, added sugar to achieve a ratio of 1, added some lemon juice, and boiled it all for 4 minutes. This achieved a perfect set. (and I saved a jar of the syrup to eat over vanilla ice cream!)

2) I can’t figure out why all the liquid pectin recipes say to boil for one minute. I found that I need to boil for 3-4 minutes or the jam doesn’t set. Batch #2 had to be emptied 24 hours later and boiled for 3 mins. After processing, and waiting 24 hours, I achieved a good set. Unlike powdered or homemade pectin, the liquid pectin jams seem to take longer to set. I was convinced I had 5 more jars of syrup until the next day.

3) Powdered pectin makes a lot more foam. See the jars to the left. I should have skimmed the foam before I canned the jam.

4) The more the jam is boiled, the darker it becomes. I noticed significant differences in batches that were re-boiled.

I have a pound of Pomona’s Pectin on the way — this is the pectin that uses calcium to set instead of sugar and acid. So, you can use as much or as little sugar as you’d like. Sounds fabulous to me.