No, I don’t have that book. I don’t make a lot of jam in general. If I make fruits preserves, my first choice is drying them. Second choice is making wine ( not I drink a lot of wine， I just enjoy experimenting, or give out as a gift). But I will look into the method you suggested. After all food safety is the most important thing
I like making jams but I also like just making simple fruit syrups for waffle/pancake toppings. For example, just heat some gooseberries with the tiniest bit of water in a pan and add sugar to taste. It will keep in the fridge for a few weeks.
It really changed the game. Check out the article I link above. Be they did a good job explaining the concepts, then walk you through a specific example of applying them. They link to the specific recipe if you want to really follow along.
@KSprairie, yeah I like the soft set jam, too. Added pectin does usually lead to a stiffer jam/jelly for those that prefer it. I have to try very hard with grapes to keep it from getting firmer than I like, because they have so much pectin.
I had around 4 gallons of gooseberries last year and processed most into jam. How I do gooseberries (and currants), is put them in a pot, stems, blossoms ends, etc. and add a little bit if water so they don’t burn. Summer for a bit, and go at them with a potato masher until they are all soft and mashed. I then put them through a food mill to remove skins, stems, seeds and most blossoms ends. If you want really clean jam, you can put it through a fine metal seive.
I then measure the amount of pulp and while heating I add the sugar. I usually start with a 1:0.5 pulp:sugar ratio and taste once dissolved. Depending on the tartness/sweetness at this point I’ll add more sugar if needed. Last year I was at a 1:0.75 pulp:sugar ratio for my gooseberry jam. Then I cook until it is set as determined by the freezer plate test. The more sugar you add the less time it will take to set.
From last year
I have a number of gooseberries with uneven ripening and I pick them all at once ripe or not. This results in a really nice jam. Much more flavour than I would expect the fully ripe berries to give and I like the tart sweet balance. Just off the top of my head a particular favorite variety for this is Blue Velvet (maybe the name is black velvet). Not sure. And less ripe fruit has more pectin. I just decide on a fruit to sugar ratio add lemon juice then cook and stir till it looks like it will set.
Last year my daughter made a jam with half gooseberries (poorman) and half raspberries (prelude) using about half the sugar suggested by most recipes. It was one of the best I’ve ever had, just barely behind black currant jam which is my all time favorite.