It hasn't all been cherries around here.
The stone fruit is ripening and really coming into it's own now.
I love Greengage Plums and could eat them until I was sick. Pretty much one has too anyway because they have such a short life-span. Once they are ripe they can be past it within 24-48hrs so you do have to be quick. That is also why they are rarely on market shelves as they don't travel very well so it is really handy to know people in your neighborhood with trees.
One of the important rules of jam making is to cook the fruit slowly on low heat thus releasing the pectin that will help the jam set and then rapidly on a higher heat after the sugar is added.
I still prefer the old fashioned way of boiling the jars and lids for 10 mins to sterilize and then placing them upside down in a warm oven. Once the jam is at set I then bottle it hot into the hot jars sealing immediately.
The pectin in the fruit is key to getting jam to set and plums have plenty. I test for set on a cold plate.
In this picture there is a very light coloured blob on the left that I tested after about 10 mins of rapid boil. You can see how thin the mixture is and that it doesn't hold a shape but spreads readily. The blob at the top was after another 10 mins of rapid boil. Once cooled this test patch though thicker than the first still runs fairly freely. If I push the jam with my finger the jam quickly flows back into the trail I've made.
The last test blob is noticeably darker and thicker and once cooled I can push the edge with my finger and see the surface kind of wrinkle like tight surface tension. Another way to test for set is by checking the temperature which will reach 104C or 220F. The Vacola bottling thermometer comes in handy again!
So the basic recipe I used.....
3kg of Greengage plums
1 1/2 cups of water
1/3 cup of lemon juice
3kg of sugar
1/2 cup chopped preserved ginger
Cook the fruit gently in the water until softened.
Add the sugar, lemon juice, ginger and some of the rind from the lemons if you like.
Stir till thoroughly dissolved and increase the temperature to a gentle boil.
Keep checking for set and don't let your jam burn on the bottom, that is an awful mess to clean (not to mention it taints the whole batch)
Had I had Green Ginger Wine on hand I think I would have used that instead of water to poach the fruit.
I think whiskey would also go well with this jam.
This makes a very respectable amount of jam which I like as there is plenty for the shelf and some for giving.