I've never had any luck adjusting jam after it's been prepared. You mighty backing up to the step where you added the pectin and continuing from there with more, but be prepared. It's not likely to work out the way you want. (either too soft or too firm)
Pectin. Pectin is a food-gum that comes from fruit that helps thicken jam when sugar is added.
The best method for making freezer jam using pectin is to follow the instructions on the pectin package, which typically involve combining crushed fruit, sugar, and pectin, then letting it set before storing it in the freezer.
To properly store homemade jam in the freezer using pectin, allow the jam to cool completely before transferring it into airtight containers or freezer-safe bags. Leave some space at the top of the container for expansion during freezing. Label the containers with the date and type of jam. Store in the freezer for up to 1 year.
Yes you can recook jam that did not set. Just Google "recooking jam" and you will see a number of Coop. Ext. sites and others that will show you the way. Happy jammin' Thom Foote Fairbanks, Alaska
Jam is whole fruit cooked in sugar until the flesh is soft. Jelly is fruit juice cooked with pectin or gelatin until it congeals.
Pectin should be added to jam at the beginning of the cooking process to help the jam set properly.
PECTIN
The conventional method of making jam and jelly involves cooking fruit with sugar and pectin, which helps to thicken the mixture and preserve it for long-term storage. In contrast, the Freezer method uses fresh fruit, sugar, and pectin but skips the cooking process, allowing the mixture to set in the freezer. This results in a fresher flavor and a more vibrant color, while the texture may be slightly less firm than that of conventionally cooked products. Additionally, freezer jam and jelly can be stored in the freezer for up to a year, while canned versions have a longer shelf life at room temperature.
To make blueberry jam without using pectin, you can cook the blueberries with sugar and lemon juice until the mixture thickens naturally. The natural pectin in the fruit will help the jam set.
sur-gel is a brand name. Pectin is the ingredient. Pectin is the ingredient used in jam making, it helps set the jam.
Rhubarb is low in pectin, jam may not set
You add fruit pectin when canning to your fruit mixture after it has cooked. The pectin will cause the jelly or jam to firm up and you can package it from there.