Can You Remake Runny Jam? Yes, Here's How

New to jam? Start with how to make jam, step by step.

A jar of jam that never firmed up is not a lost cause. As long as it tastes good, you can pour it back in the pan and bring it to a proper set. This is one of the quiet advantages of making your own: mistakes are almost always fixable.

First, find out why it did not set

Before you re-cook, read why jam does not set so you correct the actual problem. Nine times out of ten it is temperature, sometimes it is pectin or acid. Knowing which one tells you what to add on the second pass.

The re-cook method

1. Empty the soft jam back into a wide, heavy pan. Work in batches of no more than four cups at a time so it cooks evenly.
2. For every four cups of jam, add one tablespoon of lemon juice. If the fruit was low in pectin, add a little powdered pectin as well, following the package amount for that volume.
3. Bring it back to a full rolling boil and cook to 220°F / 104°C, or until it passes the cold-plate wrinkle test.
4. Fill warm, clean jars, wipe the rims, seal hand-tight, and invert briefly, exactly as you did the first time. See the step-by-step method for the fill and seal.

Use fresh, warm jars for the re-fill rather than the ones the soft jam has been sitting in. Our reusable Jam Jars make this painless: warm a fresh set, refill, and you are done.