Recipe This | Instant Pot Strawberry Jam (2024)

FAQs

How do you know when jam is cooked enough? ›

1) The Saucer Test

Once you think that your jam has reached its setting point or has thickened, spoon a bit of the jam on the cold plate and tilt it vertically so the jam runs. You are aiming for a slow descent, not a runny mess. If it runs slow, it's set!

Sugar - Sugar will help sweeten your jam but it also helps thicken it. The sugar binds to the water in the fruit and thickens the liquid. Lemon Juice - Lemon juice is great for flavor because it adds that bright acidic taste to all that sugar but it also helps your jam thicken.

Lemon is crucial to balancing those sweet flavors, but it also helps the pectin to firm up the jam. It can be added at the start of the cooking process or towards the end, but what must be taken into account is that adding liquids to the jam mixture will inevitably require the jam to cook for longer.

Adding acid in the form of fresh lemon or lime juice is important for two reasons: First, it makes for a more well-balanced jam, returning some of the acidity lost with the addition of sugar. Second, pectin needs acid to properly activate, or firm up.

Push your finger through the jam on the plate - you're looking for it to wrinkle and not flood back in to fill the gap. If it's not ready, turn the pan back on, simmer for five minutes and test again.

Spoon all the undercooked jam into a large saucepot. Add about 1 tsp lemon juice for each cup of jam. Bring to a boil and cook until jam sets. Remove from heat and pour into clean jars.

Yes, jam will be quite runny when it's hot, and then will thicken and set as it cools. Sometimes it can take 24-48 hours for the pectin to fully set.

Since pectin is activated by sugar, it requires using a considerable amount of sugar to activate the pectin and set (i.e. thicken) your jam. If you try to cut back on the sugar, it won't set properly.

It's Not Only About Pectin

There's another reason why lemon juice is added to most jam recipes: for safe canning and to prevent the growth of bacteria. Bringing the pH level down means jars can be sealed in a regular boiling water bath in a reasonable amount of time (sometimes as little as 10 minutes).

Cooking any mixture of fruit and sugar long enough will result in a jam that will set up in your canning jars. But longer cooking times can mean over-processed flavor, darkened color and a lower yield. Adding pectin allows you to cook jam for a much shorter time, which may result in the jam of your dreams.

What is a substitute for pectin? ›

Pectin Substitute

Cornstarch - Another plant-based thickening agent, cornstarch is a great substitute for pectin. Gelatin - For non-vegan menu items, you can substitute gelatin for pectin, but it will yield a different consistency.

5. Do Not Stir Once Mixture Is Boiling. Once your jam/marmalade it has reached a rapid rolling boil do not stir it. Stirring it will alter the temperature of the jam/marmalade meaning it will take longer to reach the setting point.

You can use bottled lemon juice or fresh. However, I personally look to use other complementary juices to certain fruit jams. Rather than rely on lemon juice I would for example use redcurrant juice from fresh redcurrants in a strawberry jam instead, or an acidic type of apple and apple juice in a blackberry jam etc.

The amount of sugar you need to make jam depends on the amount of pectin in your chosen fruit, but generally the fruit-to-sugar ratio for traditional jams is 1:1 (ie. 450g/1lb sugar to 450g/1lb fruit).

If the jam runs right off the spoon and looks thin and runny, it's not done yet. However, if it forms thick droplets that hang heavily off the bowl of the utensil, but don't immediately fall off, it is either nearing completion or is done. Use the freezer test.

Setting point is 104.5°C. You can tell when jam is reaching setting point as the fast, frothy rolling boil will reduce to a slower, more relaxed boil. The tiny air bubbles disappear, the surface looks glossy and the mixture will feel thicker. Undercook rather than overcook – runny jam can be cooked up again.

If, on the other hand, the jam is rock solid, that means you've gone too far and cooked it too long. You can try adding a little water to thin it out, but bear in mind that after overcooking a jam, you can't really get those fresh fruit flavors back.

Boil until the jam hits the set point, 220 degrees F on an instant-read or candy thermometer, about 20 minutes. Alternatively, place a dish in the freezer ahead of time; a dollop of jam on the cold plate should wrinkle when you nudge it when it's ready.