Freezing Soft Fruit

When the raspberry canes and currant bushes all ripen at once, the freezer buys you time. Spread the fruit on a tray, freeze it hard, then bag it. Each berry stays separate, so you can tip out a handful for porridge or weigh out a batch for jam later in the year.

Why freeze on a tray first

Open-freezing (also called tray freezing) needs no sugar or syrup, which leaves you free to follow a jam recipe's sugar exactly later. Berries packed straight into a bag while soft freeze into one solid lump.

How to open-freeze berries

1. Pick firm, fully ripe fruit and sort out any that are soft, under-ripe, bruised, mouldy or damaged.
2. Prepare each fruit as the table below shows: wash it (except blueberries), drain it well and remove stalks, caps or tails.
3. Spread the berries in a single layer on a baking tray or shallow tin, not touching if you can manage it.
4. Put the tray in the freezer until the fruit is frozen solid. Strawberries take an hour or two.
5. Tip the frozen berries straight into freezer bags or containers. Work quickly so they don't start to thaw.
6. Press as much air as possible out of bags to limit freezer burn. In rigid containers, leave a little space at the top.
7. Label each bag with the fruit and the date, then return it to the freezer.

Keep the freezer at -18°C or colder. Don't load in a whole glut at once: add only as much as will freeze within 24 hours, and leave a little space between packs so cold air can circulate.

Fruit by fruit

Why thawed berries go soft

Water in the fruit expands as it freezes. The ice crystals break the cell walls, and when the fruit thaws the juice runs out, leaving the berry soft. This is why raspberries, blackberries and especially strawberries slump when fully thawed, even though they taste fine. Plan to use them where texture matters less: stewed, baked, blended or boiled into jam. If you want berries to eat with a spoon, serve them only partly thawed.

How long frozen berries keep

UK advice is to use frozen berries within about 3 months for the best quality. They stay safe for longer, provided they stay frozen: US guidance gives 8 to 12 months at -18°C for frozen fruit, and says food kept past that time is still safe, just lower in quality. Flavour and texture slowly decline, so the dated label is worth writing.

Thawing frozen fruit

Thaw berries in the fridge, not on the worktop, and use them within 24 hours of thawing. Cooked berries keep in an airtight container in the fridge for up to 2 days.

For how long jam and chutney keep once they're made, see how long preserves keep. For beans, peas and other vegetables, which usually need blanching first, see freezing and blanching vegetables.

Freezing fruit now for jam later

Unsweetened frozen berries work well for jam. Thaw them completely, crush them if the recipe says to, and then measure the fruit as the recipe asks. Don't pour off the juice that runs out as they thaw: it goes into the pan with the fruit.

Freezing doesn't replace the setting test. Some soft fruit is naturally low in pectin, and pectin levels also change with ripeness (the pectin in fruit guide explains which fruits set easily). Cook the jam as the recipe says and check it with the setting point tests before you pot it. If you plan to make gooseberry jelly, freeze some of the berries while they're still a little under-ripe.

Frozen fruit suits all of these:

• Raspberry jam
• Strawberry jam
• Blackcurrant jam
• Gooseberry jam
• Redcurrant jelly
• Bramble jelly

For other ways to use a heavy crop, see the glut guides for raspberries and blackberries, blackcurrants and redcurrants and gooseberries.

Common questions

Sources