How long does fresh yeast last, and can you freeze it?

Half a packet of yeast is left after the weekend baking, and the same questions come up: how long will it keep, and can you freeze it? Here are the answers, plus a quick test to see whether it is still active.

Storing an opened packet

Yeast is a living fungus and loses activity as it dries. Wrap the rest closely in its original paper plus a beeswax wrap, or use a small container. Keep it in the fridge, preferably towards the back where the temperature is steadier. A dry edge can be trimmed, but discard yeast with mould, an unusual smell or extensive darkening.

Is the yeast still active? Try this test

Stir a teaspoon of yeast and a teaspoon of sugar into 50 ml of lukewarm water, around 37 °C. If it foams within ten minutes, it is active. If nothing happens, use fresh yeast rather than relying on it to raise your dough. The test takes ten minutes and can save a baking day. It checks activity, not the safety of spoiled yeast.

Freezing fresh yeast: yes, with a couple of limits

Divide it into portions of 25 or 50 grams, wrap each closely and freeze for up to 3 months. Thaw in the fridge, not on the counter, and use promptly. Its texture may become soft and pasty even when it still works. Freezing can weaken it, so a little extra yeast or more rising time may be needed; avoid repeated freezing. If you bake rarely, dry yeast in the cupboard is an alternative: unopened packs can keep for around a year, depending on the date and storage instructions.

Yeast or sourdough?

If you bake often, a sourdough starter is a long-term alternative: it needs feeding instead of another shopping trip. See feeding a sourdough starter and yeast bread or sourdough. Whatever raises your dough, the finished bread deserves good storage. A breathable wax-lined bag helps keep it fresh for 7 to 10 days: see how long homemade bread stays fresh.

Frequently asked questions