Rehydrating Dried Yeast

Why Rehydrate?

Before dry yeast can start fermenting, they need to absorb the water they lost during the drying process.

But Why?

The objective is to reduce the lag phase: the time necessary for the yeasts to start fermenting sugars to alcohol after inoculating the wort.

Temperature of Rehydrating Liquid?

Yeasts are living organisms and rehydration temperature is critical for good yeast performance.

  • Ale Yeast (top fermenting) between 25-29°C
  • Lager Yeast (bottom fermenting) between 21-25°C

How to rehydrate your dried yeast?

Rehydration is done in a different vessel often a glass flask, or something similar

Both water and wort can be used. Completely Your choice.

Make sure your equipment is all sterilized using a trusted brewing steriliser.

Rehydrate the dried yeast in 10 times its weight of water/ wort

With a gentle stir and then a leave yeast for at least 30 minutes

Use immediately if the wort in the fermenting vessel is at desired temperature.


Make sure if your using water - boil the water and allow to cool down.