How to rehydrate homebrew yeast

Why rehydrate?

Before you add your dried homebrewing yeast to your wort, you need to rehydrate it with water that has been boiled and cooled.

This will test the yeast’s viability and increase its performance.

If you add dried yeast directly to your wort, up to half of viable cells can be destroyed.

As the sugary wort solution moves into the dry cell it damages the cell wall.

Steps to rehydrate homebrew yeast

Tip in the yeast into water boiled and cooled to 30°C (ales) or 23°C (lagers).

Tip in the yeast into water boiled and cooled to 30°C (ales) or 23°C (lagers).

To rehydrate dried yeast, you need to follow a few simple steps:

Wait 15 minutes and swirl to stir the yeast in.

Wait 15 minutes and swirl to stir the yeast in.

  • Boil your kettle and let it cool to lukewarm. For ales this is 95-105°F (35-40°C). For lager yeast aim for 68-77°F (20-25°C).

  • Clean and sanitize a packet of dried yeast, drinking glass, thermometer and scissors.

  • Pour a cup of pre-boiled water into the glass. Cover with sanitized plastic wrap.

  • Check the temperature and if within the correct range, continue.

  • Wearing your sanitized brewing gloves, cut the top off the yeast package.

  • Tip into the glass and cover again with plastic wrap.

  • Leave for 15 minutes and swirl around to mix in.

  • Leave for a further 15 minutes. You will see the yeast has developed a creamy head.

  • Pitch your yeast into your wort.

Rehydrated yeast showing a thick, creamy head.

Rehydrated yeast showing a thick, creamy head.

Not what you get?

If your yeast does not produce the above results it may be old and unviable. Not good for brewing awesome beer.

If you have a spare 11g packet, use this instead.

As a last resort, use the original packet that came with the kit.

Homebrewing With Kits—The Beginner’s Guide

To help you master homebrewing with kits, I’ve put together a guide based on my experiences over the last two decades.

This is the information I wish I had when I started brewing. I hope it helps you make awesome homebrew.

Download your copy today.