Making A Yeast Starter

yeast_safale_s04When making beer it is imperative to get the fermentation started as soon as possible. We want to ensure an adequate amount of yeast is pitched to get the beer fermenting straight away and also to form a protection against infection from bacteria.

The sachets and tubes of yeast that are supplied from the home brew shop are a long way short of what is required, a lot of time to begin with will be the yeast cells reproducing to an adequate quantity to ferment the whole batch of beer. This is fine of course and I have pitched yeast straight from the packet but there was a noticeable lag in the time it took to begin fermenting.

Commercially, yeast will be pitched at a rate far higher than what is available to buy in either liquid or dry forms. If you are making a higher gravity beer it may be necessary to make a starter so here is a basic guide to how to go about it.

Things you will need:

Glass Jug or Jar
Dry Malt Extract
Sauce pan and lid
Yeast
Thermometer
Sanitiser

 

  1. Put 4 tablespoons full of dry malt extract into the pan and add 2 pints of water. It is important that not to much dry malt extract is added as when the starter starts to ferment it will produce alcohol. If the levels of alcohol are too high it will become toxic to the yeast cells.
  2. Bring the mixture to the boil. Whilst the is happening make sure your glass container and thermometer are completely sanitised using your preferred sanitiser, this is imperative.
  3. After boiling the malt extract and water for around 10 minutes this will also be sterile allow to cool to room temperature with the lid on. It may be a good idea to use a cold water batch for this to get it cool quickly.
  4. Pour the malt extract solution (wort effectively) into the sterilised container and check it is at room temperature with a sterilised thermometer.
  5. Pitch the yeast. If this is liquid straight from the vial. If dried it should be re-hydrated according to the packet instructions.
  6. Cover the container with a sterilised piece of foil and shake vigorously to get as much oxygen as possible into the wort. You can shake every so often for the next 24 hours whilst the yeast reproduces.

It may not seem to be doing anything for a while but eventually you will see some signs of activity and a layer of yeast will form at the bottom of the container in a whitish layer.


It is a good idea to do this a couple of days before hand so you can ensure the maximum amount of yeast cell reproduction. When you are ready to pitch you can swirl the yeast back into suspension and add the whole lot or decant off a proportion of the starter without disturbing the yeast then swirl and pitch to the wort.