Found this great comic style pictorial on HomebrewTalk on making a yeast starter, very simple step by step instructions.
Yes it’s that simple folks, just in case you need more clarification see the steps below:
- Add 10g of DME (Dry Malt Extract) for every 100ml of water. A typical starter is around 1 liter.
- Boil the DME and Water solutions for a few minutes.
- Chill the the now wort to 20C by placing it in an ice or water bath.
- Shake the cooled down wort to aerate it, boiling takes oxygen out of the solution and yeast need oxygen to multiply.
- Pitch your vial of yeast into the aerated wort.
- Cover it with sanitized foil and optionally place it on a stir plate and let it ferment for a minimum of 24 hours.