While any beer will benefit from the use of a yeast starter, one should definitely be used if you're brewing a high gravity beer, such as a Barley Wine or an Imperial Stout. A yeast starter will result in a quicker start to fermentation, and a more complete fermentation.

How to prepare a yeast starter:
  • If you have an Activator yeast pack, activate it 24-72 hours in advance. If you're using White Labs, remove it from the refrigerator 2-4 hours in advance.
  • Mix 16 ounces of water and 1/3 to 1/2 cup of dry malt extract together and bring to a boil for 15 minutes. If you are using a flask it can be heated directly on an electric or gas burner.
  • Cool this mix to below 80°F (an ice bath will work for this small amount) and then add the yeast.
  • Frequently aerate the mix to help aid in yeast production. This can be done by shaking the flask. A healthy froth on the yeast starter should develop after 1-3 days.
  • At this point, the yeast is ready to be pitched (added to the wort).
  • Add the yeast starter to your beer/wort after it has been cooled below 80° F. If you re making an ale, ferment at recommended ale temperatures. If you are making a lager, wait for fermentation to start and then reduce the fermenter's temperature to the recommended lager fermentation temperature,
  • Signs of fermentation should be evident within 24 hours, depending on yeast strain, brewing procedures and fermentation temperatures.

You can use a larger beer bottle as well, but make sure that you have a stopper and airlock that will fit the bottle first. Also, you cannot heat a beer bottle directly on your stove. Only flasks can handle the higher temperatures.

If you are planning on doing a high gravity/alcohol beer, you can make a larger starter by keeping the 2:1 ratio in mind. You can mix 32 ounces of water with 1 cup of dry malt, for example. Larger starters will allow more yeast cells to form, which in turn will allow you to have more yeast to eat all your sugar.