A yeast starter is a way to drastically increase the number of yeast cells that you will pitch into wort. A starter is essentially a mini fermentation, only you are making yeast not beer. You should use a yeast starter when you need to ferment stronger beers such as Imperial IPA's or Barley Wines, but lagers will need more yeast as well. Any beer will benefit from the use of a starter, and in general terms, more yeast will make cleaner tasting beers that ferment faster. Using a starter is a good idea when using older yeast, or yeast that has been stressed by shipping.

To make a starter for your yeast, you need to make a wort with a gravity of around 1.040. The most common volumes of starters that we recommend are 1/2 and 1 gallon (2000 and 4000 mL). To make the wort for these volumes, follow these recipes: (table of recipes for each volume, with water volume, extract amount, and nutrient amount)

Use the lightest colored malt extract that you can find, so that little to no flavors are transferred to your beer. Don't use hopped extracts to make starters, because the hops can disrupt yeast growth. I recommend that you use a small amount of nutrient in your starter. This is optional, but it will help your yeast ferment your beer later on. Boil the wort for fifteen minutes to sanitize. You can use a small pot on your stove to do this, or you can boil in an Erlenmeyer flask. Never use these flasks on electric ranges or hot plates. They will crack.

If you use an Erlenmeyer Flask, you can cool the wort in an ice bath with out transferring. Alternatively, you can start your yeast using gallon or half-gallon jugs. Be sure to cool the wort before racking into these vessels. Pitch your yeast into your starter vessel. Cover the opening with a sanitized piece of tin foil. The positive pressure created by the active yeast will keep out any unwanted critters. You can also use a foam stopper, but these cost more than tin foil, and can easily harbor beer spoiling bacteria and yeast.

Let your yeast starter sit at room temperature (65-75 F) for two to three days. Gently swirling your starter occasionally will improve results. Using a stir plate will provide you with the best results. Be sure to clean and sanitize the magnetic stir bar that goes inside the starter when using a stir plate. The morning or night before you brew, place your entire starter in a fridge. This will settle out the yeast for you. Before pitching your starter, gently decant, or pour-off, the liquid above the yeast. Leave a small amount, about a cup or so, inside so that you can swirl the starter and rouse the yeast right before you pour it into your fermenter.

If you have any questions about making or using yeast starters, please feel free to call us at 1-800-450-9535, or e-mail us at outpost@homebrewers.com