Yeast Directions for Beer Making

Understanding how to use yeast in brewing will help you produce better beer

Beer requires only four ingredients: Water, malt, hops and yeast. All are equally important, but it is yeast that transforms the others into one of the world's most popular beverages. Because yeast is alive, it must have the right conditions in order to thrive. Nourishment, oxygen and a the right temperature will encourage the yeast culture to multiply and do its job, converting the sugars in the wort into alcohol and carbon dioxide. Using yeast correctly in your home brewing will greatly improve your final product - a beer you can enjoy.

Instructions

1. Select the correct yeast for your beer. The choice will be determined by the type of beer you are making, ale or lager. Ale yeasts are called "top-fermenting" because the yeast tends to float on top of the wort during fermentation. Ale yeasts work best at room temperature. Lager yeasts are "bottom fermenting" as they sink to the bottom of the vessel while working. Lager yeasts work best in cooler temperatures. Within each of the two categories there are many different varieties with different taste characteristics. Follow the directions of your beer recipe to select the proper yeast.

2. Prepare the yeast correctly. Yeast is packaged in several different ways. Dry yeast in packets must be re-hydrated in warm water before using. Liquid yeast may be packaged in an envelope called a "slap pack." An interior chamber must be broken to release the yeast into a nutrient solution to activate for 24 to 48 hours prior to using it. Yeast can also be sold as a liquid in a bottle, ready to be pitched into the wort. Some recipes call for a yeast starter, in which the yeast is dissolved into a malt or sugar solution for a day or more before using. The key is to have as strong and active a yeast solution as possible before pitching it into the wort.

3. Cool the wort to room temperature before pitching the yeast. Boiling hot wort will kill the yeast instantly. Use a wort chiller or an ice bath to bring the wort temperature to between 70 and 75 degrees Fahrenheit before pitching the yeast. Yeast requires oxygen to work; boiling reduces the oxygen content of the wort. Stir or otherwise aerate the wort thoroughly before pitching the yeast. Some brewers even use specialized air pumps, similar to aquarium aerators, to add oxygen to the wort.

4. Follow the directions for temperature control during fermentation. Ale yeasts work best between 68 and 72 degrees Fahrenheit; lager yeasts prefer temperatures of 45 to 50 degrees. In fact, through a process called "lagering," the temperature of lager beer is slowly lowered even more, during the final stages of fermentation to produce a more crisp, refreshing taste to the beer.

Tips & Warnings

• If fermentation fails to start within two days of pitching the yeast, you can attempt to rescue the batch by pitching additional yeast.

References

• How to Brew by John Palmer: Chapter 6 -- Yeast
• Beer Advocate: Yeast Guide
• Brew Your Own: Controlling Fermentation Temperature