Yeast "breaths" through a process called anaerobic respiration - in this process, glucose (sugar) is fermented to produce energy, carbon dioxide, and ethanol (alcohol)
From Dry Beer Yeast:
Pitching more yeast will result in a shorter lag time between pitching and fermentation, and is sometimes necessary to achieve a full fermentation when making higher gravity beers like barleywines or strong Belgian ales. Here are step by step instructions on how to make a yeast starter:
- Dissolve 1 cup malt extract (or corn-sugar) in 2 cups hot water. Bring to a boil, cover, and simmer 15 minutes to sterilize mixture.
- Cool the mixture by placing the pan in the sink with ice water surrounding it. When sufficiently cooled to approximately 80F, pour into sterilized 2 qt. jar along with the contents of the dry yeast pouch.
- Cover jar immediately with a piece of foil or rubber-banded plastic baggie. Leave at room temperature, swirling periodically. When starter looks foamy (1 to 2 days), brew and continue as usual.
From Wyeast:
Although the Wyeast smack-packs we sell will generally pitch between 45 and 60 million yeast active yeast cells when properly incubated, sometimes making a yeast starter is a good idea. Pitching more yeast will result in a shorter lag time between pitching and fermentation, and is sometimes necessary to achieve a full fermentation when making higher gravity beers like barleywines or strong Belgian ales. Here are step by step instructions on how to make a yeast starter:
- Break the inner seal on the yeast pouch. Let sit at room temperature (75F) until the pouch swells up, about 6 to 24 hours.
- Dissolve 1 cup malt extract in 2 cups hot water. Bring to a boil, cover, and simmer 15 minutes to sterilize mixture.
- Cool the malt mixture by placing the pan in the sink with ice water surrounding it. When sufficiently cooled to approximately 80F, pour into sterilized 2 qt. jar along with the contents of the yeast pouch. (You will need to sterilize the corner of the pouch before cutting it open. Remember that there will be some pressure built up in the pouch, so cut into it gently, and have your jar right there).
- Cover jar immediately with a piece of foil or plastic baggie. Leave at room temperature, swirling periodically. When starter looks foamy (1 to 2 days), brew and continue as usual.
Judging a complete fermentation: The qualities of some of the liquid yeasts include the fact that most of them produce a large, rocky head of foam. Some (such as #1007) do not break apart and sink. Regardless, transfer out of primary in 4 to 5 days. The yeast can then be re-used.
To re-use yeast: Transfer the beer out of the primary into the secondary. With a sanitized scoop, add a cup or so of the sediment to a sanitized jar and cover with foil or a plastic baggie. There is now about 100 times more live yeast than what you started with! Store in refrigerator not more than 10 days. Re-feed with malt starter (as in step 2-4) before brewing again.
Questions? Call us! We really think that whether you use a starter or not, you'll love the results of using liquid yeast in brewing.