Yeast, when purchased from a homebrew supply store, comes in two forms: Liquid and Dry. What are the pros and cons of each and how are they used when making beer?
Liquid Yeast
Liquid yeasts typically come in either pouches or in tubes. Some of the manufactures of liquid strains are Omega Yeast, Wyeast Laboratories, and White Labs.
Advantages of Liquid Yeast:
- Strain Variety
- Freshness of flavor imparted by yeast
- Can grow up to the desired pitching rate
Disadvantages:
- Sensitive to mishandling (including being exposed to freezing temperatures or hot summer temperatures)
- Higher risk of introducing infection
- Typically have to grow to achieve desired pitch volume
- Cost (A 125g liquid American Ale yeast for example costs ~$11.00 at time of writing)
- Wort requires oxygenation to ensure healthy yeast fermentation
Important Points
When purchasing liquid yeast in person, choose packages that are less than three months old. The older the package is, the less viable the yeast becomes which boosts infection risk, can cause stress induced off-flavors, and can impact attenuation.
A viable culture can be regrown from one- to two-year old packs following special starter instructions so not all is lost if the package is dated.
Always take care when pitching yeast, to sanitize everything that will touch the yeast slurry or its packaging before opening.
Dry Yeast
At a homebrew level, dry yeasts will come in sachets, typically around 11g. Some of the manufacturers of dry yeast are Fermentis (SafAle/SafLager) and Lallemand.
Advantages of Dry Yeast:
- Cost (An 11g sachet of dry American Ale yeast for example costs ~$6.50 at time of writing)
- The yeast concentration is significantly higher allowing for less added volume from yeast pitching.
- Longer shelf life.
- Ease of use. Just re-hydrate if desired and pitch into the beer. Beer doesn’t need to be oxygenated.
Disadvantages:
The main disadvantage to dry yeast is that there are fewer options available. As time goes on however, yeast manufactures have found more strains that are tolerant to the drying process, increasing options in the market.
Important Points
Re-hydration gives the cell walls time to strengthen before hitting the sugar rich wort. To hydrate the dry yeast, if desired, boil a cup of water with an optional pinch of yeast nutrients for 5 minutes. Cover with foil and cool to around 100 degrees F. Sanitize the dry yeast packet and cut it open with sanitized scissors. Pour the yeast into the warm water and gently swirl. Let sit covered for 5 to 15 minutes before adding small portions of wort to the yeast mixture to bring the temperature down to the temperature of the wort. Refer to the suppliers datasheet on the yeast for the recommended rate to cool the yeast slurry. Don’t wait longer than 15 minutes to start adding wort to the yeast slurry and pitch as soon as the desired temperature is achieved as the yeast is burning through its energy reserves while in pure water.
There is debate on whether rehydration is required before pitching. Some manufactures even recommend pitching the yeast dry, but do still provide rehydration instructions if desired. Proponents to yeast rehydration state that a significant percentage of the yeast cells die upon pitching the dry yeast into the wort. Opponents state that rehydration increases the risk of introducing an infection. I typically only rehydrate yeast when its going to have to work hard on big beers of 6% ABV or higher, otherwise I just pitch dry.
Conclusion
For a new brewer, I would recommend sticking with dry yeast while figuring out the brewing process. It is easier to handle and is a cheaper option.
No matter which option you choose, I recommend keeping a spare dry yeast sachet such as an American Ale or British Ale strain that can be used as an emergency backup if your initial pitch doesn’t take or there are issues with the yeast starter and you decide you don’t want to attempt to pitch it.
