Activator Instructions for Homebrewing

Keep refrigerated. This yeast is fresh.

Wyeast is a home-brewed, family-owned business located in the heart of Oregon’s scenic Columbia River Gorge. Established in 1986, our mission is to inspire homebrewers by providing fresh, pure, pitchable liquid yeast.

Our one-of-a-kind activation system “proofs” the yeast and shortens lag time. When smacked, the activation aid releases fermentables and revitalizes the cells. This creates CO₂ and swells the package. The active yeast is now ready to use!

This is based on your beer style, pitch temperature, and fermentation temperature. Learn more about Pitch Rates.

for Ales

Pitch additional yeast when using 1388 Belgian Strong Ale or 3724 Belgian Saison to avoid stuck fermentations.
for Lagers: Pitch warm, Ferment cool
for Lagers: Pitch cool, Ferment cool

Learn more about Lager Brewing and why more yeast is essential when pitching cool.

GET READY

Remove from refrigeration. Allow package to come to room temperature (70 °F or 21 °C) at the beginning of brew day.

ACTIVATE

Move the activation sachet to a corner. On a flat surface, hold sachet in place with one hand and firmly smack with the other. Confirm sachet is broken. Shake package vigorously. Activation has begun!

SWELL

Allow the package to swell for 3-5 hours at 70 °F (21 °C). The yeast will consume the activation contents, which revitalizes the cells and creates CO₂.

Packages close to the Best By date and packages that have experienced temperature fluctuation require more time to swell. We suggest activating the day before or making a starter to ensure yeast activity in these situations. If no swelling occurs, do not use the yeast. Use a fresh Activator instead.

PITCH

Sanitize package, shake vigorously again, then pour contents into 5 gallons (19 L) of well-aerated or oxygenated wort at 65-72 °F (18-22 °C).

WAIT

Maintain temperature until fermentation activity begins (active airlock and bubbles forming in the wort).

FERMENT

Adjust to the desired temperature for the strain and let the yeast do the rest!

Adjust your fermenter to your desired temperature for the yeast strain. Fermentation temperature influences the activity of the yeast and characteristics produced during the fermentation process. Learn more about Temperature.

Ale Yeast Fermentation Temperatures
Lager Yeast Fermentation Temperatures
Belgian & Wheat Yeast Fermentation Temperatures

Product Description

A liquid suspension of Premium Liquid Yeast grown in a sterile, nutrient-enriched malt-based medium and packaged with an inner “activation aid” sachet of liquid fermentables.

Wyeast’s Premium Liquid Yeast for Homebrewing includes Saccharomyces cerevisiae, Saccharomyces pastorianus, Saccharomyces cerevisiae var. diastaticus, and blends of Saccharomyces species. Products containing S. cer. var. diastaticus are identified on the front of the package with “STA1 +”, the signature gene of diastatic yeast.

Sterile Packaged
UV Light Barrier
Keep Refrigerated
Do Not Freeze

Best By Date

The Activator System performs best when used by the Best By date when stored between 34-40 °F (1-4 °C) and used following the instructions here. We calculate our Best By date according to the true age of the yeast as determined by our microbiologists, and not simply by the date the yeast was packaged. This method provides consistent, reliable Best By dates and a minimum of 6 months of shelf life under our product warranty.

Packages close to the Best By date and packages that have experienced temperature fluctuation require more time to swell. We suggest activating the day before or making a starter to ensure yeast activity in these situations. If no swelling occurs, do not use the yeast. Use a fresh Activator instead.

Make a starter or pitch more yeast if the package is within 60 days of the Best By date.

Product Integrity & Viability Calculators

The best way to determine the integrity of your Activator is to activate it! Using third party pitch rate calculators do not reflect the true yeast health and viability stability of our products and will often recommend pitching too much yeast.

Product Warranty

We guarantee the integrity of our yeast & cultures for a minimum of 6 months, assuming they have been properly shipped, stored, and handled. Our packaging material provides 100% oxygen barrier and UV light protection making this guarantee possible. During the guaranteed shelf life, some loss of viability is to be expected. This will vary from one strain to another. However, the rate of viability loss is significantly less than many outside sources claim.

Activator packages will sometimes swell slightly during shipping, or later while properly stored. This is not an indication of deterioration if the package is within the Best By date. This is due to trace amounts of residual fermentables at the time of packaging being consumed by very active yeast. The cells produce some CO₂ during this process, also known as “off gassing”, and cause the package to swell. Some strains are more prone to this than others. As long as the inner activation aid can be located and positioned in a corner to activate, the product can be used as normal.

Intended Use

This product is designed and intended for home-scale fermentations and is not warranted for the use in commercial application beyond pilot testing. This product is not for propagation or remanufacturing.