Boulder Blend

A Beer for Boulder

A collaborative effort to raise money for those affected by the Boulder King Soopers mass shooting on March 22, 2021. 

In 2016, Cellar West owner/brewer Zach Nichols isolated a blend of native yeast (Brettanomyces & Saccharomyces) and bacteria from the air surrounding our Boulder brewery - a blend of wild microflora specific to Boulder. We've featured this special blend in many of our beers since then, including award winning mixed-culture Saisons like Westfield & Make Hay.

We've made our "Boulder Blend" available for the first time, in an effort to raise funds for those affected by the tragedy in Boulder.

We're asking that participating breweries do the following:

- Craft a beer using the Boulder Blend

- Make note of the Boulder Blend and fundraising efforts on marketing materials related to the beer

- Donate 100% of proceeds from beer utilizing the Boulder Blend to the Colorado Healing Fund for Boulder King Soopers Tragedy


Pitches of the Boulder Blend (any size) are available for purchase from Brewing Science Institute, who is taking 25% off the regular price for the blend. Please allow up to 10 days for propagation. This blend is affective and produces great beer for either full primary fermentation, or as a later addition in secondary aging, and creates notes of dried apricot, citrus zest, roses, spiced pear, funky farmland air, and white peppercorn.

This effort allows the Boulder Blend to be used in any beer, of any scale, so long as those agreements are fulfilled. Zach has put together a Boulder Blend Saison recipe for breweries interested in building a collaborative beer from the ground up - this recipe can be found below.

Lastly, we've created a "Boulder Blend" seal which brewers may use on relevant labels & marketing material.

Thanks for your consideration in this endeavor. For additional questions on the Boulder Blend efforts, the blend itself, or the Saison recipe, please contact

- The Cellar West Team

Boulder Blend Saison

This recipe is for a 7bbl batch with 70% mash efficiency - please modify to fit your system & perameters. 


Original Gravity: 12.2ºP

Final Gravity: 1.5ºP (ish)

IBU: 23

ABV: 5.7%


330lb Pilsner Malt (79%)

55lb White Wheat Malt (13%)

25lb Flaked/Rolled Oats (6%)

8lb Acid Malt (2%)

or other pH adjustment means to hit 5.2 mash pH


2lb Crystal (5.5%AA) 15 minutes before flameout

3lb Crystal (5.5%AA) at flameout

3lb Citra (12%AA) at flameout


BSI Boulder Blend


Favorite Saison strain, then BSI Boulder Blend after primary


Mash at 150˚F for 60 minutes or until conversion is complete. Boil for 90 minutes. Add hops as specified during boil, as well as whirlfloc & yeast nutrient in final 15 minutes. Cool to 68˚F and pitch Boulder Blend or Saison yeast. Allow fermentation to free rise as high as 80˚F (turn on glycol jacket if it gets higher). Monitor gravity & activity. Once primary is complete, add the Boulder Blend if you havn't, and allow to mature at ambient temperature (65˚F - 75˚F) in fermenter, secondary vessel, or oak for minimum of 2 weeks - i'd suggest 3 or more. Transfer to CO2 purged packaging tank. Make a slurry of .8oz per gallon of sucrose (table sugar) and .8g per gallon of dried champagne yeast then mix/rouse into tank. Package still into bottles, cans, and/or kegs. Allow to naturally carbonate at room temperature for 4-6 weeks.

Additional Options:

Fruit: Add whole or pureed fruit to primary at high kräusen (roughly day 3 or 4)

Dry Hop: Transfer onto muslin sack of 2lb ea Crystal & Citra in CO2 purged packaging tank, allow 5 days before packaging

Sour: Eliminate all hops from recipe, except for 1lb Crystal at flameout