Four Tips for Maintaining Quality When Contract Brewing

Dana Garves, founder of Oregon BrewLab, explains some of the key tools to ensure impeccable quality standards when working with a contract brewer.


As a contract brewer you face indefinable amounts of scrutiny regarding your brewing craft. Article after article has been written examining all aspects, positive and negative, of contracting brewing. Here The Beer Wench challenges “the negative stigma by explaining the practice and highlighting its positive attributes.” The industry is polarized because nomad brewing can embody either hardcore capitalism or extreme grassroots ideals.

It would seem the industry is split on their views; some believe that a contract brewer is “more likely to spend more time marketing beer than brewing it” yet many uphold Stillwater and Evil Twin in high regard for their craft, uniqueness, or rarity. On one hand, contract breweries have been accused of jumping on the craft bandwagon with little investment, blood, sweat or tears; commonly touted as “in it for the money.” And on the other hand some these brewers are snubbing the very fabric of capitalism by circumventing property purchasing, using vacant brewhouses which would otherwise sit empty, and not playing by the expected rules.

The one thing that remains uncontested in all these articles is that contract brewers face the hardest brewing challenge turned up to 11: Quality. While Quality is a sticky subject for ‘regular’ breweries, it seems to be a bigger issue for contractors. Every single article linked above has to mention that quality is lower or more difficult to achieve for contract brewers. However, quality practices and ideals are concrete and don’t change just because the brewing location has. Below are 4 very detailed steps you can take to ensure a consistent, high quality product regardless where you are brewing.

Record Keeping

Create and print out a brewing and fermenting data sheet for each beer. Record exact values for every brew: water volumes, water pH, hop weight, malt weight, temperatures, etc. Record exact values for each ferment: pitch volume, yeast type and generation, temperature at knockout, temperature at cap, pH every 24 hours, etc. Make these sheets as comprehensive as possible and keep them once they’re filled out. They are your archive. When a batch of beer comes out exactly to your specifications, you have a record of how you did it which can give you insight on how to repeat the same recipe on a different system. In the same vein, you can find the root cause of any problems that arise by identifying any missed target in your record. This is tedious and requires good follow through, but ultimately keeping track will ensure your brews are as close to identical as possible, even if the brewhouses are not.

Purchase portable analysis equipment
No two breweries have the same equipment or instrumentation. Which means in order for your beer metrics to be measured consistently you need to own a few pieces of portable laboratory items. Bring these with you everywhere you brew. You can cut down on error by using the same instrument instead of changing to whatever the current brewhouse has on hand. How the instrument is used, how it’s read, and how you maintenance it will all be under your control and done exactly the same way each time.

First, you need a hydrometer, refractometer, or digital density meter; there’s an option for gravity readings for every budget. I recommend splurging on a high end, more expensive instrument to ensure higher precision.

Second, purchase a hand-held pH meter. pH meters are extremely useful for ensuring ideal mash acidity (5.0-5.5), tracking fermentation progress, and even indicating presence of bacterial infections. If brewing across state lines, do your water research and make sure the pH of the water you are using is adjusted to mimic that of your typical brew. Take pH readings at the same step for each beer at each brewhouse. Track these measurements and changes for enough brews and soon you’ll have expected values every time pH is read.  When a value is outside of the expected range, you can react accordingly to correct the problem indicated.

Conduct Sensory “Panels”

Every brewery should be tasting their beer in a structured method, including contract breweries. Gather your employees before packaging your brew and taste it together, for each beer. Open up the floor for discussion, identifying any off-flavors or highlighting ideal aromas, mouthfeels, or flavors. If you don’t have enough employees, offer these tastings to the employees of the brewhouse. Be open to critics and engage those who have in-depth style knowledge. Take notes. Just like with record keeping, you can look back and see trends between flavor profiles and brewing metrics and fine-tune appropriately. Believe it or not, but sensory doesn’t need to be a long drawn out process to be useful. This is the last defense against shipping a non-ideal brew; at least taste it!

Contract Quality Control

The Alcohol and Tobacco Tax and Trade Bureau (TTB) only require one analysis metric on your labels: Alcohol by Volume. While gravity readings provide a good estimation of alcoholic content, their precision varies from 1-2% despite TTB requirements for an accuracy range of ±0.3%. If the contract brewhouse you’re working from has a way to measure alcohol, I suggest using it for each brew. Otherwise, there are lots of options for contracting your laboratory analysis as well. Search for a local laboratory that is TTB certified. You can find a multitude of tests for very affordable pricing.

These results will be great supplements to the brewing and fermenting records, and sensory notes, providing you with a complete picture of your beer, and the best way to brew it. You’re already facing so many hardships as a contract brewer, let’s take the ‘issue of quality’ out of the equation.

Dana Garves is the founder of Oregon BrewLab, a laboratory facility that provides affordable, fast, and local testing services for the fermentation industry. BrewLab offers precise and accurate alcohol analysis of beer, cider, mead, and kombucha to homebrewers, startups, and established facilities. Dana received her BS in Chemistry at the University of Oregon. She joined the beer industry by building Ninkasi Brewing Company’s laboratory and sensory programs, and later collaborated with the scientists who sent beer yeast into space. She has worked with more than 120 breweries nationwide to maintain and improve their beer quality.

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