Brewery Labs: Laminar flow hoods aid in aseptic processing of yeast cultures

In an earlier blog post we discussed the use of ductless air cleaners equipped with a specialty-blended carbon filter (50/50 acid gas and activated carbon) for the control of chemical fume during beer bitterness sample testing.

Healthy yeast culture colony on an agar plate. Photo Source:

Healthy yeast culture colony on an agar plate. Photo Source:

While it is important to analyze various quality components of beer in its drinkable state, it is equally if not more important to analyze the quality of each ingredient prior to starting the brewing process.

Every brewer knows that quality beer begins with the meticulous examination and handling of their yeast culture strain.

It is during this early stage where cleanliness and sterility are vital in order to protect the strain from unwanted contaminants that could permeate the beer.

Use airflow to your advantage

In The Brewing Science Institute’s publication entitled Brewers’ Laboratory Handbook: Brewing without the blindfold™, they emphasize the importance of using aseptic techniques when handling and transferring cultures.

The goal of using aseptic techniques is to create a barrier between the contaminants in the environment and the sterile culture cell.

Mold contamination of yeast colony. Photo Source:

Mold contamination of yeast colony. Photo Source:

Many brewers turn to positive pressure enclosures to help create this type of environment. By using positive pressure, airflow is directed away from the specimen rather than towards it in order to reduce the chance of particulate contamination.

A quality positive pressure enclosure (or Laminar Flow Hood), coupled with proper aseptic specimen handling procedures, should result in a yeast culture that is free of unwanted microbes.

What to look for in a laminar flow hood

With so many types of positive pressure systems on the market, it may become overwhelming to select the one most appropriate one for your brewery.

Here are some key features to keep in mind:

  • ISO Rating – The International Organization for Standardization (ISO) has a standard for cleanrooms and associated controlled environments (ISO 14698-1:2003). The standard has strict requirements for classifying clean rooms. Class 1 is considered to be the cleanest environment, while Class 9 and higher have greater allowances for particle count within the hood. Various applications require certain levels of air cleanliness.
  • Filter Media – Not all HEPA filters have the same efficiency rating. It is important to select a HEPA filter that is highly efficient at particles down to 0.3 microns in size. This efficiency may seem stringent since yeast cells range in size from 5-10 microns, but bacteria cells range anywhere from 60 microns down to 0.3 microns.
  • Airflow – When working within an enclosed area such as a laminar flow hood, it is important to consider the amount of airflow the hood produces. Check the CFM (cubic feet per minute) rating on the hood. Too little CFM and you run the risk of ambient air creeping into the hood. Too much CFM may result in turbulence within the hood which may compromise your samples. Look for a hood that offers variable speeds so that you are in control of the airflow level.
  • Size – Most craft and microbreweries use the majority of their space for the actual brewing process, with minimal space remaining for lab equipment. Consider the size, location and installation options of the hood.

Next Step: Talk to Sentry Air

Sentry Air Systems manufactures a range of positive-pressure laminar flow hoods perfect for breweries of any size. Our ISO Class 5 rated, HEPA-filtered enclosures are lightweight, compact, easy to maintain and their plug-and-play operation makes them easy to install.

24-inch wide portable clean room hood (SS-324-PCR)

24-inch wide portable clean room hood (SS-324-PCR)

Our standard widths are 12-, 18-, 24-, 30-, and 40-inches and the hoods come with clear, anti-static vinyl strip curtains across the front opening for greater particle contaminant protection.

A variable speed control knob allows the operator to adjust the airflow, and a fluorescent light at the top of the hood helps illuminate the interior workspace.

The filter chamber houses a HEPA filter with an efficiency of 99.97% down to particles 0.3 microns in size.

The below graphic illustrates the airflow pattern of a Sentry Air laminar flow clean room hood.











On our YouTube channel we posted a video demonstrating our laminar flow hoods during a plant tissue culture application.

If you have any questions about our hoods give us a shout, we’d love to hear from you.

Happy brewing!

Contact Us

For more information on our laminar flow hoods or to receive a free quote, contact Sentry Air at 800.799.4609, email, visit our website or fill out the feedback form below.