Acid gas and chemical fume control during beer bitterness testing

Home brewers, microbreweries and large-scale production plants often perform quality assurance tests throughout the brewing process to ensure a consistent, exceptional product.

One of the tests in particular determines a beer’s bitterness ratio. Various measurement techniques can be performed to acquire this rating.

The American Society of Brewing Chemists’ (ASBC) Method of Analysis Beer – 23A, is a very common method for performing such test.

The method uses certain chemicals that aid in component separation and extraction.

Chemicals include : 1-Octanol; 2, 2, 4-Trimethylpentane; and 3 N Hydrochloric Acid

Source: WETNEWF.org

According to Method 23A, the steps to determine bitterness ratios are*:

1. Transfer 10 mL of cold carbonated beer to a 50 mL centrifuge tube. Dip the tip of the pipet into octanol and shake off excess.
2. Add 1 mL 3N hydrochloric acid and 20 mL spectrographic grade 2,2,4-Trimethylpentane.
3. Close the centrifuge tube and shake vigorously for 15 minutes.
4. If the phases do not separate, centrifuge the tube until they do.
5. While shaking or centrifuging are underway, prepare an isooctane blank by touching a toothpick or micropipette tip which has been dipped in octanol to the inside of a 1 cm quart curvet. Then pipet in 1-3 mL isooctane, depending on how high you must fill cuvets for accurate reading in your spectrophotometer and cap it.
6. As soon as possible after the completion of shaking or centrifugation, pipet clear isooctane from the centrifuge tube into another 1 cm quartz cuvet and close. The closure prevents evaporation of isooctane, which is beneficial both because the concentration of isohumulone in the cuvet is not increased as octane evaporates, and because the interior of the spectrophotometer is not exposed to hydrocarbon fumes.
7. Set the photometer to 275 nanometers wavelength, zero the instrument with the blank and read the absorption. Multiply the absorption value by 50.

*As adapted by WETNEWF.org

Chemical Fume Exposure

Source: WETNEWF.org

While performing this test, appropriate engineering safety control measures should be used to avoid inhaling gaseous vapor and fume emitted from these chemicals.

The below charts outline the various health and respiratory hazardous as cited in their respective Safety Data Sheets (MSDS).

Engineering Safety Controls

For this type of application, a bench top fume extractor with a 50/50 activated carbon/acid gas blended filter is recommended.

Our Model 200 Winged Sentry has a unique design allowing an adjustable work area through the use of “wing flaps”.

The operator can place these wings in the most effective position for fume capture, or they can be positioned flat against the sides of the unit to conserve space.

In addition, an optional clear lid can be added atop the wings to create even greater fume containment.

A specially-blended 50% activated carbon and 50% acid gas filter works to adsorb chemical and acid gas molecules within the porous structure of the granules so that cleaner air is recirculated back into the work space.

By utilizing the Winged Sentry unit, harmful acid gas molecules generated during the pipetting and transferring of chemicals, and the opening and capping of test tubes, can be captured and filtered before entering the operator’s breathing zone.

Contact Sentry Air

For more information about chemical fume control or to receive a free quote on our fume extraction systems, contact Sentry Air Systems at 800.799.4609, email sales@sentryair.com, visit our website or fill out the feedback form below.