barleyWith Oktoberfest coming up soon, people around the world will be enjoying pints of cold, crisp beer. Have you ever wondered what’s behind that hoppy taste?

Brewing beer requires good quality raw ingredients. One of the primary grains used in the malting and brewing process is barley. In choosing the strain of barley, the producer is ultimately selecting the taste and body of the finished product.

Five substances should be considered during malting and brewing:

  • Cell wall polysaccharides
  • Starch
  • Protein
  • Lipids
  • Polyphenols

Cell wall polysaccharides, especially beta-glucan (β-glucan), restrict the amount of extract during malting. Undegraded, they also increase viscosity and decelerate filtration, falling out of solution as hazes and precipitates. Molecules of β-glucan are long and have very high molecular weights (high MW). With their cross-linking capability, this means they are very viscous and prone to unravel when beer containing β-glucan is centrifuged. The amount of β-glucan in barley (link to IBD Learning article) is dependent upon the genetic type used and its growing environment. Using photometric analysis (link to product page), the β-glucan content of barley can be determined.

 

Measuring High MW β-Glucans

Measuring β-glucan has challenged many analysis techniques, since pH and temperature can interfere with results. A rapid two reagent method for analyzing β-glucans from wort and beer samples was developed for use with a multipurpose discrete analyzer (link to product page). With this method, β-glucan forms a complex with reagent R2 that is proportional to the concentration of High MW β-glucan in the sample. The reaction is then measured photometrically. Results were similar when compared to the traditional Calcofluor method using flow injection analysis (FIA). In addition to measuring β-glucan, the analyzer can simultaneously measure the following parameters: color, sulfur dioxide (SO2), pH, and free amino nitrogen (FAN) from the same sample. Measurements are in compliance with standards set by the European Brewery Commission (EBC) and the Analytical Society of Brewing Chemists (ASBC).

 

Quality and Consistency with a Brewery Supplier

Murphy and Son Limited (link to case study), located in Nottingham, UK, was established in 1887 as a supplier of brewing components. Although beer consumption in pubs has dropped a little, demand for a higher quality bottled product for consumption at home has increased. About three years ago, the company decided to automate the testing procedures in their laboratory. It would consume an entire day to complete seven tests on eight samples in the past. Now, in one hour 50 tests are finished that include measures for calcium, magnesium, chloride, sulfate, nitrate, alkalinity, pH, malic acid, acetic acid, bitterness, color, SO2, and FAN. An average of 25 samples is tested per day throughout the production process. Water, cider, and juice concentrates are also tested, allowing the microbreweries to maintain efficiency while creating a high-quality end product.

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At Radeberger (link to case study) in Frankfurt, Germany, in-process and production samples are tested for bitterness, FAN, SO2, β-glucan, and color. Using a continuous flow analyzer (CFA), it used to take half a day with a dedicated technician to run the required tests. Now the tests for their average of 30 samples per day are complete in one hour. In addition, less sample volume and reagents are required.

 

Additional Resources:

 

Visit our online Food Community pages, a resource dedicated to our Food and Beverage customers and featuring the latest on-demand webinars, videos, application notes, and much more.

 

Are you measuring β-glucan in your malt and beer samples, and is automated photometric determination of interest to your laboratory? If so, we would like to hear about your experiences.