Breweries, whether they are large or small, share a common need for quality control (QC) to ensure the consistency and safety of end products. Both subjective and objective QC tests and evaluations can be performed throughout the brewing process.

There are tried and true techniques to measure brew quality and how standard scientific laboratory tests can be used to augment the QC process. Sartorius, a leading international partner in the biopharmaceutical industry, provides the technology, equipment and solutions that can ensure brewing quality at several stages throughout the production process.

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QC in the brewing process

There are numerous subjective definitions and measures for quality in the brewing process, involving taste, smell, appearance and texture. For these purposes, “quality” is defined in terms of maintaining batch-to-batch consistency and safety of the end products. This will guarantee that consumers always get the great-tasting beer that they are accustomed to purchasing.

Throughout the brewing process, there are numerous applications and opportunities to perform QC testing, as outlined in Figure 1.

Figure 1. QC in the brewing process. Source: SartoriusFigure 1. QC in the brewing process. Source: Sartorius

Brewing consists of three major biochemical processes with several steps that include malting, mashing and fermentation.

Malting

During malting, barley grains that are used in the brewing process are germinated and dried under controlled conditions. The quality of the malts can be ensured by maintaining a consistent moisture content, hardness or friability of the grains and consistent color when the malts are steeped in hot water. Furthermore, it is necessary to ensure that the water used throughout the malting process is free of bacteria or yeast strains that could lead to spoilage.

Mashing

The malts are then processed to convert them into mash, and the grain husks are removed to yield a sweet liquid wort. Hops, which are pinecone-like flowers of a female plant in the cannabis family, are added to the wort to counterbalance the sweetness of the barley, adding flavor and aroma and helping preserve the beer. The mixture is boiled, then the malt and hop particles are removed in a whirlpool and allowed to cool. The important QC measurements include the specific gravity of the wort, its acidity (pH) and fermentability.

Fermentation

Yeast, in the form of a slurry, is then added, which converts the wort into beer by producing alcohol and carbon dioxide. The moisture content of the yeast must be controlled prior to fermentation. During fermentation it is necessary to monitor gases such as dissolved oxygen, nitrogen, carbon dioxide and sulfur dioxide; monitor and control microbial and bacteria levels; measure protein, starch and enzyme levels; detect foreign materials and seeds; and evaluate color, clarity and odor. After fermentation, the beer is filtered, pasteurized and then packaged. During these processes, it is necessary to monitor bacteria levels to ensure the safe consumption of the beer.

Sartorius QC tests used in brewing

Sartorius has developed and manufactured several products used in QC for breweries. This equipment is used for spoilage detection, water and quality testing, analytical quality control, moisture analysis, check weighing and air monitoring. Representative products in each of these areas are discussed below.

Spoilage detection

Figure 2. Nutrient pad sets. Source: SartoriusFigure 2. Nutrient pad sets. Source: SartoriusSeveral microorganisms in beverages can cause detrimental changes in aroma, flavor and mouthfeel and ultimately in the overall quality of the product. Sartorius manufactures ready-to-use nutrient pad sets (Figure 2) that are comprised of cellulose pads in sterile packages impregnated with dehydrated media, depending on the intended application. The pads are to be incubated for detecting the specific type and concentration of microorganisms in the beverage that can lead to spoilage.

Water quality

Sartorius manufactures numerous membrane filters, manifolds and pumps to facilitate water testing in order to quickly and efficiently identify potential contaminants in the beverage water. Specific products include the Microsart® e.motion membrane filter and dispenser (Figure 3), the Microsart® manifold and e.jet pump, and the Arium® mini UV water filtration system.

Figure 3. Microsart® e.motion dispenser. Source: SartoriusFigure 3. Microsart® e.motion dispenser. Source: Sartorius

Moisture determination

By controlling the moisture content of raw materials, such as malt, barley and hops, consistency can be maintained while avoiding potential fungal contamination during several stages in the brewing process. Sartorius manufactures moisture analyzers, such as the MA160 and MA37 instruments (Figure 4), which provide automated, fast and accurate results in an easy-to-use and compact form factor.

Figure 4. MA160 and M37 moisture analyzers. Source: SartoriusFigure 4. MA160 and M37 moisture analyzers. Source: Sartorius

Check weighing

Figure 5. Entris® II precision balance. Source: SartoriusFigure 5. Entris® II precision balance. Source: SartoriusSartorius manufactures equipment that enable the precise measurement of contents and ingredients. These products include Entris® II precision balances, which provide effective and reliable weighting results with an easy-to-use interface for error-free operation (Figure 5).

Analytical QC

Analytical tests, such as wet chemistry assays, pH, GC and HPLC can measure several indicators of product quality throughout the brewing process, such as sugar content, nitrogen compounds, salts and minerals, alcohol content, acidity and other chemical compounds. To facilitate these tests, Sartorius provides several tools for sample preparation, such as pipettes, laboratory balances, syringe filters and filter papers.

Air monitoring

Airborne micro-organisms can pose a potential risk of contamination at various stages in the brewing process. Sartorius provides air samplers and ready-to-use gelatin membrane filters that can provide rapid and continuous air monitoring to detect airborne microbes (Figure 6).

Figure 6. MD8 air sampler. Source: SartoriusFigure 6. MD8 air sampler. Source: Sartorius

About Sartorius

Sartorius is a leading international pharmaceutical and laboratory equipment supplier that works with a wide range of customers across several industries. Their focus in the filterable beverage industry includes production and QC testing for beer, wine, spirits, soft drinks and bottled water. Their innovative and intuitive products help increase efficiency and productivity whether in routine or complex lab processes or industry specific workflows. This differentiates Sartorius from other companies, as their solutions allow customers to seamlessly address potential quality problems in the production environment.

More information on how the company supports the beverage industry is available on the Sartorius website.