- The taste and quality of beer greatly depend on the quality of the water used to brew it. pH and conductivity measurements determine its quality.
- Globalization is putting massive competitive pressure on breweries. Maintaining high beer quality is key to remaining successful in the market.
- Using process analytics guarantees beer quality and optimizes process management at the same time.
Not just a matter of taste: pH, conductivity and oxygen measurement in brewery processes
The brewing water’s pH value and salt content are major determinants of the taste and quality of beer. This is why depending on the substances it contains, raw or potable water must be subjected to various types of treatment ranging from reverse osmosis and chemical treatment to filtration. SE 558 pH sensors or SE 605 Memosens conductivity sensors are used to monitor the brewing water alkalinity and salt content required for each specific style of beer.
Mashing process: highly pH dependent starch-sugar conversion
In subsequent processes, pH measurement also plays a major role. After the brewing water is mixed with milled malt in the mash tun, enzymes convert the starch it contains into maltose. This highly pH-dependent process takes place in the 5.4 to 5.6 pH range. In the next step, wort boiling, hops are added to control the future beer’s taste and shelf life, its specific gravity is set and the pH value lowered. Because the SE 555 pH sensor can be sterilized with superheated steam and is biocompatible, it is ideal for monitoring these processes.
Oxygen measurement – essential for reliable process management
Afterward, the trub – hops debris and precipitated protein – is separated in a whirlpool and metered yeast and oxygen are added to the wort in order to trigger the fermentation process. Rigorous rules apply for the yeast. To ensure optimal quality, the pH value and dissolved oxygen content are monitored during yeast breeding. Since the dissolved oxygen content determines yeast vitality during fermentation and taste development as well, oxygen measurement is essential for reliable process management. At this point, the SE 706 oxygen sensor in the hygienic stainless steel variant guarantees reliable inline measurement.
Next, the wort turns into green beer in storage tanks. At this stage, low oxygen content retains the beer’s taste. And continuous oxygen measurement also allows leaks in the storage tanks to be detected in time. Before it is bottled, beer is filtered and stored in pressurized tanks. To safeguard taste and prevent oxidation, maximum limit values for the concentration of oxygen must be complied with. Some large breweries also set the precise alcohol content of the beer by diluting it with degassed water. The degassing process is monitored by measuring the dissolved oxygen. The same applies to bottling, in which the oxygen concentration must remain below 25 ppb to maintain shelf life and taste.
CIP: Dosing rinse media with inductive conductivity measurement
In order to comply with the rigorous hygiene rules for food production, the systems involved in brewing beer must be cleaned by alternately flushing with a sodium hydroxide solution and acid (often nitric acid) at temperatures of around 65 °C (CIP process). The concentration of the CIP media (intrusion) is controlled based on inductive conductivity measurement with a SE 680 sensor. During the final rinse of the cleaned process lines, the complete removal of all rinse media is verified using the SE 605 H conductivity sensor.
Brewery wastewater treatment
Last but not least, Memosens technology is also applied in the treatment of brewery wastewater, which requires sensors such as the SE 554 pH sensor, the highly chemical resistant SE 655 for measuring inductive conductivity in heavily polluted media and the long-term stable SE 715 oxygen sensor. Since brewery wastewater treatment assumes an unusually high load of debris, automated cleaning systems at the measuring points involved are recommended.
Return on Investment
- In the moist environments of breweries and for system cleaning, the contactless inductive Memosens plug & play system guarantees unrivaled measurement reliability and quality.
- Reliably accurate measurements are essential for high product quality and safeguard the brand’s key properties from the consumer’s point of view.
- Reduced costs thanks to longer sensor service life: Memosens detects the number of CIP/SIP cycles and suggests maintenance intervals to extend sensor service life.