Brewing Up - Industry Focus
How is pure water, malted barley, hops and yeast transformed into beer?
- In the brew house, different types of malt are crushed together to break up grain kernels to extract fermentable sugars and produce a milled product called grist.
- The grist is transferred to a mash tun where it is mixed with heated water in a process called mash conversion, using natural enzymes in the malt to break the malt’s starch down into sugars.
- The mash is then pumped into the launter tun where a sweet liquid known as wort is separated from the grain husks.
- The wort is collected in a vessel called a kettle that is brought to a controlled boil when hops are added.
- After boiling, the wort is transferred to a whirlpool for separation; malt and hop particles are removed to leave a liquid.
- The liquid goes into a vessel and yeast is added whilst filling.
- The yeast converts the wort into beer by producing alcohol, flavors and carbon dioxide, which is used later in the process.
- After fermentation the ‘green’ beer needs to mature to develop flavors and a smooth finish.
- When reaching its full potential the beer is filtered, carbonated and transferred to a bright beer tank in which it is cellared for three to four weeks. When completed the beer is ready to be bottled, canned or kegged.
One option to achieve this is to produce seals in a perfluoroelastomer (FFKM), such as Trelleborg’s Isolast®. A terpolymer of monomers in which all hydrogen atoms are replaced by fluorine; the lack of hydrogen in the molecular chain increases the material’s chemical resistance. The cross-linked molecular chains combine the elasticity and sealing power of an elastomer with the chemical resistance and thermal stability of polytetrafluoroethylene (PTFE).
The universal compatibility of FFKM is also important due to the trend for shorter runs in breweries. Craft beers and mixed beer beverages tend to be manufactured in smaller quantities and because one and the same bottling plant fills different kinds of beer and mixed beer drinks, there is a need for more flexibility in processing systems. Seals therefore need to be resistant to different beer and mixed beer ingredients, whatever they may be.
In addition, there is a need with each beverage production run change, the system will be subjected to harsh Cleaning In Place (CIP) and Sterilization In Place (SIP) regimes. Ever more frequent cleaning can quickly destroy standard seals, so in some cases the only way to ensure the expected seal life and minimize system downtime, is by using FFKM. Effective and long-lasting chemical resistance is also vital in the elimination of flavor or aroma carry over from one drink to another.