Open fermentation

Open brewing in brewing is one way of brewing beer . For open fermentation, special bathtubs or tanks for open fermentation are required ^[1] . This method is the most ancient, but still widespread in many European breweries (especially in Germany and Belgium) ^[2] . With open fermentation, unlike fermentation in more modern cylindrical-conical tanks , minimal pressure is exerted on the yeast cells, which positively affects their physiological state. Also, with open fermentation, several more volatile compounds ( esters and higher alcohols) are formed ^[3] , which can positively affect the aroma of beer. The most convenient open tanks or bathtubs are for the production of top-fermented beers, during which the yeast floats to the surface of the beer and can be removed for reuse. With this technology, positive selection of the yeast takes place, and it becomes possible for a long time to maintain them unchanged.

Content

Technology

After cooking, the wort is aerated and pumped into an open fermentation tank, where yeast is also added. For the open fermentation workshop, special demands are made from the point of view of microbiology, since there is a high risk of wort infection with pests of the beer industry (pediococci, lactic acid bacteria , wild yeast) ^[4] . Often, open fermentation tanks do not even have lids. One of the advantages of open fermentation for the brewer is the visibility of the process: after 24 hours after the yeast task, you can usually observe whitening, indicating the beginning of fermentation. After the main fermentation is completed, beer is pumped for fermentation to camp tanks (carbonization occurs in them), or bottled. One of the most famous German breweries combining open fermentation technology and bottling is Schneider Weisse .

It is a common misconception that open fermentation can only be used for top fermented beers. In fact, breweries using this technology produce both top and bottom beer.

The beer styles that are most often produced by open fermentation include, for example, German wheat beer and altbier .

Examples of breweries using technology

Open fermentation technology is used by both industrial and restaurant breweries.

Some of the breweries using open fermentation:

Paulaner
Schneider weisse
Rügener Insel Brauerei Expedition ins Bierreich
Brauerei zum schlüssel

Literature

Kunze V. Technology of malt and beer. - Profession, 2009 .-- 443 p.
Priest F., Campbell I. Microbiology of beer. - Profession, 2005

Links

Notes

↑ Kunze V. Technology of malt and beer. - 9th ed. - St. Petersburg: Profession, 2009 .-- S. 443-464. - 1031 s. - ISBN 978-5-93913-162-9 .
↑ [Library "Milestones" Encyclopedic Dictionary of F.A. Brockhaus and I.A. Efron]. Beer (neopr.) . Beer - “The main fermentation of the wort is done in open vats; after-fermentation in barrels, but first with an open hole. Fermentation tanks are made of wood, cylindrical or oval, with a capacity of 20-35 hectoliters. On the descent of the wort, yeast is set into the fermentation tanks (per 1 gl of wort - 0, 4-0, 6 l). The onset of fermentation is detected after 12-20 hours. the appearance of a thin white foamy tire. After 24 hours, a convex ring of foam forms at the edges of the vat, then the foam begins to take the form of low curls, which lasts 2-3 days. After that, fermentation is still intensified, curls are made higher. Then the curls begin to gradually decrease, then disappear, and a dirty brown coating remains on the surface of the liquid, which has a very bitter taste and consists of proteins, hop resin, yeast cells, etc. In parallel with these external phenomena, the decomposition of sugar occurs, due to which the density of the liquid, determined by a sugar meter, gradually decreases. The main fermentation is considered to have ended if, within a day, the reading of the sugar meter decreases only by 0.05-0.2 °. ”
↑ Kunze V. Technology of malt and beer. - 9th ed. - St. Petersburg: Profession, 2009 .-- S. 811-823. - 1031 s. - ISBN 978-5-93913-162-9 .
↑ Priest F., Campbell I. Microbiology of beer / Meledina T.V. - 3rd ed. - St. Petersburg: Profession, 2005 .-- 368 p. - ISBN 5-93913-087-9 .

[1] Kunze V. Technology of malt and beer. - 9th ed. - St. Petersburg: Profession, 2009 .-- S. 443-464. - 1031 s. - ISBN 978-5-93913-162-9 .

[2] [Library "Milestones" Encyclopedic Dictionary of F.A. Brockhaus and I.A. Efron]. Beer (neopr.) . Beer - “The main fermentation of the wort is done in open vats; after-fermentation in barrels, but first with an open hole. Fermentation tanks are made of wood, cylindrical or oval, with a capacity of 20-35 hectoliters. On the descent of the wort, yeast is set into the fermentation tanks (per 1 gl of wort - 0, 4-0, 6 l). The onset of fermentation is detected after 12-20 hours. the appearance of a thin white foamy tire. After 24 hours, a convex ring of foam forms at the edges of the vat, then the foam begins to take the form of low curls, which lasts 2-3 days. After that, fermentation is still intensified, curls are made higher. Then the curls begin to gradually decrease, then disappear, and a dirty brown coating remains on the surface of the liquid, which has a very bitter taste and consists of proteins, hop resin, yeast cells, etc. In parallel with these external phenomena, the decomposition of sugar occurs, due to which the density of the liquid, determined by a sugar meter, gradually decreases. The main fermentation is considered to have ended if, within a day, the reading of the sugar meter decreases only by 0.05-0.2 °. ”

[3] Kunze V. Technology of malt and beer. - 9th ed. - St. Petersburg: Profession, 2009 .-- S. 811-823. - 1031 s. - ISBN 978-5-93913-162-9 .

[4] Priest F., Campbell I. Microbiology of beer / Meledina T.V. - 3rd ed. - St. Petersburg: Profession, 2005 .-- 368 p. - ISBN 5-93913-087-9 .