Reefer ship (brewery)
The reefer was the classic instrument for trub , oxidation and pitching the wort in the brewery history . In the production of beer specialties such as Kriek , Lambic and Gueuze , it is still essential today.
It is a very flat, open vessel into which the hot wort coming from the brewing pan is transferred ("knocked out"). The hot brew must be cooled down very quickly. First the wort runs through the hop column, in which the hop cones are caught. Then the wort is distributed over the large surface. During a dwell time of 30 to 60 minutes, the hot trub settles , and the flatter the refrigerated ship, the better. The longer the length of stay, the better the cooling and clarifying effect, but also the greater the risk of infection with yeasts or bacteria. Therefore, the reefer ship must always be kept scrupulously clean, unless the infection with selected germs as with the special beers mentioned above is desired.
For today's industrial breweries, however, the risk of infection is too high, so that refrigerated ships are no longer used. However, home and family breweries still have this in operation in some cases, for example with Altbier from the Schumacher and Uerige breweries .
The plate cooler
The plate cooler cools the wort coming from the cooling ship from approx. 80 ° C to the pitch temperature, which is the temperature that allows the yeast to multiply and ferment.
- In the first stage, the wort is cooled to approx. 20 ° C for top-fermented beers.
- In the 2nd stage, the wort is cooled to below 8 ° C for bottom-fermented beers.
When the wort cools down from approx. 60 ° C, the cooling trub flocculates . The amount to be expected is about 0.15 to 0.3 g / l.
So there are three important processes that take place for the wort:
- Separation of the hot or coarse trub
- Formation and removal of the chilled or fine sediment
- Ventilation or oxygenation
and a further concentration of the original wort ( extract content ) through further evaporation.
literature
- Ludwig Narcissus : demolition of the brewery . 4th edition. Ferdinand Enke Verlag, Stuttgart 1980, ISBN 3-527-30860-1 , pp. 189-190 .
Individual evidence
- ↑ Schumacher Brewery : Now it's time to go to the fermentation cellar
- ↑ Uerige : Brewing scheme