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FERMENTATION
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| The fermentation plays an essential
roll in the quality of the beer, in individual thanks to secondary
products like the superior alcohol and esters; it is also the stage
of the manufacture most difficult to control. The leavening that is reused
from a fermentation to another one does not have a stable metabolism; it degenerates. This degradation does not have to an infection by
presence of other microorganisms, nor habitually either due to a mutation;
due to progressive modifications of the cellular membrane and the
enzymatic activity of the leavening.
The fermentations are modifications of the cellular metabolism, that is to say, the set of biochemical and physical modifications. This metabolism includes/understands the catabolism and anabolism. |
A complex liquid has been prepared and
it has been purified carefully until the moment for adding the brewing
leavening to produce his fermentation. At the end of this when you sweeten
them they have been transformed until alcohol and carbon dioxide gas will
have the beer. After the fermentation the beer is separated of the
leavening, which can be used to ferment but must, later. The beer leaves a
certain time in rest during which certain qualities pay attention and it
is clarify naturally; later it is leaked.
The main product obtained during the fermentation is the etílico alcohol but it knows two types fermentations in brewery the fermentation of surface and the fermentation of bottom |
| Fermentation of surface. - Leavening is used that goes to the surface of the liquid after filtering the fermentation. Of this system beers take control Ale type, Porter, Lambic. | Fermentation of bottom. - A type of leavening is used that settles to the bottom of the bathtub after to have carried out the fermentation of must with her make beers Lager type. In the national breweries east type of fermentation is used. |
| Description of the process | |
| It is added to cold must,
leavening in a calculated amount, so that it is in the must of 8 to 10
million cells by cc. For the concentrated must fermentation, a million
cells by cc by each degree are used plate of must. The amount of leavening
previously determined is diluted in must and soon it is injected to the
line of cold must during the cooling. The total amount of leavening that
is injected calculates having the account the volume of must that goes to
contain the bathtub of fermentation.
The initial temperature of fermentation can vary between 6 to 10 ºC. Once the fermentation begins are appraised like well-known changes, the reduction of the extract, the carbon dioxide gas production and the heat loosening; during the fermentation the temperature with atemperadores is controlled the reduction of the density regulating (coils or jackets), around which cold water circulates or gets sick of too much salt or water glicolada to temperatures that oscillate between 1 to 2ºC for the case of the water and -5 to -10ºC. for the case of the brine or the glicolada water. In order to collect the carbon dioxide gas that is come off the fermentation, commonly the tank is connected by the superior part with two pipes; one that goes outdoors and the other than goes to the plant of carbon dioxide gas purification. In the carbon dioxide gas plant, this one is purified and liquefied with the purpose of injecting it to the beer later. When it is reached the extract limit that is to where it is going away to let to him ferment opens the cold to be able to cool the beer and so that the leavening is fed. One is able to cool the beer until 5ºC. and it is suspended sent of carbon dioxide gas to the plant, soon the beer to the maturation tanks is pumped and the leavening recovers. To the amount of leavening obtained in each fermentation leavening harvest is denominated to him, the normal thing is to obtain 4 times the amount of added leavening. |
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