Quantcast
Namespaces
Variants
Actions
Personal tools

Primary Fermentation

(Difference between revisions)
Jump to: navigation, search
m
(The Fermentation Environment)
Line 9: Line 9:
 
[[Image:Carboy_fermenting_cup_airlock.jpg|thumb|130px|A Carboy fermenting beer with a Three Piece Airlock on top.]]
 
[[Image:Carboy_fermenting_cup_airlock.jpg|thumb|130px|A Carboy fermenting beer with a Three Piece Airlock on top.]]
 
{{sectionStub}}
 
{{sectionStub}}
Once the wort is aerated and the yeast has been added (pitched), the yeast should begin to reproduce, and eventually ferment the beer. Signs of fermentation include bubbles (burps) in the airlock, and a layer of foam (called "Kraeusen") on top of the beer. The amount of time between pitching the yeast and the first signs of fermentation is referred to as "lag time". The goal of the attentive brewer is to keep the lag time within a reasonable limit. A short lag time (< 8 hours for ales, < 16 hours for lagers) is generally desirable and a very long lag time (> 24 hrs) increases the chance for infection. As such, utilizing the yeast starter and aeration methods described above, as well as keeping the fermentation temperatures within the accepted range, can help to reduce lag time. While most ale fermentations should be mostly complete within 10 days (this can be seen by reduced or stopped airlock activity, and the krausen sinking to the bottom of the fermenter), some may take longer, and lagers may take 3 weeks or more to finish. On the other hand, depending on the health of the fermentation and other variables, some fermentations may be vigorous enough to finish in 2 or 3 days. As a general rule, lagers ferment at colder temperatures than ales. These ranges vary from yeast to yeast, but generally speaking, the standard ranges are as follows:
+
Once the wort is aerated and the yeast has been added [[Pitching the Yeast|pitched]], the [[yeast]] should begin to reproduce, and eventually [[ferment]] the beer converting the fermentable sugars into alcohol and CO2.  
  
*Ale Fermentation Temperature Ranges: 60*F - 70*F (15*C - 20*C)
+
 
*Lager Fermentation Temperature Ranges: 46 *F - 58 *F (8*C - 14*C)
+
Signs of fermentation include bubbles (burps) in the airlock and a layer of foam called [[Kraeusen]] on top of the beer. The amount of time between pitching the yeast and the first signs of fermentation is referred to as "lag time". The goal of the attentive brewer is to keep the lag time within a reasonable limit. Lag times typically vary from as short as a few hours to as long as 48 hours. Using a yeast [[starter]] and [[aeration]] methods, as well as keeping the fermentation temperatures within the accepted range, can help to reduce lag time.
 +
 
 +
 
 +
Most ale fermentations should be mostly complete within 10 days although fermentation times can vary anywhere from 4 days to 3 weeks.  Lagers may take longer to finish fermenting, typically 2 to 3 weeks, and require at least a month of [[lagering]].
 +
 
 +
 
 +
A critical component to the fermentation environment is the temperature of the [[wort]] at [[Pitching the Yeast|pitching]] and during fermentation.
 +
 
 +
 
 +
===Fermentation Temperature===
 +
 
 +
The appropriate fermentation temperature varies from one [[yeast]] strain to the next.  In general, ales ferment anywhere between 60 and 70 degrees F while lagers ferment between 50 and 60 degrees F.  Fermenting at too low a temperature can result in a slow or "stuck" fermentation in which the [[yeast]] become dormant before all the sugars have been converted.  Fermenting at too high a temperature can lead to [[off-flavors]] due to the production of [[esthers]].  There are different steps brewers can take to control the temperature throughout the fermentation process.
  
 
==Choosing the Right Fermentation Vessel==
 
==Choosing the Right Fermentation Vessel==

Revision as of 13:07, 29 September 2007

The Beer Brewing Process
1. Preparing the Ingredients
2. Cleaning and Sanitation
3. Making the Wort
4. Boiling the Wort
5. Cooling, Racking, and Aerating
6. Pitching the Yeast
7. Primary Fermentation
8. Conditioning the Beer
9. Packaging and Carbonation
10. Dispensing and Serving

Primary fermentation is when the wort finally becomes beer through the conversion of sugars into alcohol and carbon dioxide. This conversion is done by the yeast which "eat" the sugars; you just need to provide the right conditions for the yeast to do its job.


Contents

The Fermentation Environment

A Carboy fermenting beer with a Three Piece Airlock on top.

This section is a stub.
Help make this wiki better and contribute some content.

Once the wort is aerated and the yeast has been added pitched, the yeast should begin to reproduce, and eventually ferment the beer converting the fermentable sugars into alcohol and CO2.


Signs of fermentation include bubbles (burps) in the airlock and a layer of foam called Kraeusen on top of the beer. The amount of time between pitching the yeast and the first signs of fermentation is referred to as "lag time". The goal of the attentive brewer is to keep the lag time within a reasonable limit. Lag times typically vary from as short as a few hours to as long as 48 hours. Using a yeast starter and aeration methods, as well as keeping the fermentation temperatures within the accepted range, can help to reduce lag time.


Most ale fermentations should be mostly complete within 10 days although fermentation times can vary anywhere from 4 days to 3 weeks. Lagers may take longer to finish fermenting, typically 2 to 3 weeks, and require at least a month of lagering.


A critical component to the fermentation environment is the temperature of the wort at pitching and during fermentation.


Fermentation Temperature

The appropriate fermentation temperature varies from one yeast strain to the next. In general, ales ferment anywhere between 60 and 70 degrees F while lagers ferment between 50 and 60 degrees F. Fermenting at too low a temperature can result in a slow or "stuck" fermentation in which the yeast become dormant before all the sugars have been converted. Fermenting at too high a temperature can lead to off-flavors due to the production of esthers. There are different steps brewers can take to control the temperature throughout the fermentation process.

Choosing the Right Fermentation Vessel

This section is a stub.
Help make this wiki better and contribute some content.

Airlocks and Blow-Offs

This section is a stub.
Help make this wiki better and contribute some content.

Advanced Fermentation Temperature Control

This section is a stub.
Help make this wiki better and contribute some content.

When is Primary Fermentation Complete?

This section is a stub.
Help make this wiki better and contribute some content.

What do I do next?

Once primary fermentation is complete, you may want to take extra measures by way of Conditioning the Beer, such as a secondary fermentation or lagering. Or, beginning brewers can skip straight to the final step in the beer brewing process: Packaging and Carbonation.