I must confess to sometimes just going down into the cellar and stare at the magical dance being performed inside the carboys during the peak of primary fermentation. The sugars and yeasts seem to dance around the fermenter in synchronized motion or just explode like fireworks.
Today is a cloudy, cold, wet, New England day (sounds very British like) so I went down to the cellar to check on the progress of my brews and found myself again just staring at the fermenters. So I went upstairs, got my Flip Camcorder (love these things, so easy to use and a snap to publish, all the software is actually on the camera) and recorded some snippets. Enjoy -
Here is a poem about ale I have kept with me through the years, the 3rd verse seemed apt right now. Its by W. H. Davies, a Welsh poet who lived in the late 1800′s through the outbreak of the 2nd World War in 1940. More here.
Aleby William Henry Davies
Now do I hear thee weep and groan,
Who hath a comrade sunk at sea?
Then quaff thee of my good old ale,
And it will raise him up for the
Thoul’t think as little of him then
As when he moved with living men.
If thou hast hopes to move the world,
And every effort it doth fail,
Then to thy side call Jack and Jim,
And bid them drink with thee good ale;
So may the world, that would not hear,
Perish in hell with all your care.
One quart of good ale, and I
Feel then what life immortal is:
The brain is empty of all thought,
The heart is brimming o’er with bliss;
Time’s first child, Life, doth live; but Death,
The second, hath not yet his breath.
Give me a quart of good old ale,
Am I a homeless man on earth?
Nay, I want not your roof and quilt,
I’ll lie warm at the moon’s cold hearth;
No grumbling ghost to grudge my bed,
His grave, ha! ha! holds up my head.
Been taking some pictures during the fermentation process of the Best Bitter we used as the example in the Brewing Day post. I have taken a picture for each day of the primary fermentation stage, typically a 7 day process.
For most homebrewers fermentation is typically done in 2 stages though it can be done in a single stage or more than 3, depending on the recipe.
1) Primary fermentation is the process by which wort finally becomes ale through the conversion of sugars into alcohol and CO2. This conversion is done by the yeast eating the sugars when given the right temperature conditions, dictated by the strain of yeast we use. Stopped fermentation’s tend to occur if fermentation temperatures are too high or too low.
An airlock is used to ensure the CO2 escapes and no microbes get into the wort. If the fermentation becomes a little too active the foam can run out of space and blow out the top of the airlock (yuck its messy, see image below and here). If this circumstance arises the use of a blow-off tube is recommended, preferably before the airlock overflows with foam and crud (the proper term is Krausen). A blow-off tube is typically a hose attached in place of the air lock with the other end of the hose is submerged into a bucket of water or sanitizer. The CO2 continues out of the hose into the bucket along with any of the krausen.
So when is the primary fermentation complete? In my experience it should be left in the primary fermenter for at least 7 days, even if fermentation appears to be complete. The only way to determine whether a fermentation has finished is by taking a gravity reading on consecutive days. If this reading stays constant, fermentation is complete. You can try to guess by seeing if the bubbles have stopped or the krausen has subsided but these methods are inaccurate and can be misleading. If you think your fermentation is done, use your hydrometer to make sure. You will need special equipment, such as a “Beer Thief” to safely extract a sample from the carboy.
2) Secondary fermentation is really a misnomer as no actual fermentation occurs during this phase. It is best described as the “Conditioning and Clearing” phase. For the complete beginner this phase can be skipped and the ale can move on to priming and bottling (upcoming post). If the ale is to be kegged then this secondary phase is essential to avoid clogged lines. Secondary fermentation is simply the transferring or “racking” of the ale into a second, clean, carboy complete with airlock and then stored in a cool room away from sunlight.
The primary purpose of the conditioning phase is to clear and bulk age the ale before it is placed in bottles or kegs. During this phase yeast and solids remaining from the primary fermentation settle out and the ales flavours begin to mellow and meld together. In my experience hoppy, bitter beers tend to be a little too bitter if not left to condition for a while. Flavours also take longer to develop in higher alcohol ales. Over time the more delicate flavours of the specialty grains will come through and its well worth the extra wait. (Remember patience is one of my 3 golden rules)
Duration of the secondary phase varies by recipe. Some recipes call for an aging to be done at lower temperatures, called “Cold Conditioning”. This process is typical for beers aged over long periods, especially beers with higher alcohol content. Most basic recipes though call for an additional 7 days in the same conditions as the primary fermentation phase. It is also typical during this phase to add additional flavours and adjuncts such as spices, fruit extracts and oak chips as well as the process called dry-hopping.
Dry-hopping has become very popular in American Ales, specifically the American IPA. As much of the aroma qualities of the hops are either boiled off during the brew or lost in the primary fermenter it has become popular to add a slug of hops into the secondary. This process captures the aroma of the hop without imparting any of the bitterness. Some professional brewers have taken this art to the extreme, creating equipment for straining an ale through hops prior to serving (here). Simply add the prescribed amount of hops to the secondary, secure airlock, and leave in cool place.
Some brews require an additional conditioning phase but this is rare. The 90 min IPA I brew is a 3 stage process with the 3rd phase used as a long cold conditioning process. The beer is racked a 3rd time to remove the ale from the hops used for dry-hopping in the second stage and off the yeast and proteins that settled.
With the end of secondary fermentation we are now 1/2 way through the brewing process for most typical ales. In our next “Getting Started” post we will focus on priming and bottling before getting down to my favorite section of all, the drinking.