Tuesday, September 25, 2007

Kegging My Beer

As this blog unfolds I will get into the details of homebrewing, in hopes that perhaps some newbies will give it a try and that some veterans can share their knowledge. Starting at the back end of the process on this entry, I kegged a batch of beer this weekend, a simple brown ale for a big picnic coming up on October 6. Bridget, as you can see, is fascinated by this process. For the beginners, the large glass container on the left is called a carboy. It is used to ferment the beer in a sealed, microbe-free environment. The one pictured holds 6 1/2 gallons. The typical batch of beer is 5 gallons, so a 6 1/2 gallon keg has plenty of head space above the beer for the foaming that takes place during fermentation.

Please notice the nylon carrying harness. I highly, highly recommend you buy one of these if you use glass carboys. They are cheap (around $12) and I have heard too many horror stories of broken carboys and trips to the emergency room with ghastly cuts. It's not worth it, mates. Get a harness or switch to plastic fermenters.

While Bridget watches in amazement, the beer is being siphoned into a 5 gallon stainless steel keg. I bought a kegging set-up about three years ago and it is fabulous. A five gallon Cornelius keg, commonly used for soft drink dispensers, can hold one whole batch of beer at a time. Just sanitize the keg and your racking cane and tubing, siphon the finished beer into the keg, and hook it to a CO2 tank to carbonate, chill it, and dispense it. No muss, no fuss. But, as with most time savers, it comes at a cost. You'll need a CO2 tank, regulator, keg(s), fittings, tubing, and at least one tap. A kegging setup will set you back about $200-$250. Still, for me it has been a great investment, since I brew at least twice as much with the kegging system as without.
Bottling is the alternative and, for me at least, it's a big hassle. You have to clean the bottles, sanitize the bottles, siphon the beer into a bottling bucket to mix with a bit of priming sugar which will generate the carbonation, fill the bottles, cap them, move them to the cellar, then clean up. With my other responsibilities I find it daunting.

There is one additional time savings with kegs versus bottles that will take a bit of explaining. If you read much literature on homebrewing you will find reference to "secondary fermentation". This means taking the beer out of the first fermentation vessel after fermentation has died down and giving it some aging time in a second fermentation vessel. This aids in the clarity of the beer and the aging gives it time to mellow. Now, as I will explain in a later posting, for lagers this secondary fermentation period is essential. But many homebrewers are finding that for your standard ales it is not. It used to be thought that too much time in the primary fermenter would cause off-flavors. But now homebrewers find that up to four or five weeks in the primary is no problem at all. So I now leave my beer in the primary for three to four weeks, then siphon it straight into the keg, saving the intermediate step of sanitizing a secondary and siphoning into that. I am optimizing my process for speed.

That being said, bottling is a perfectly reasonable option and is much less expensive. More on this in future postings.

THE big thing to remember when you are either bottling or kegging is to keep the oxygen out of the beer! Always remember that before fermentation starts, oxygen is your friend because the yeast need it to be healthy and grow. But after the beer is fermented out, oxygen is your enemy. This was the number one problem I had when I first began homebrewing--when I would rack (siphon) the beer into another fermenter or into bottles I would inadvertently introduce too much air. The beer would taste fine for a few weeks, but then would start to take on some very strong, unpleasant flavors. So now I'm very careful to siphon very gently, always keeping the end of the hose below the liquid line. In fact, when I keg I purge the bottom of the keg with CO2. That way, the beer flows in under a blanket of inert gas and is protected from the oxygen in the air.

After the beer is in the keg (note the empty carboy), I take a hydrometer sample. A hydrometer is a device that lets you measure the amount of dissoved sugar in a solution. This beer had a final gravity of 1.018 (distilled water is 1.00), which means that it will be fairly sweet. This is a little high for what I was shooting for, but should be just fine. I always taste the hydrometer sample, just to get an idea if there's any problem with the beer at this point. This one tasted fine.
Finally, I pressurize the keg a bit and set it in the cellar to age a little more. I have found that it's really not worth getting my nose into a batch of beer until it is at least two months old. Prior to that, it really doesn't taste that great. A little aging, but not too much, generally improves most beers tremendously.


Darwin said...

My brewing buddies and I keep talking about the kegging option. The two big obstacles for us seem like:

a) makes it harder to split a batch (as in, we'd have to buy several kegs + accessories)

b) I'm sure I'd drink much more beer. :-) One bottle and you're done, but experience suggests that if I had it on tap in the house I'd always grab "just half a glass more" and so even more batches would be requred.

On second thought, maybe b) isn't exactly a downside...

Catholic Bibliophagist said...

How appropriate that your daughter is named after St. Briget! She is one of the patron saints of beer.