Wednesday, April 27, 2011

Force Carbonation

When you first start kegging your beer the one thing you need to decide is what method you are going to use to force carbonate your beer. Below I have set out the steps for force carbonating your beer using two different techniques. The first few steps are the same regardless of the method you are going to follow, then the techniques diverge, I will lay out the steps to follow for each technique and then I will give the reasons I follow one of the techniques.

My set up, a 6kg Co2 tank sits outside
the fridge and a gas line is fitted through
a hole drilled in the kegerator door.
Step 1 - Transfer your beer to the keg, connect the Co2, turn on,  and purge the keg with a few lifts of the pressure release valve. Doing this will help seal the lid properly and also expel any oxygen present in the deadspace at the top of your keg.
Step 2 - Turn off the gas and let your keg refrigerate for 24-48 hours. This will allow the temperature of the beer to drop which will result in easier absorption of the Co2 once you start to force carbonate.

Method 1: Rock and Roll
Step 3 - Turn the gas on and raise to a PSI of about 45, you will now hear the Co2 entering the keg, now gently place the keg across your knee making sure the 'gas in' post is at the top of the keg*. Now gently rock the keg back and forth across your knee for about one minute. As you do this you will hear the Co2 entering the keg constantly. It is now being absorbed into the liquid and the tank is refilling the dead space with more Co2.
Step 4 - After a minute turn off the gas at the regulator and continue to rock the keg back and forth. The gauge on your regulator should now start to drop. You are looking for it to stop at between 20-23 PSI, if it falls below this it is under gassed and you may need to repeat steps 3 and 4. If it finishes above this the beer may be over gassed and so you will need to vent the excess gas.
Step 5 - Leave the keg to sit for one hour and then turn the gas back on to 15 PSI. Your beer should now be carbonated to the right level.

*this is done to try and alleviate the risk of liquid entering the gas line, if liquid gets sucked up the gas line to your regulator it will ruin it.

Method 2: Set and Leave
Step 3 - Turn the regulator to the desired PSI based on the table below. In order to determine the liquid temperature of your beer, place a spirit thermometer in a glass of water in your kegerator while the beer is left to cool for 24-48 hours, this should give you an accurate enough reading for the liquid temperature inside your kegerator.

Temp 9 10 11 12 13 14 15 16 17
7 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8
8 1.9 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7
9 1.85 1.9 2 2.1 2.2 2.3 2.4 2.5 2.6
10 1.8 1.8 1.9 2 2.1 2.2 2.3 2.4 2.5

Temperature is listed down the left hand side and PSI across the top, so for example if the liquid temperature is 8c and you are looking for a carbonation level of 2.1**, then you need to set your regulator to 11.

Step 4 - Be patient, following this method your beer should be carbonated to the desired level in 4 days, however if you can leave it for a week then all the better.

** The level of carbonation you aim for really depends on the style of beer you are brewing and also your personal preferences, here is a rough guide of what you should be aiming for with the most typical styles:

My current APA carbonating
at a PSI of 10.
British Style Ales: 1.5 - 2
Stouts/Porters: 1.7-2.3
American Ales/Lagers: 2.2 - 2.7
German Wheat Beers: 3.3 - 4.5

My Technique
Personally I use the set and leave method. I find this to be very consistent, and extremely straight forward. You determine the PSI based on the table above, set your regulator and then leave it alone. Moreover when you come to serving your beer you can leave the regulator as is and leave your gas turned on all the time (although do make sure you have no leaks). Due to the fact that equilibrium will have been achieved between the keg and Co2 tank the only gas that will be used is as you dispense the beer and so it is an easy, no hassle way of carbonating and dispensing your beer.

Wednesday, April 20, 2011

Metalman Pale Ale

I posted a few months ago with regard to the imminent launch of Metalman Brewing's first beer, a pale ale. I know the co-founders through Beoir and so I was really excited to sample their first professional brew (although I had tasted a number of their pilot home brew batches). Through one thing and another I never made it to their launch night and so it was only last Saturday in L Mulligan Grocers in Dublin that I got the opportunity to try Metalman Pale Ale for the first time.

I have to say that I really enjoyed this beer. It is great to see an Irish brewery brewing American style beers and doing it so well. Metalman Pale Ale has lovely citrus and floral notes in the aroma, this is followed by a nice body and finishes with a nice stiff level of bitterness. It is very refreshing and I can see it making a great summer session beer.

The great news is that Metalman are set to launch their second beer this weekend, a seasonal special, Windjammer. I have not tried this beer yet and so i'll give you the description from Metalman themselves:

American style amber, but hopped exclusively with New Zealand hops. An antipodean extravaganza, with Southern Cross and Pacifica for bittering and flavouring, with Nelson Sauvin included in the late additions. 

Sounds great and I have been told that Windjammer should be available in the Bull & Castle in Dublin from next week.

I have to say I really like the direction that Metalman is taking, I think they have hit the mark in relation to their branding and their product range to date and hopefully in the not too distant future we may see Metalman bottling some of their range. You can find out where you can try Metalman beers through the 'Find a Stockist' section of their website.

Monday, April 11, 2011

To Dry Hop or Not

Dry hopping in brewing is the technique of introducing hops to the beer later in the process than is usual. Typically hops are introduced to the beer during the boil, during the boil early hops impart bitterness, those added in the middle to late boil impart flavour and hops added late or at flame-out impart aroma. The aroma and flavour of hops can be quite delicate and dry hopping is used to boost the hop flavour and aroma of a beer. Typically dry hopping can occur in two ways. The most usual way is to dry hop the beer in secondary after the vigorous primary fermentation has completed, the second way is to dry hop beer while it is in its serving keg. The latter is something that I have done with some success in the past by adding a bag of hops to a keg and leaving the hops in the keg during dispensing.

With my latest beer I wanted to do a comparison between a beer that was dry hopped and one that was not. So yesterday I bottled eight beers from my Lady Liberty Pale Ale (straight from Primary) and then transferred the remaining 19 litres to a carboy and dry hopped this with 25g of cascade hops. The carboy will be left for a week before being transferred to a keg and carbonated. I then should be able to do a taste test between the bottled beer and the dry hopped keg beer.

I will report back with my findings in 2-3 weeks.