Month: May 2009

An important characteristic in beers is the ability of the beer to retain a nice foamy headfor a long period of time. Commercial brewers go to great lengths to improve head retention by a variety of additives. However homebrewers also have access to quite a few ingredients and additives that can help your foam last until the last drop. Note that enhancing head retention is closely related to enhance the body of the beer.

Foam is the result of CO2 bubbles rising through the beer. These bubbles attach themselves to substances in the beer and form a skin around the bubble. Obviously the more CO2, the more bubbles, but the goal of the brewer is not bubbles but stability of the head. As foam collapeses, evaporating bubbles tend to solidify the beer near the surface, allowing more beer to be poured with less foaming after about a few minutes have passed. Head stability depends on the presence of substances with low surface tension in the beer which can form stable elastic bubbles. The two primary contributors to head retention are certain high molecular weight proteins and isohumulones (alpha acids from hops). Therefore beers with more proteins that are highly hopped will have a higher head retention.

Methods for Improving Head Retention

We will explore the following possibilities:

The simplest way to describe the bittering potential of a given hop sample is to use Alpha Acid Units (AAU) or Homebrew Bittering Units (HBU) (they’re the same). For the sake of discussion we will use the term AAU, which is calculated as follows:

AAU = AA * W

where:

* AA = alpha acid % provided with the hops
* W = weight of the hops in ounces

AAU’s are literally hundredths of an ounce, so the units would be ounces. This is a bit awkward, and they are usually discussed as if they are “unit-less”. It is generally assumed that, when using AAU or HBU, the batch size is the standard homebrewing unit of 5 gallons. If a beer is said to have 10 AAU’s of bitterness in it, and it is a 5 gallon batch, there would probably be no confusion. On the other hand, if it is a 10 gallon batch, there is actually half the AAU’s per gallon when compared to the 5 gallon batch and the beer would be quite different. Another drawback to using AAU’s is that they don’t consider the utilization obtained from long, intermediate, or short boil times. Fudge factors are sometimes added but at best they offer a rough approximation.

Beer, it’s the best damn drink in the world.
Jack Nicholson

Beer is living proof that God loves us and wants us to be happy.
Benjamin Franklin

Beer. Now there’s a temporary solution.
Dan Castellaneta

He was a wise man who invented beer.
Plato

I look like the kind of guy who has a bottle of beer in my hand.
Charles Bronson

Milk is for babies. When you grow up you have to drink beer.
Arnold Schwarzenegger

Rugby is great. The players don’t wear helmets or padding; they just beat the living daylights out of each other and then go for a beer. I love that.
Joe Theismann

There is no such thing as a bad beer. It’s that some taste better than others.
Billy Carter

From: Janis Gross [mailto:janis@brewersassociation.org] Sent: Wednesday, May 13, 2009 12:46 PM Subject: NHC Information   Hi everyone, Congratulations to all of the First Round winners of the AHA National Homebrew Competition (NHC) this year!   I know all of you are anxiously awaiting the information you’ll need to send your entries to the Final Round of the competition. Most of this information can be found in the National Homebrew Competition Rules & Regulations document, but I’ll highlight it here as well.   If your entry placed 1st, 2nd, or 3rd, of if you have received an Administrative Advance from me, then I will send you the information on where to send the Final Round bottles.  This mailing will most likely start next week and take all week to complete.   + You need to send 3 bottles for the Final Round.  If you only have 1 or 2 bottles, then send those. + The entries are due between June 1st and June 10th. + You will need to supply an entry/recipe form for your entry.  I am working on making this an online form and will have that information in the package I send to you.   The score sheets should all be in the mail by now.  If you have not received your score sheets yet, please be patient as the First Round Site Directors have lives and jobs too.  If you were waiting for your score sheets in order to re-brew, you’ve probably waited too long at this point.   I hope this helps!  Good luck in the Final Round of the AHA National Homebrew Competition!