Foam Stability in Your Beer and How to Improve It.
Foam Stability in Beer and How to Improve It
Lace, foam, bead, head… These are all terms that you are likely familiar with if you brew or even just drink, beer. We all know foam is pretty, eye catching and something that is goes hand in hand with the aesthetics of advertising beer, as well but there’s even more to it. The amount and quality of foam says a lot about a beer: how it was brewed, conditioned and even if it was served correctly!
One of the more frequent questions we get especially with extract brewing, is “how do I improve my foam/head retention?”. Truthfully, this could turn into a very complex discussion, so I am going to give you a more straightforward explanation and a few tips to help you get the most out of your beer foam!
First, lets start with what “creates” and contributes to the foam quality in your brews. The “main” component of foam is something called hydrophobic polypeptides. So, what the heck is that? Polypeptides are long strings or organic polymers formed by amino acids which are the building blocks of proteins that tend to move up and away from liquid. If your beer is deficient in these polypeptides, this will hinder the head retention of your fermented beer. Another factor in head retention are iso-humulones, that come from hops, but more about that later, but for now, lets focus on those amino acid chains.
Where to polypeptides come from? That’s a great question! The primary source of foam enhancing poly peptides comes from the grains used in your beer. This why if you brew a recipe containing certain specific steeping grains or DME, you may see a far better quality of foam than with an extract only recipe. Extracts, especially liquid extracts, contain highly modified malts, this modification happens during the malting and extraction processes. Because these processes work to break down the complex chains, you can end up with a poor quality of head retention within the beer. Luckily, it’s pretty easy to remedy.
Steeping as opposed to mashing can be a quick and easy way boost the foam on an all-extract beer, the reason for this is the low and quick application of heat to steeping grains has a more minimal effect on the poly peptide chains found within any grain used within the steep. There are two primary proteins that make up these chains in lesser modified grains called Protein Z and LTP1. Protein Z is the most abundant within brewing grains and tend to be resistant to the enzymes that will break it down. Thus, the addition grains higher in this enzyme resistant protein will aid in creating a better beer foam. The secondary LTP1 protein is excreted during the mash and to a lesser extent, the steep. LPT1 is a shuttling protein that serves to move lipids around the membranes in barely and like protein Z, both Amino acids are hydrophobic which is an important feature when it comes to pushing CO2 bubbles to the surface on your beer.
So now that we know what components help to make those bubbles, what helps them to stay at the surface? The lion share of that duty comes from proteins called “Hordeins” that are found in barley grains. Having a good head formation and subsequently retention, comes down a harmonious proportion between proteins Z and LTP1 and Hordeins.
Earlier in this article, I briefly mentioned the role of iso-alpha acids in foam stability and retention. As you probably already know, iso-alpha acids are the bittering acids that come from hops! These hop acids also provide a valuable mechanism for increasing foam because of the reaction that occurs between the acids and the proteins in the malt.
Now that we know a little bit about the science, lets talk about how to actually put it into action. So how do we increase the foam formation, retention, and quality of an extract beer? We steep the grains that give us the highest probability of foam and we boil some hops! Some of the best grains for increasing foam are Carapils, wheat malt, and black malt just t name a few. These grains have what we call “foam positive” properties. Steeping any of these grains and also boiling even a small number of hops, can go miles in improving the quality of your beer. Just 4 ounces of Carapils malt steeped into a 2-gallon batch can really create a night and day difference even if you choose not to add any additional hops.
If you have never steeped grains, I highly suggest checking out our “Specialty Grain” recipes, as we have done the “brain” work on the foam, for you! But maybe, just maybe you’d rather “play” on your own. If that is the case, start simple with just a refill and a 30-mimute steep of 4 ounces of Carapils at 160 degrees, then remove and discard the grains before boiling the grain water, removing it from the heat and adding your can of extract.
As I mentioned earlier, the total ins and outs of foam creation and stability can get very in-depth and very complicated. I have not included every detail and potential facet of this subject, however, I have provided some of what I feel are the most important principal concepts of the subject for you as a brewer to understand. If you have any further questions, feel free to ask them in the comments or reach out to us at customer service. We are always happy to go into more detail!
I truly hope you enjoyed this and if you have suggestions for future educational articles, let us know in the comments!