Hi there, new here? Welcome to slow pour, home of the foam :) Let’s get you caught up! Sometimes we get the question, “what’s with all the foam?” Beer foam, or as the Bavarians call it, ‘die Blume’ which translates to “the flower”, has been a topic of debate across all corners of the beer-consuming universe probably since we first sucked the rotting juices out of a loaf of bread, mmmm juicy bread.

“Ok so, what is beer foam!?”

Well, foam is produced from the bubbles of gas in beer. This gas (carbon dioxide aka CO2) is produced during the fermentation process, and in today’s modern brewing world, also introduced during the post-fermentation process, where CO2 is injected into the resulting beer liquid (this is called force-carbonation when the beer liquid is pressurized with CO2 in a confined space). That means when a beer is opened or poured into a glass, the gas bubbles react to the resulting pressure differential* and rise to the top and create a foamy layer full of goodies like protein, yeast and hop residue. Scientists, and know-it-all beer nerds, call it ‘nucleation’. In any beer, there are large protein groups and small protein groups, which both act as foam aggregators (“foam creators”). Lipid Transfer Protein 1 (LTP1) are proteins commonly found in the malted grains used in the production of beer. Yeah, even that one. These LTP1 proteins hate water (also called hydrophobic. Kind of like your favorite cat, Bandit. Try to bathe her and see how quickly and vigorously she tries to escape the water’s cruel, cold hands) – so, to get out of a glass of your favorite barley liquid the only way is up and out. In order to catch a lift up to the surface, they latch on to the carbon dioxide bubbles and travel up to the surface with the bubbles. These proteins congregate in a coating around the bubble and as result, maintains this “foaminess” that we all love to see. The hops also play a role here to solidify the foam to a cloudy coating with the help of iso-alpha acids*. The amount of LTP1 found in a beer can be influenced by the climate from which the grain was sourced; as well as every brewing process along the way, from mashing, to boiling, to fermentation as the LTP1 proteins are modified and impacted from these processes. All of these steps will have an impact on the final foam’s taste, texture, quality and retention of the beer foam. ie. foam needs a high quality brewer with high quality grains to help make its way to your glass. Thus, foam is often a sign of high quality beer!

“Ok, I'm no science whiz, I guess what I’m saying is why should I care about foam when it comes to drinking my beer?”

Well, simply put, foam is flavour. Foam is a critical component to all aspects of enjoying a beer. It adds a soft, pillowy mouthfeel component to your experience of a beer; Guinness is a good example of this, though technically a different style of foam. Without this component your Guinness would be unpleasant. Foam also contains many compounds in it that contribute to taste and aroma. By creating well-developed foam (remember this phrase for later) you ensure that all these components make their way to your palate. The creation of foam also slightly reduces the overall carbonation of the beer, making it a more pleasant experience to drink. With some of the CO2 taken out of the beer you get to experience the malt profile a little better and this balances itself with a more bitter foam. Foam also has antioxidant properties (not the, “I’m going to turn a new leaf over and eat kale with every meal antioxidant properties), meaning it inhibits oxidation. If you don’t know, oxidation is the enemy of good beer. When oxygen is absorbed into your favorite beer liquid it reacts and creates flavors reminiscent of cardboard or wet paper. GROSS. Thus foam protects your beer like Gimli, son of Glóin. Also, very simply; beer with foam just looks better! This is the part where I restate my thesis statement - foam makes beer better.

“So now that we know why foam is important, how is foam made?”

Easy. You pour a beer into a (clean) glass. The worse you do it the better. No, seriously. Remember we talked about all the goodies that attach themselves to CO2? Well, it’s not that easy you see. Think of foam as the Rabbit Hill ski slope rating system. If you are like me and can’t get past the Bunny Hill, then you aren’t going to see what lies beyond the banks of the beautiful North Saskatchewan. If you can bravely slalom down the black diamond (impossible), then you’ll be able to catch a glimpse of the even more beautifuler Henday. Make sense? The harder the pour the better the view of the Henday. I think I’m mixing up metaphors but you get it. If you pour your beer soft and gentle you won’t send the bat signal to our friends, the LTP1 proteins. I don’t know about you but I’m getting serious Magic School Bus vibes right now. What you’ll get is a thin layer of bubbles (bubbles, not foam, this is important) that may stick around until the credits roll but are definitely not waiting until the secret scene at the end. Spoiler alert: there is going to be a sequel.

*the higher the foam, the closer to god*

What you need to do is pour with some vigor. This is a clear signal to our homies, LTP1, that it’s time to roll out Autobots (I am so bad at linking metaphors together. I’ll stop.). These proteins thoroughly cling to the CO2 bubbles on their way up to the surface. This is how foam is made. Proper foam. You can tell by how tightly packed the bubbles are, oftentimes it’s difficult to see individual bubbles. Silky smooth, reflecting the light differently. This is how we know the hop residue and protein goodies Escape from LA (Remember that movie? Steve Buscemi in his prime. Ok, that was the last metaphor promise). This is the aromatic, long lasting foam we need for properly good beer. See I told you there was a difference.

“Ok I’m starting to understand now. One question, when I get my Pilsner Urquell, the foam looks different then the other beers you pour? How come? ”

Now we are getting somewhere! The foam you get with your Pilsner Urquell is what’s often called “wet foam” - that is dense, beer saturated foam. It almost has the appearance of milk. PS: yes that’s where the Czech-style of pour, Mlìko, comes from! This foam is created using a mesh screen located in a Czech Side Pull Faucet. We will save faucet talk for another blog. This foam is sweet, creamy, dense and delicious and is the only type of foam that belongs on a Pilsner Urquell. So I guess that makes the foam we were talking about earlier, “dry foam”? Sure! Why not? It is certainly less saturated. To be honest, there isn’t a whole lot of literature on the etymology of foam types and genesis. Like any good obsession we need nerds to deep dive, create different universes, find connections and discover history and lore. From there we will have a family tree of foam and then it will eventually become the subject of NY Times Crosswords. 4 Down: 3 letter word for the type of dense, beer saturated foam found on your Pilly…

*three fingers of foam. also please ignore how out of focus this is thx*

“OK, but you never answered the original question though, why so much foam? ”

That’s a great question, thank you for asking. A lot of that question is a matter of perspective, no? We need not look past Pilsner Urquell (our only mainstay at SP, and an inspiration) to see why we have chosen the path that we have. If I was behind the counter at a local Czech pub and poured someone a glass of Pilsner Urquell with a thin layer of foam barely a fingers width in depth, they would probably exclaim, “why so little foam!?”. I would wager to guess that no one cares more about foam than the Czech people. Having recently traveled there and toured many local pubs and breweries it is apparent that foam matters as much as the beer itself. There is no beer without foam. The art of pouring a beer in Czechia is exactly that, an art. It’s something you train and learn and discuss. It is a profession. When thinking about how we would dispense our beer at Slow Pour, we wanted to offer the same seriousness. To quote Ashleigh Carter, Founder of Bierstadt Lagerhaus and major inspiration for us: “We wanted to change that idea of how to present beer and make it special again.” So to answer your question, in our eyes it’s the right amount of foam!

Oh, and it’s not just a Pilsner Urquell thing, every well meaning bar you go to in Czechia will pour you “three fingers of foam” even if it’s not in a Czech-dimple glass!

“Aren’t you afraid of sounding pretentious though? ”

Well, It is our job at Slow Pour to execute the brewers’ intention. It’s the job of anyone dispensing beer made with passion and craftsmanship. Just like there is craftsmanship in making the beer, there is craftsmanship in pouring the beer. You can forget every word you read just now, you don’t need to know or worry about all these details. What you should take away is that Slow Pour takes the small things seriously and that you will find good beer here the way it was intended :)

fin.

-sp

why so much foam?