The amount of beer head and its retention is a very important factor in every beer, whether it’s homebrewed or bought from a store.
Yet, not every beer style needs lots of foamy head, and depending on what gas is being used the retention may be greater or lesser. At the end of the day, it’s important for beer to have a healthy head that lasts and foams just enough for what’s appropriate for the particular style.
How long should beer head last?
Head beer should last anywhere from 1 to 10 minutes. How long will head on beer last depends on the style of beer, type of gas used, carbonation level, type of glass, and even how clean the glass is. Furthermore, ingredients such as protein from grains can increase head retention, and oils can decrease it.
When I just started brewing beer at home, sometimes my beer would have an excellent, long-lasting head but the next time it would underperform and I had no clue what was going on until I started experimenting and researching what factors affect the beer head and its retention.
Why does beer head matter?
Foam head has its purpose on every beer and while some people feel robbed when served a beer with plenty of head because it takes precious place otherwise filled with beer, others appreciate it.
Foam is good in moderation so as long as the gushing doesn’t happen straight after you remove the cap it’s very likely that some nicely formed head at the top is a sign of quality beer.
Head on a beer gives better vibes as most people expect a good beer to be also aesthetically pleasing, so it’s common that beer judges on homebrewing and craft beer competitions take this factor into consideration.
Furthermore, some styles like dark ales such as stouts and porters highly benefit from a dense, creamy head due to a better mouthfeel and other pale beers like IPAs can also add a nice increased perceivable hop bitterness through the head only.
Dry, refreshing, and often low-gravity beers like many lagers foam a lot due to moderately high carbonation levels but the head doesn’t last long and it’s there more for aesthetic purposes and a consequence of Co2 than else.
You may have also heard that foam protects the beer from oxygen which could impact the taste and keeps the Co2 in the beer by preventing it from evaporating. In my opinion, I don’t agree with the oxygen argument because oxygen can’t ruin the beer in such a short time as it needs hours to do a noticeable impact, but I can see the Co2 argument making sense.
Why does beer lose its head?
Every beer head will start decreasing after a minute, but beers with intentionally high head retention can keep the nice, dense head for up to 10 minutes before decreasing. The beer will lose its head due to the evaporation of gas which formed the head in the first place and the contact with air and warmer temperature hastens the process.
Temperature plays a big role, so in a cold environment, you can expect to lose less head on a beer than for instance, at room temperature or on warm summer days.
How much should beer foam?
1/2 inches is a minimum and 2 inches is a maximum in a pint glass for a decent ratio of head on a beer if you ask me. Some beers will form lots of foam and quickly evaporate, but if it’s intentional for a certain beer style, the beer should have a noticeable head (maybe a bit less than 2 inches) and it should stay there for at least 8 minutes.
When you enjoy a pint of Guinness, there’s always plenty of head at the top and it remains there for quite a long time. If you ever had a pint of Guinness, you’ll know how important the foamy head is, as otherwise, the beer would lose its charm and taste way worse.
Your favorite lager on another hand probably foams a lot when you just pour it (although it also depends on a technique), but after a minute it probably has a minimal foamy head and it tastes delicious and refreshing.
How to increase head retention?
I recently found a study on the effects grains have on head retention in beer, and I must say that prior to reading the study I didn’t know a few things to be the facts that affect the head retention. I’ll first state what I found in the study as it will be useful for all homebrewers and I’ll then mention other methods that affect the head retention.
1. Add more specialty and wheat malts
Heavily roasted grains such as roasted barley and black malt and wheat malts have a large amount of foam-positive components (read proteins). Adding extra any of these malts is great for head retention, so if you are homebrewing beer take this into consideration. However, bear in mind that adding too many heavily roasted grains will only fit in stouts and even then it’s possible to make the stout too harsh with lots of roasted grains.
Wheat is more fitting and more neutral, so you can fit the wheat even in recipes that originally don’t call for any wheat, but 5-10% wheat malt may provide your beer with the extra head retention you are looking for.
2. Be aware of crystal malt
For a long time, I believed that crystal malt is great for head retention and I’d always add more crystal malt than less if I had a choice. However, recently I found in the linked study above that this isn’t actually the case at all, and what’s even worse crystal malt may negatively affect head retention.
The study states that crystal malt contains low-molecular-weight foam-negative species and that it leads to the destabilization of foam resulting in reduced head retention.
I never added more than 10% in a total grid in any of my recipes because adding more than 10% can result in crystal malt taking over the other grains and causing a somewhat unpleasant sweet taste. However, now I know that I’ll be in future adding 2-3% less crystal as it’s simply not necessary to put so much crystal in recipes that are not dependent on it.
3. Be careful with oatmeal
Oatmeal contains oils and oils will greatly reduce head retention, so be careful not to use more than 10% in a recipe.
Oatmeal can be a great addition for increased mouthfeel and it will provide that beautiful silkiness that fits so well in stouts, porters, and IPAs but only in moderation!
4. Use more hops
Hops contain isohumulones which are a compound in a family of iso-alpha acids. As you may already know Isohumulones are responsible for bitterness in beer, but they also affect head retention.
Be careful not to make the beer overly bitter with hops but use them for head retention, so try to balance the high hop amount with other ingredients. Higher alcohol and fuller beer styles such as dark stouts and porters can fit more hops for better head retention without ending too bitter.
IPAs and APAs naturally use more hops, thus head retention is often pretty decent on these styles by default.
5. Pour beer using faucets
Faucets are extra equipment, but definitely a worthy piece of extra equipment.
Faucets will create pressure and send the beer through tiny holes creating tons of little bubbles which will increase head retention. Faucets work for any beer whether it’s homebrewed or commercially brewed.
If you are a beer enthusiast, investing in beer-pouring equipment is a smart decision you won’t regret.
6. Use tall, clean glasses
Tall, narrow glasses are better for head forming and retention, so sometimes a simple change of a glass shape can be the difference you are looking for. Sometimes we don’t pay attention to this when we pour beer at home and use wide glasses which can’t trap bubbles in one place and thus we come to the conclusion something else is a problem.
Furthermore, dirty glass can interfere with the foam and reduce head retention. It’s especially important to dry the glass from any detergent as it can also affect the foam and neutralize it.
7. Assure enough Co2 levels
Co2 volumes are an important factor in head forming, but also affect retention to a degree. You can’t expect much foam to form with low Co2 levels below 2.0 and thus you can’t either expect that the head will stay on the beer. After all, the head is formed from tinny gas bubbles and if there’s a lack of gas in beer in the first place, no other method will improve head retention.
For this reason, I rarely go below 2.4 Co2 levels even with stouts and porters which are considered as low carbonated beers.
Understanding how much priming sugar is needed is crucial!
8. Use nitrogen instead of Co2
Nitrogen goes great with Stouts, Porters, and even IPAs and some other ales. While Co2 is a more popular choice and certainly only accessible gas to 99% of homebrewers, nitrogen is purposely used to upgrade mentioned beer styles to a whole other level.
Nitrogen is added from the pressurized keg when the beer is ready for serving and it’s necessary to use special equipment like the faucet with extra small holes to create millions of small bubbles which form the dense head when emerges at the top. The key is to use lots of pressure and quickly create tiny bubbles with nitrogen because naturally this way nitrogen will not only create a dense head but will make it last for quite a long time if done correctly.
10-minute head retention on your favorite stout or IPA? No problems with help of nitrogen.
Bear in mind that nitrogen is never used alone and you’ll always want to mix it with some Co2 in ratios such as 80/20 or 60/40.
9. Serve at the right temperature
Gas contracts on cold and expands on warm, so if you assure the beer is properly chilled prior to serving there will be greater head retention because the foam will take longer to evaporate.
It’s important to keep the beer in the fridge prior to serving it and it shouldn’t be hurried.
Sometimes a small change in temperature can result in a way better beer experience and it really doesn’t take much to achieve it.