Brewers are patient people, they have to be to follow this art form. However, even we stoical people get frustrated when after weeks of waiting, a beer pours with a horrendous head of foam.
Of course, how much foam we like at the top of our glass depends on where you come from. Nevertheless, head retention is a key factor in such things as beer competitions, so it’s important to understand what causes this issue.
So, what can cause a beer to lose its foam and have bad head retention?
Poor head retention in beer can be caused by either using the wrong type of cleaning product on your beer brewing equipment or having a lack of C02 flowing through the beer as well as low amounts of protein and alpha acids in the beer. The style and cleanliness of the beer glass is also a factor.
Although the amount of foam your beer has and how long it stays looking pretty at the top the glass doesn’t really affect its taste or aroma, it’s something worth investigating.
In this article, I have gone into more detail about how to identify and fix the route of your failing foam so that you can ensure a professional-looking beer every time.
There’s a right way and a wrong way to clean your equipment.
Clean is clean, right? Wrong!
Even if you are brand-new to brewing beer, you will already realize how much emphasis we brewers put on cleaning and sanitizing our equipment. It’s one of the tenants of our pastime. A bacterial infection in your beer can really ruin your entire batch and we will go to some lengths to avoid that.
However, the way that we clean and then sanitize our brewing paraphernalia is one of the most common, and easy to fix, issues with beer head retention.
The foam at the top of your beer is the result of a chemical reaction. In fact, beer foam is made from a balance between protein, alpha acid, and rising carbon dioxide. If a substance is added to that formula then the entire compound breaks down.
Using a soap-based cleaner or having residue oils in your brewing equipment can affect how well the proteins, alpha acids and CO2 interact with each other to form foam on your beer.
So, as a rule of thumb avoid any detergent-based cleaning product altogether, especially with hard to rinse items such as boil kettles and carboys. Instead, with these items remove any debris and dirt from the outside with hot water and a clean cloth (microfiber is best). For the inside, get a long stem flexible brush and scrub every inch of the inside surface, also with plain hot water.
You can then soak the inside of the carboy or what have you with a non-detergent based cleaner (ideally fragrace-free) such as Oxiclean (check out prices on Amazon). If you have the means to soak the entire carboy overnight that’s a plus. The next morning, thoroughly rinse off the items and after treating them with a sanitizer they are ready to use even if still wet.
For sanitizing I also recommend using a non-rinse sanitizer such as Star San, it’s available on Amazon so check for the best deals there. It’s so much easier than trying to use household bleach as you only need to put the surface of your brewing equipment in contact with the solution for around 30 seconds. Using diluted bleach requires you to submerge all items in the solution for up to 30 minutes, which can be a real pain with larger items.
If you are already cleaning your beer equipment in this way and are still getting poor head retention on your beer, then you may have to look to another cause.
Not enough foam-building compounds in your beer
The foam at the top of beer is a delicate balance between three components, carbon dioxide, protein and isohumulones (alpha acids). Each element of the foam comes from different ingredients in your beer. Also, some beers are just naturally foamer than others, so this is also something to bear in mind.
The main ingredients your beer head:
Carbon Dioxide is a natural by-product of the fermentation process and is present in all beers to some degree. However, after fermentation, a newly brewed beer is also subjected to either bottle conditioning or forced carbonation in a keg. The quantity of CO2 absorbed into the beer depends on how long and how well carbonation was carried out.
Protein is introduced into beer through the grains used in the mashing phase of the process. As the grain is heated starches present in it are transformed into usable sugars, but at the same time proteins are also released into the wort.
Isohumulones or alpha acids are derived from the hops we add to beer to add to its flavor and aroma. The more hops used in a beer, such as a darker full-bodied one, the higher the head retention is likely to be.
The first step is to consider how you are actually making your beer and to see if your brewing schedule is the cause of the problem. As a good beer head requires the correct balance of proteins, alpha acids, and CO2, make sure that you have all these things present in the beer, to begin with.
When it comes to proteins, they are a blessing and a curse. Although we want them in our beer to give us a lovely heady foam, too much can lead to a cloudy beer. (see my full article on what other things lead to an overly cloudy beer and how to fix it). You can control the level of protein in your wort during the mashing phase if you are following an all-grain recipe.
Carrying out a protein rest around the 122-140 °F (50-60 °C) range can be the cause of poor head retention later in the beer’s life. In case you aren’t familiar with this technique it merely means keeping the wort temperature at 122-140°F for around 20-30 minutes to allow enzymes in the grains to work on proteins and break them up to avoid a chill haze developing later.
So, if you are carrying this out when not using large amounts of unmalted or flaked grains such as wheat, rye, and even oatmeal, you may be killing off your head unnecessarily.
However, if you find that the issue is not due to an error in your brewing approach, then the problem may still lie with the ingredients you are brewing with.
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How to choose ingredients to enhance your beer’s head
As the balance between such things as malted grains and hops can really affect the overall finish of your beer, altering them for better head retention can be a challenge. Over-using one ingredient for better foam could really hamper it in another area, so proceed with caution.
Head enhancing malts are rich in proteins and dextrins which will help build your beer’s head in the glass. However, when you use too much of these types of malts, as well as flaked barley and wheat, you run the risk of more intense tannins in the beer and lower overall clarity. Grain which best improves beer foam is known as crystal malts and dark malts. Experiment with light Carapils, Carafoma and also Caramel malts.
The Isohumulones or alpha acids in hops are also an important ingredient when it comes to good head retention. However, don’t just chuck in extra hops without considering the overall balance between bitterness and sweet in the beer. Personally, I love the bitterness of a good English ale or face scratching IPA, but it’s not for everyone. So, it may be better to source hops with a higher alpha acid content and use it in smaller amounts rather than doubling your hops bill with hops containing lower levels of alpha acids.
When carbonating your beer there are two main avenues to follow. Either bottle condition it by adding priming sugar to each individual bottle of beer and allow residual yeast in it to carbonate the brew. Alternatively, you can rack your beer into a keg and then pressurize the container with CO2 and allow the beer to naturally absorbed it over time.
As the amount and duration of your beer head rely on the rising bubbles of carbon dioxide, flat beer isn’t going to produce a foamy finish. So, it’s important that you have primed your beer correctly when bottle conditioning and waited long enough for carbonation to take place.(I go into more detail in my article on bottle conditioning here). Also, you must use the correct PSI when force carbonating and serving your beer from a keg. Check out my article on how to carbonate your beer in a keg here
If kegging, then you can also try to mix of carbon dioxide and nitrogen in your keg, especially for serving the beer. While CO2 dissolves readily in your kegged beer, nitrogen forms larger bubbles and isn’t as easily introduced into the beer. This makes for a great base for building foam and this is why many commercial brands, such as Guinness, use this type of mix. (buy beer from local breweries)
Depending on the beer you have and the mix you want to go for (25% CO2, 75% N2 for stouts – 60% CO2/ 40% N2 for lagers and ales) you may or may not need a separate gas tank for the nitrogen. Generally, lower levels of a carbon dioxide and nitrogen mix don’t require an additional gas cylinder or tap system.
Head retention additives
If you have racked your brain and tried every combination of ingredients you can to no avail, then you may want to consider adding something to your beer to get that perfect head.
This being said, for most brewers, this simply won’t be necessary unless you aren’t using 100% malted barley and wheat. If you are using rice or corn for your grain bill, then head over to your local brewing shop and pick up what they call ‘heading agents’.
Be aware that some of these compounds need to be added to the beer during the bottling phase and others will need to be added before fermentation. Generally, all these types of agents will soften the character of your beer and thus affect the taste to some degree. They are usually inclusive of iron salts or gums or alginates.
If you are using any other ingredients other than grains, hops, yeast, and water (known as adjuncts) then these additions may also have negative effects on your beer’s foam potential.
Things such as coffee, chocolate, fruit peels, and even oats have a fat content that can work against the proteins, alpha acids and CO2 when building head.
Make sure that you give your brew time to settle so that all of the additional compounds can sink to the bottom of the wort after brewing. Then, make sure that you leave this ‘trub’ behind when racking your beer. In this way, you can limit the adverse effect of these ingredients on your head retention while enjoying their aroma and flavor in the beer itself.
Your beer glass is letting you down
Another very common and often overlooked issue in beer head retention is the glass you are drinking from. Although as brewers we are often very concentrated on the quality of our brewing techniques, we can often be too laid-back about what we serve our beer in. I’m as guilty as the next person, drinking my beer from bottles instead of out of a glass on a regular basis. What a barbarian!
The correct glass for the job
Sadly, not all glasses were created equally. The most common glass for most of us is the US Shaker or European Nonic Imperial Pint. But, these glasses don’t always do our beers justice.
If you are drinking a light beer which has a low carbonation level then having a very wide-rimmed and shallow glass such as a Belgian goblet will not help you with head retention. Rather you need a long and tall glass with a lip to help keep that head up for as long as possible.
In the same way, if you have brewed a very highly carbonated Belgian style beer, then serving it in a regular Shaker glass with probably lead to inches of foam before you get a sip of beery goodness. Again, here we need the right glass for the job and this beer needs a wide-rimmed glass with a shallow squat body to allow gas to escape while also forming a healthy head.
For more details on exactly which glass you should be using for which type of beer (and why) check out my full article on glasses, taste, and head retention.
A dirty or soapy glass
As with your brewing equipment, if your glass has any impurities in it or has oil or soap still hanging around, then it may not help foam to form.
Just like your equipment, try to wash your glasses straight after use and only with warm water and a clean cloth. If you do use soap or a dishwasher, then make sure you rinse the glass 3 or 4 times in warm water to really remove any trace of detergent or grease.
Serve at the right temperature
Another issue that some brewers have is not serving their beer at the correct temperature. Warm or overly cold beer will not be at its best and this can also be a source off poor head retention. Most refrigerators actually keep your beer at slightly below the correct temperature, so it’s a perfect excuse to give your partner for buying a dedicated beer fridge which you can change the thermostat on without ruining the rest of your food.
As a general rule of thumb, don’t pour that beer if it’s colder than 44°F (7°C) for an Ale, colder than 42°F(6°C) for a good lager or 55°F(13°C) for a stout. Some barleywines of ages stouts and ales can be served at room temperature.