"Did I ruin my beer?" is a question that every homebrewer asks at least once. From experience, I can tell you the answer is almost always no.
The only thing that will really ruin your beer every time is poor sanitation. Other mistakes may prevent your homebrew from being the best it can be, but they usually don't prevent it from being a drinkable beverage. Still, everyone from the first-time homebrewer to the professional wants each batch of beer to be better than the last. I'll be addressing some of the common problems that homebrewers face in this troubleshooting series.
Troubleshooting Poor Head Retention:
With most styles, a thick, lasting foam is expected from a quality beer. Head stability has some impact on the texture and aroma of beer, but to me the primarily appeal is visual. If a beer looks good, I'm more likely to believe it's going to taste good. The foam on beer originates from the carbon dioxide flowing through the beer, and the stability of the head is created by proteins from the malt and alpha acids from the hops.
Poor head retention is typically caused by improper equipment cleaning techniques or simply not having enough foam-forming compounds in the beer to begin with.
The first step to correct head retention problems is to make sure you're using proper techniques to clean your equipment. Residual detergents and oils will quickly dissolve foam as it's forming. That's why you should avoid using soap on kettles, carboys, bottles, and fermentation or bottling buckets. It's just too difficult to thoroughly rinse the detergent off. Instead, use hot water and clean cloth to remove surface debris. Pick up a long brush to reach the inside of carboys, and just bend it in any shape you need to scrub every surface. If you have a particularly stubborn hop or krausen spot, mix up some detergent-free, fragrance-free powdered OxiClean and let it soak overnight, then thoroughly rinse in the morning.
It's also important to remember that your beer glass has to be clean in order to form a proper head. I always give mine a quick rinse before I pour my homebrew, just to be sure there's no remaining soap.
If your cleaning techniques are solid and you're still having problems with head retention, the next step is to increase the foam-stabilizing ingredients in your recipe. Hops that have high alpha-acid content will contribute to a lasting head. If you're making a hoppy beer like an IPA or an American Amber, then the recipe will naturally lend itself to fixing the problem.
You wouldn't want to start throwing hops into a Dry Stout just to fix an issue with the appearance. In these situations, adding up to a half pound of high protein steeping grain such as carapils or CaraFoam will increase head retention without significantly impacting the flavor. I'll often keep these ingredients in the cupboard and toss in a handful or two when steeping the grains on brewday, particularly when making beer with low hop character.
Advanced brewers have one more tool to improve head quality. If you brew all-grain recipes, then it's possible to make adjustment to your mashing techniques to coax out head-forming proteins from the grain. I'll come back to this solution in the future, after we've built up a background for all-grain brewing.
Under-carbonation can lead to poor head retention, but it's also an issue within itself. Low carbonation can cause a muddled flavor profile, especially with styles that have a higher hop character. Under carbonation brings out stale flavors, and amplifies other flavor issues resulting from poor recipe design or brewing techniques.
On the other side, over carbonation presents its own problems. It can lead to your homebrew tasting sharp and acidic. It will also cause your beer will gush everywhere when you open it, and pouring it into a glass will produce mostly foam with very little drinkable liquid.
Following the method described in my bottling post will put you on your way to good carbonation levels. One thing to watch out for is poor measurement of either the priming sugar or the beer itself. It's common to assume that you will be bottling 5 gallons of beer on bottling day, but it's often not true. Depending on how you top off your wort and your siphoning method, there it's possible there is significantly more or less than 5 gallons. That's why it's always important to check the volume of beer using the measurements on the side of the bottling bucket.
If your measurements are correct and you're still not getting good carbonation after letting the bottles condition for two weeks, it's sometimes helpful to move them to a warmer room to get the yeast more active. If you have a place in your house that stays above 70°F, that would be the best place to leave your bottles to condition. After the beer reaches the appropriate carbonation level (you'll have to taste one to be sure!), move them to a refrigerator or at least a cooler room in order to maintain freshness.
Under extreme situations, there may not be enough living yeast in your beer to produce carbonation. This would probably only happen if you let your beer sit in the fermenter for six months or more before you bottle, which isn't usually recommended anyway. If you're concerned that you don't have enough living yeast left in your beer to produce carbonation, simply pour in half a package of dry yeast into the bottling bucket when you add your priming sugar, stirring to get it distributed.
Got Homebrewing Questions?
What's going wrong with your homebrew? Leave your questions in the comments below.