Nothing ever goes as planned. Or at least that’s how it sometimes seems in brewing. For the most part, with proper planning and attention to process, your brews will turn out as expected. However, things can go wrong, or sometimes they just go … different. Part of the fun of brewing is learning to understand and appreciate that not all of your troubles are necessarily a bad thing. Occasionally I’ll have a brew that just turns out undrinkable, but often it’s just different than I expected, or something that others like more than I do. This section is meant to help you troubleshoot some of the more common problems in brewing. There are many other subtle surprises that may or may not be problems. Read up, visit forums, and talk to other brewers when something problematic comes up that you don’t find the answer for here.
Ferment Is Slow or “Stuck”
There are various factors that can cause a slow or weak fermentation. The usual suspects are: aeration, temperature, and water. Be sure to “splash” your wort by pouring it vigorously into the fermentation container, as this will help introduce oxygen important for yeast to thrive. You can also stir it vigorously with a long spoon. If there is no visible fermentation 24 hours after you’ve added yeast, try aerating again either by stirring or by pouring into a clean bucket and back into your fermenter. If you still get no fermentation, it could be because you either didn’t use a viable yeast or didn’t pay enough attention to the other two factors.
Temperature is a vital factor. Most yeasts, particularly ale yeasts, ferment best in a warm area, preferably no cooler than 70°F (21°C) and not much hotter. Fermentation will proceed faster in hotter temperatures, but this can also produce additional qualities you may or may not appreciate. Typical flavor “qualities” of a hot ferment are fruity, solvent-like (fingernail polish—yum!), and wine-like flavors. Use whatever method works best for you in a home environment to ensure a warm, but not too warm, environment. In cooler seasons, set the fermentation container near a heat source (but not too near) and rotate it occasionally to ensure even heating. Don’t set the container directly on a cold floor, and wrap it with a blanket or sleeping bag to keep it cozy. In the summer position it where it won’t cook. If you don’t use air-conditioning, this can be tough. You may need to move it to different locations during different times of the day, but don’t stress this too much. Just be sure it’s kept from overly cool temperatures.
The final culprit, which can be the most frustrating, is water. Generally if you use tap water, all chlorine will dissipate with boiling. Some ferments, though, don’t require boiling. Be sure to boil your tap water (even if it’s filtered) before using it for a low-to-no-heat ferment, or be safe and use springwater. Also, take care that your water source doesn’t have chloramine (see chapter 4). If you just can’t get your wort to ferment, let it sit for a day or two (or as a last resort, bring it to a brief boil and cool it to the proper temperature), and pitch more yeast.
Poor Mash Yield or Set Mash (Slow Wort Runoff)
Unless you’re an ultra-super-awesome brewer, you’re rarely going to get much more than 80 to 90 percent efficiency in your mash yield. You want to draw as many sugars as you can from the malt without over-sparging, which can potentially lead to a husky, astringent flavor. I always keep honey, malt extract, or in some cases cane sugar on hand to help bring my gravity up if I don’t get a great yield. Some possible culprits of poor mash yield are:
Possible culprits of set mash are:
When you’re working with all-grain recipes, you can only do the best you can do. Whether you’re just starting out or have a few batches under your belt, try not to get frustrated. There are a lot of rewards to all-grain brewing, but there are also a lot more avenues by which things can fail to go as expected. This is coming from someone who often gets frustrated (likely unnecessarily) because I simply can’t control things as much as I’d like. Practice lots of patience, and don’t be afraid to cheat to make sure you end up with your ultimate goal, a tasty batch of brew.
Funky Flavors
The list of possible off flavors or aromas is fairly long and, as referenced previously, depends partially on individual taste preferences. I highlight a few here. Research further if there is a flavor you just can’t figure out, or simply enjoy the idiosyncrasies of your brew.
SOUR
The most obvious culprit is lactobacillus contamination, but it’s often hard to pin down exactly how it occurred. Cleanliness problems are the first place to check. Modern brewing dogma would tell you that you didn’t sanitize well enough, but I would say that perhaps some of your equipment wasn’t cleaned well enough. Again, it’s hard to say with this one. Some of my brews where I’ve avoided using hops or other preservative botanicals go sour if not drunk fairly quick, as do some of my fruit and vegetable brews. Wish I could offer you a more clear solution for this one. Enjoy it as best you can, blend it with something else, and take extra care the next time around.
GOATY, BARNYARD, OR SWEATY SOCKS
None of these flavors sound particularly appealing, but in small amounts they can actually add to the complexity of a good brew. If it’s just too much, this is another likely victim of lactobacillus contamination.
BUTTERY
Diacetyl is a chemical that is used to imitate butter flavors in processed foods. It can occur naturally in brewing and is an expected flavor for some styles. If you get it and don’t mind it, don’t worry about it. If you don’t like it, give it some time before opening another bottle and it may dissipate. Some yeast strains and even malts will naturally produce this flavor, as will fermenting at warmer temperatures.
SKUNKY OR RUBBERY
Anyone who has traveled to Europe and enjoyed a beer there and then had the same beer at home (usually bottled in a green or clear bottle) knows this flavor. For instance, I enjoyed Heineken a great deal when I visited Holland but just can’t get into it in the States. You will experience the same disparity in your brews if you let them become exposed to sunlight or even fluorescent lights after bottling. I haven’t noticed any problems from brief exposure to fluorescents, but the best solution is to bottle primarily in dark brown bottles.
CIDERY
Not really a problem in my book but maybe a flavor you don’t want in all of your brews. The common modern homebrewing maxim is that too much corn sugar or cane sugar will impart a cidery flavor, which is true. That’s no reason to not use sugar as an adjunct, or the primary sugar source, though. Most simple ales will produce this flavor, I suppose, though I’m not sure I would describe a lot of my simple ales as cidery (although I have received comments that some of them have a nice fruity profile, even though I used no fruits). I’ve made grain-based beers where I got poor mash yield and used a substantial amount of sugar to compensate that turned out to be unique, quite flavorful beers.
Priming Problems (Under- or Over-Carbonation)
See Bottling and Priming for Carbonation in chapter 8 for information on priming. Priming problems are pretty simple to identify, and can in most cases be corrected, or at least put up with. Keep in mind first that many traditional beers, sahti for example, are drunk flat or very lightly carbonated. You may want to intentionally drink them this way to be authentic—or if a beer comes out a little flat, congratulate yourself on drinking a historically authentic beer. Overpriming and underpriming essentially come down to problems with too much or too little priming sugar, but this isn’t always the case.
If you open a beer and it gushes or foams excessively, you likely either used too much sugar for the style and gravity level of the beer, bottled before fermentation was complete, or both. There’s no real solution to this, other than opening each bottle very carefully, preferably outside (I would say over a sink were it not for the gusher I had once that shot straight to the ceiling), and with a glass on hand to carefully pour the brew into. If all of the bottles gush, try to finish them up as soon as possible, opening each with a towel wrapped around in case of explosion. If only some of the bottles gush, you likely had some residue in your bottle. When saving bottles for reuse, always be sure to clean them thoroughly directly after use, as dried residue can be tough to get out.
If your beer is flat or nearly flat, there are a few likely culprits:
I’m fully aware that most of these solutions sound like a real pain when working with, say, 50 or so bottles of beer—particularly when it’s hard to tell which of the above issues is the culprit. I generally don’t worry about it and take steps to avoid similar issues with future brews. One thing I’ll often do if a beer doesn’t have the level of carbonation I desire is to take a similar beer or one with a complementary flavor that has strong carbonation and simply blend them in a glass.
Haze
If the beer is a bit hazy and that bothers you, don’t look at it or drink it from an opaque vessel. In rare cases haze may affect flavor, but there are likely other issues involved. When judging beers, haze is considered an issue depending on the style, but I don’t concern myself with it. Most homebrews will have some degree of haze due to various factors. You can add gelatin or isinglass when priming to avoid this, or invest in a beer-filtration system. Or just have a drink and enjoy the haze.
Mold or Other Growths
Generally, if you follow strict cleanliness procedures, you won’t experience any actual mold, particularly if you’re fermenting primarily in an anaerobic/closed-container environment. Fermentation foam (krausen) forms a protective layer that keeps out contaminants during early stages of fermentation. As fermentation progresses, particularly if you have left the beer in its fermenter for several weeks, you may see a thin white film, or pellicle, form on the surface. This is a good sign, and should be left alone. This is a strain of yeast, Brettanomyces (see chapter 5), referred to by beer brewers as “the Brett” and by vintners as “Flor” (flower). Leave it alone and simply stir it in when priming. Although Brettanomyces can be intentionally added for a souring effect, I’ve had pellicle show up in a few beers and meads, and none have gone sour that I didn’t intend to go sour.