CHAPTER EIGHT
FINISHED BEER

The reward for all the diligence and hard work is a good finished product. So there is nothing more disappointing than opening a beer, after a long brew day, two weeks of fermentation, a bottling day, and two weeks of bottle conditioning, only to find it’s sub-par in some way.

It will happen to every brewer at some point, no matter how experienced or skilled. The most important thing a brewer can do is to learn from the experience, put it behind them, and move on to make better beer next time.

Because of this, it can sometimes be advantageous to become closely familiar with a beer that has gone bad, in order to figure out what went wrong. Was it your ingredients? Your process? Something that went wrong during the brew day? A cleanliness issue? Finding out how a particular unpleasant flavor is created can often be the key to preventing it from occurring in the future.

Prevention is the best cure. Once the beer is finished, it’s too late to salvage it, but there’s still plenty of time to fix every future batch.

Diacetyl is a natural by-product of yeast in fermentation. It is formed by yeast, as part of its normal metabolic life cycle. If you taste any beer halfway through fermentation, odds are there will be an overwhelmingly buttery characteristic to it. However, as yeast runs out of resources to digest in wort, it will turn to diacetyl, digesting this instead, and thereby in the process cleaning up after itself.

If a beer contains a large amount of diacetyl, it is usually because the yeast dropped out of suspension before fermentation had completely finished. Put another way, the yeast went dormant before it could finish eating. This can happen with highly flocculent yeast strains, particularly some English yeast strains. It can also happen if the beer is fermenting in a cool environment.

Finally, the presence of diacetyl may be indicative of a bacterial infection. Pediococcus, as part of its metabolic process, is known to create diacetyl and lactic acid. If, as well as the buttery flavor of diacetyl, the beer features a slight sour tang, or appears to have ropy filaments in it, there is likely a pediococcus infection.

Yeast and hops rise to the surface of a fermentation. Ending this fermentation too early could lead to an off-flavor in the beer.

Fortunately, DMS is relatively easy to get rid of. The boiling point of DMS is only 99°F (37°C) and it will become volatile during a rigorous boil of at least 212°F (100°C). Most homebrew recipes specify a 60-minute boil, though many professional brewers boil for 90 minutes to release DMS from the wort altogether.

It is also important that steam is not trapped in a way that allows it to condense into liquid that falls back into the boiling wort. A lid or a chimney stack on a boil kettle may reduce evaporation rate and water loss, but it can also collect DMS, which drips back into the kettle, making removal of this off-flavor more difficult. Most homebrew that contains DMS is due to steam not being vented properly during a boil.

DMS can occasionally be due to an infection of certain strains of enterobacter from poor cleaning or sanitation of a fermentation vessel. Be sure that fermenters are both cleaned and sanitized immediately prior to the introduction of wort (see Problems 8 and 9), that your yeast is healthy, and you have enough to start a quick, vigorous fermentation (see Problems 20 and 21).

A “cooked vegetable” smell in a finished beer is caused by the presence of dimethyl sulfide (DMS). To avoid this from happening it is essential for wort to be kept on a vigorous, rolling boil for 90 minutes.

Dark-colored glass can slow the rate at which beers become lightstruck, but only by a certain amount. Brown affords the best protection. Green glass, blue glass, or clear glass do not stop UV-B. Some large commercial breweries use a hop extract called “Tetra Hop,” which is processed to exclude the chemical that changes in light; but to homebrewers this is not easily available.

The best possible protection for homebrew is to store beer in a dark place, away from direct sunlight or fluorescent lights. Unfortunately, once beer has become lightstruck there is no good way to remove the flavor. Open containers may dissipate the aroma in time, but it will never quite go away entirely.

Dark-colored glass can slow down the rate at which beer becomes lightstruck, but light will eventually get through even brown bottles, causing skunky beer, if they are left for too long in direct contact with UV-B rays.

Most often, butyric acid is formed when a brewer allows a mash to sit for a long time at a low temperature. In some cases, a brewery may be doing this on purpose to create a sour mash (also known as a sour kettle). Some brewers mash overnight to save time and allow for maximum possible sugar conversion in their mash.

When doing so, however, all precaution should be taken to reduce the oxygen in the environment. In the presence of oxygen, lactobacillus can create butyric acid, which can survive boiling and fermentation and exist in the final product. Of course, lactobacillus is not the only bacteria to live on barley. In some cases, clostridium may also be present in grain, which, when in an anaerobic environment, can create butyric acid. However, if the pH drops quickly enough, due to the presence of lactobacillus, clostridium will not survive.

To best avoid butyric acid in your brew, finish your mashes in a reasonable amount of time (under a day, at a consistent temperature). If souring, create an anaerobic environment that favors lactobacillus growth (90°F–100°F/32°C–37°C, with a blanket of CO₂) and monitor the pH level.

Be sure to start with fresh ingredients in your mash. Spend time looking at and tasting them. Sub-par or spoiled ingredients make sub-par beer.

If you are using a municipal water source, ask your municipality for a water report and then get the water in your home tested to compare. If you are using well water, you will need to send water out to a lab for testing. If your home water is high in iron or other metallic ions, this may translate to a metallic flavor in your beer, but it may also indicate a problem with your home plumbing that should be addressed.

In some rare instances, metal pots need to be passivated or seasoned before using for brewing, particularly if you are using a pot that is not made from stainless steel. Be careful of using anything that cannot handle an acidic environment, or which might corrode in contact with an oxidative cleaner—unless properly cared for, these can release metal ions into your beer.

If you are scrubbing the inside of your pot for any reason, avoid steel wool which can leave tiny scratches in the side of even stainless steel kettles; these can allow stainless steel to pit and corrode further, damaging your kettle and possibly affecting the flavor of your beer.

Avoid using a kettle made of anything other than stainless steel. Aluminum pots are inexpensive, but long exposure to heat and the acidity of wort can break the Aluminum down and create off-flavors.

Yeasts all have an ideal fermentation temperature range, but that doesn’t mean that they can’t ferment outside of that range. If yeasts ferment at a higher temperature, particularly right at the beginning of their growth cycle, they can sometimes create a high portion of fusel alcohols. These alcohols often taste like almonds in good cases, or in bad cases like solvent or airplane glue. In all cases they can read as “hot” or “boozy.”

If using an oxygenation stone, be careful not to overdo it. Dissolved oxygen content should be right around 8 ppm, which most homebrewers can achieve in a minute or so of oxygenation with an oxygen stone. Similarly, shaking a carboy after filling it to get oxygen into solution will, in many cases, result in a dissolved oxygen of close to 8 ppm. The only way to be sure is to buy an oxygen meter, which can be an expensive proposition. In general, it is difficult to over oxygenate.

Fortunately, fusel alcohols, if allowed to age, will eventually break down into esters. However, that process can take months or even years. If you’ve made a particularly big beer and you’re happy to put it away for aging, you could be in for a treat, but in other beer styles you may just have to settle for the hot alcohol characters.

Beer can be fermented in any size of vessel. Small fermenters allow a brewer to split larger batches, and experiment with different yeasts or other ingredients.

Yeast creates CO₂. Since CO₂ is heavier than oxygen, fermentation occurs in an aerobic environment. However, once fermentation is finished, along every step of the way the possibility of infections exists. Check that your bottling bucket is clean and does not smell vinegary or sour. You may need to check or replace your bottling hoses or bottling tip. Be sure that all bottles and caps have been sufficiently cleaned and sanitized prior to using.

Some beer styles, such as Flanders Red or Flanders Oud Bruin, feature yeasts or mixed bacterial cultures that can create a tiny bit of acetic acid, which blends with the residual sweetness of the beer, leaving it with a pleasant, sour finish. However, are should be taken when using yeasts in an otherwise “clean” yeast brewery,.

The best way to avoid this is to move beer off its original yeast if it’s going to be stored in a warm place for a long period. If kept cold, yeast will go dormant instead of continuing to scrounge for resources. If left too long in these conditions, it will die but will be unlikely to lyse. In general, it is best not to store finished beer in a warm environment, for many reasons in addition to this one. If it must be done, do what you can to minimize the amount of yeast that is left in the solution before storage.

Once this flavor is in your beer, there is no good way to get rid of it. Aging may soften it, or blend it into other flavors, but if there is still yeast in solution it is equally likely that the flavor will intensify. In some high-gravity or barrel-aged beers, this flavor is considered a desirable characteristic at very low levels, as it adds a depth of flavor, but in high concentrations it can be a distraction to the overall product.

If you are not experiencing a very robust fermentation when using ale yeast, it is likely that you have underpitched it, or that the yeast is starved of nutrients. Using yeast nutrients—which are normally a mixture of dead yeast cells and zinc, and available from your local homebrew supplier—can help ensure that your fermentations are never in want of nutrients.

Lagers are not so lucky. They take a long time to ferment at cool temperatures, and often do not release gas at quite the same rate as their ale-yeast cousins do, although lager makes up for this with its long conditioning and maturation time. Part of that maturation is the oxidation and degradation of hydrogen sulfide. If your finished lager tastes overly sulfuric, it is likely that you just bottled too soon.

In the case of both ales and lagers, sulfur is something that will age out of beer relatively quickly, so long as it is not in the finished package. Once bottled, even if hydrogen sulfide does oxidize, the sulfur gas has nowhere to go. Some of it will likely off-gas once the beer is poured into a bottle, but some amount of it will always be there.

If a finished beer has been left with a sulfur-like quality, the fermentation may not have been vigorous enough. Beer should be free from sulfur before it is bottled to avoid an unpleasant “rotten-egg” smell in the final product.

Never store beer on its side. Even the best-sealed oxygen-scavenging bottle caps are porous, and will allow a small amount of oxygen to get into the bottle. If the bottle is sitting upright, a small CO₂ blanket should be present inside the bottle that will offer protection against oxygenation and oxidation. If the bottle is on its side, beer is in direct contact with the cap, which means that oxygen can penetrate the beer directly.

Keep beer in as cool a place as possible. It’s often impractical to keep an entire batch of homebrew refrigerated unless it’s in a keg, but every effort should be taken to keep beer as cool as possible, as cold temperature slows reactions.

Luckily, few homebrewers can filter beer completely clean, which means that there is almost always some amount of yeast in solution in the bottle. Yeast in the bottle can help scavenge oxygen and lower dissolved oxygen content at time of bottling, meaning a longer shelf life for your homebrew.

Beer should be stored upright to avoid oxidization and the formation of trans-2-NONENAL.

Consider heating more slowly. Most burners allow you to regulate the amount of heat being generated, and it may be that bringing wort to a boil more slowly avoids scorching. However, once the wort has reached boiling point, be sure to maintain a vigorous boil, to remove as many off-flavors as possible.

When your kettle is on the heat, even if the wort is not yet at boiling point, carefully add any sugar or extract, stirring slowly so that the sugar has time to dissolve into solution before hitting the bottom of the kettle. This will avoid any potential boil-overs. Many syrups or heavy sugars will burn on contact with the bottom of the kettle, and once the flavor of burnt malt has been introduced into your beer, it is there permanently. If possible, draw from your kettle some hot wort or hot water to add to the sugar or extract, dissolving it before adding, or preheat any syrups to make them more readily able to dissolve into hot liquid. They’ll also be easier to pour this way.

All beer needs to be boiled, but sometimes direct heat from gas flames are so hot that it’s easy to scorch the wort.

When choosing hops, consult a vendor’s website, which can provide the expected ranges of hop oils. Look out for total oil content, B-pinene (piney flavors), myrcene (piney/resinous), linalool (floral/citrus), caryophyllene (woody), farnesene (floral), humulene (woody), 3-mercaptohexanol (tropical fruit), 3-mercaptohexyl acetate (tropical fruit), 4-mercapto-4-methyl-pentan-2-one (berries, fruit) and geraniol (rosewater). There are, of course, many more oils that provide flavors in hops, but these are some of the most commonly listed and noted oils.

Make sure you match carefully when substituting hops with different alpha-acid contents (see Problem 22), particularly when substituting high-alpha hops for late additions in the boil. Bear in mind that while the beer is over 175°F (79°C), isomerization is taking place, which includes the entire whirlpool process of the beer. Consider adding late-addition hops at the end of the boil, or even in whirlpool, particularly if you experience very vigorous boils. You may be driving off the extra flavors and aromas you’re seeking.

Finally, consider dry hopping, once or a few times (see Problem 52) for added aroma and flavor. Using a blend of hops with a high oil content can add a considerable amount of depth to the flavor and aroma of any beer, not just one that’s supposed to be hoppy.

Large hop additions are very popular among homebrewers, but hops should be added with care to produce the desired balance of flavor and bitterness.

Chill haze forms when there has not been enough of a “cold break” at the end of the boil. “Cold break” refers to the precipitation of proteins that happens as wort cools from the boil. In that process, proteins and carbohydrates stick together and fall out of solution into trub. If the beer is not cooled quickly enough, or if a large amount of trub is introduced into fermentation, some of those proteins will dissolve back into the liquid and cause this light haze when the beer is cold.

To avoid chill haze, consider adding finings to the last few minutes of the boil. Homebrewers most commonly use Irish moss, which is a seaweed (also known as Chondrus crispus or carrageenan moss). It works by creating a negative charge within wort, which positively charged proteins stick to. The larger the mass of protein and seaweed, the more that gravity acts to drop them out of solution, at which point a careful homebrewer can transfer wort away while leaving all the protein behind.

Chill haze is a cosmetic problem. Odorless and tasteless, it will not change the flavor or shelf stability of your beer. As the beer ages, it is less likely to experience chill haze, as the proteins will eventually drop out of solution.

When proteins and yeast proteins don’t coagulate, and float on top of fermentation, they can lead to a hazy beer.

Specialty malts such as dark roast malts should be used in very small quantities. As they do not add fermentable sugar to the wort, high proportions of roasted malt can add dextrins, creating a more robust body, and sometimes contribute residual sugars for a sweeter beer. However, they can also contribute a lot of tannic content from the roasted husk of the barley. Since the husk on roasted barley is more brittle, it crushes more easily, which means that it has great surface area contact, and can have a much higher extraction rate. Most well-built recipes contain a very small percentage of dark roasted specialty malts with some recipes calling for as little as 1 percent of the total grist.

Some homebrewers add dark grains to the mash at the very end to extract as little of the tannin bitterness as possible, or rely on huskless roasted grains such as roasted wheat, roasted rye, or de-husked barley for dark character without tannin bitterness.

A good mash should have a pH content of around 5.2–5.4. Below that, you run the risk of extracting additional tannin bitterness from dark roasted grains. If you are unintentionally achieving a pH below 5, check the starting pH of your brew water, and consider adjusting it using calcium carbonate or sodium bicarbonate.

Dark grains are beautiful, but a little goes a long way. The burnt husk of barley can contribute tannins and harsh bitterness to beer.

The degree of alpha-acid content depends upon what field the hops were grown in, in what region of the world, how much rainfall or sunlight the hops received while they were growing, and even what time they were harvested.

It is up to the brewery to adjust the calculations in their recipe to match bitterness, based on expected IBU (see Problem 22). However, in some cases, when following a recipe, bitterness may come down to water hardness. Water with a high mineral content normally favors a harsher bitterness in hoppy beers, while soft water subdues bitterness and helps highlight malt characteristics. To achieve a certain bitterness profile through a combination of both hops and minerals, it is often easiest to start with purified water and add brewing salts to create the target hardness level.

There are multiple online calculators and pieces of software to help aid in this process, as well as to match your brewing water with that of the water in the towns of classic brewing styles, such as Dublin, Munich, or Burton-on-Trent.

When it comes to hops, there are a great variety of options available to homebrewers. As a natural product, there are also subtle variables that affect their alpha-acid content. Whole-cone hops, pictured here, are beautiful and delicate.

The root cause of under-attenuated or under-fermented beer is often yeast health. Be sure that the yeast that you pitched was fresh and not expired and that enough has been pitched. In general, when using store-bought yeast pitches, one package per 5 gallons (19 liters) per 10 degrees plato is usually a great starting point (see Problem 21). When in doubt, err on the slightly high side, or use a yeast starter (see Problem 20) to ensure robust fermentation.

Be sure that the fermenter is being kept in a room that doesn’t get too cold. Even though yeast generates a fair amount of its own heat while fermenting, a cold ambient environment can stall fermentation and cause the yeast to go dormant. Returning the yeast to a warm temperature should kick-start fermentation, though with very flocculent strains the yeast may need to be roused to get back into solution.

Finally, be sure that hops were added at the time specified on the recipe. Even beers with no discernible hop flavor or aroma need hops to help curb sweetness. Hops help beer taste like beer. A homebrewer who does not have a palate for hops may be surprised to find out just how much they rely on hops for the character of their beer.

With most problems relating to off-flavors in the final beer, a homebrewer often needs to retrace their steps to ascertain what might have gone wrong. What temperature was the fermenter kept at? When were the hops hops added to the liquid? Keeping a notebook can help with remembering these details.

Hops also contribute polyphenols to wort, which can help with both clarity and head retention. Beers with only small hop additions often suffer from poor head retention. If your recipe can handle it (or you really like hops), consider adding in some more hops to help build head retention.

Consider adding high-dextrin malts, such as Cara-Pils, Cara-Helles, Dextrin Malt, or even very light Caramel Malts, to help build body and head retention. You may also use high-protein adjuncts such as rye, wheat, oats, or even flaked barley to help build a protein matrix that can support a good head.

Finally, be sure that all soap residue has been cleaned off your equipment before brewing. Residual surfactants can cause surface tension in beer to break, which all but eliminates head retention.

All homebrewers aspire to produce the perfect-looking beer, with good head retention. Stemmed glassware (pictured) is a popular choice for beer because you can hold the stem, rather than the bell of the glass, which slows the rate at which the beer warms in the glass.

A thin body can also be the result of adding in highly fermentable adjuncts such as corn or rice, or even table sugar or Belgian Candi sugar. These additions promote fermentation and alcohol production, but do not add to the complex sugar or protein structure of the beer, which can mean a thin, somewhat cidery body.

When brewing beers with highly fermentable adjunct additions, consider mashing warmer than you normally would, or adding in high-protein grains, such as wheat, oats, or flaked barley, to help create a balanced body.

Thin bodies are most often an issue when making low-alcohol or “session” beers. To create a good, rich body in low-alcohol beers, assume a decrease in mash efficiency of about 15 percent and mash much warmer, at around 158°F (70°C). A higher proportion of barley will give you the same amount of fermentable sugars, but with the added bonus of more dextrin to help create a more robust and fuller body. Bear in mind that you should only increase base malt in this case, and that the beer may turn out slightly darker than expected.

Tulip glasses (pictured) are excellent for beer. They have a large bell to hold the beer from without warming it, and the flare at the top of the glass will support a good head while releasing aroma.

In all, it is an excellent way to find new tips and tricks, discover new styles and ideas, and share some great beer with like-minded hobbyists. They are often the best first people to give you critical feedback about your beers along with ideas on how to make it better.

You may want to consider entering a homebrew competition. homebrew competitions are often organized by style and will require the brewer to meet guidelines. Each country and region of the world has its own set style of beer guidelines that can be found either on the Internet or with the help of your local homebrew club.

Homebrew competitions give you the chance of getting the most impartial blind feedback on your beer. It will be tasted alongside others of the same style in a blind panel by a trained judge. While they can’t comment on your process, they can give feedback on the flavor and composition of your finished beer, and how well it fits style guidelines. These can be helpful learning experiences and, who knows, you just might win.

It’s not snobby or silly to smell a beer; you’re actually getting a great preview of what it’s going to taste like.