Good post. I've never thought about licking a plaster before I don't like phenols at all but cloves in moderation I can stand as I find the two different.
It is that TCP taste I dislike. Don't plasters taste like Germolene? Can't say I've ever really noticed this one at all in beer. This is an easy one to detect, albeit in my experience less common than some other faults.
TCP is a disgusting taste in beer, at least but I'm amnazed that some brewers python dark theme to believe there is anything wrong with it.
Btw, I think you should keep an eye on "Claudia Becks" and her not-so-subtle marketing agaenda. Neil - Think of it like the way plasters and hospitals smell.
That over-clean aroma. Or, take a plaster and give it a chew! Tandleman - I'm with you and as long as you know which is meant to be there and which isn't then it's fine. I'm still not a huge fan of strong cloves though, even if it should be there, but that's just personal preference. Barm - Nope, just trying to learn more! Tyson - It's not a common one, thankfully. I did have a few beers from one brewery recently which were all affected by it, which was a shame. Some people really hate phenols.
I generally love them in stouts. In pale beers they can be a little more difficult to cope with even when they are supposed to be there. Another drinker tried the same beer and declared it tasted like a factory full of marker pens. I've picked this one up before, but not realised what it was. It always makes me think of the old Beechams Powders sachets. Surely, you've omitted the biggest contributor of phenolic tastes in beer?
Having said that, it's a moveable feast: I had a beer that was horribly infected, nasty TCP phenolic taste albeit a flavour I am strongly sensitive towhich I thought 'well I'll just leave that alone'. Welcome to the weird world of beer! Just got a phenolic beer and I'm fairly sure its unintended. I quite like it though. Just opened a Green Jack Baltic Trader.
Vikki's first tasting note? Quite suits a big stout though, nicely balanced with a dry finish. I've had it in some pale beers where it can be really offputting, but like you say is a common characteristic in wheat beers and one of the flavour profiles I quite enjoy in the style. Friday, 24 June When beer goes bad: Phenolic. Plasters, Islay whisky, TCP, smoke, clove; very few beers should taste like this.
And this is another off-flavour which some people are more susceptible to tasting than others. Peated malt will also have this flavour but it will often add a different character more along the lines of charred toast than TCP. I also sometimes taste it as flinty or like concrete.Dave Carpenter May 10 - 5 min read.
Esters and phenols are organic compounds that contribute to the aroma and flavor of many beer styles. For starters, here are the technical definitions which are probably only meaningful to the chemically curious :.
A phenol is an organic compound in which a hydroxyl group -OH is bonded to an aromatic hydrocarbon ring also called a benzene ring. Therefore, I propose a slightly different definition. Broadly speaking, esters are fruity and frequently desirable, while phenols are spicy and usually unwelcome. Esters are very common in beer and are formed when an alcohol and an acid react in a process with the highly original name esterification. Esters can be desirable in certain amounts in certain ale styles, or they may be considered off flavors, especially in lagers.
Aromas and flavors attributable to esters include. Because ester production increases with fermentation temperature, ales generally express greater ester character than lagers.
Other factors that can affect ester production include fermentor geometry, wort composition, and yeast selection. While style-appropriate esters are usually pleasant, phenols are almost always off flavors. Phenols are associated with the following characteristics:. The same Bavarian yeast strains that give Hefeweizen its signature banana character also create clove-like phenols. Tannins, also known as polyphenols, deliver an astringent, puckering sensation to the palate.
Smoky flavors can come from smoked malt, of course, but they can also arise from bacterial infection. And sweaty horse blankets are simply normal by-products of certain but not all!
Belgian Trappist ales and saisons are excellent illustrations of phenols positively contributing to beer character. Speaking of chlorine, the chlorine in treated municipal water can react with phenols to create chlorophenols, which have a flavor often described as adhesive bandage-like.
Want to learn more about brewing water and mash chemistry? As with most beer characteristics, the best way to learn about esters and phenols is to sample examples that are notably estery and phenolic. Then you can populate your own mental ledger with the images that make the most intuitive sense to you.
Next Up:. Lautering and Sparging.You are using an outdated browser not supported by The American Homebrewers Association. Please consider upgrading! The fact of the matter is, esters and phenols are quite different, though they can be present at the same time. During fermentation, a reaction between organic acids present in the wort and the developing alcohol cause esters to form.
Common aromatic ester characteristics include banana, pear drop, apple, honey, roses and even solvent-like in some instances. While the reaction between the acids and alcohol actually form esters, three variables influence the amount of esters that can potentially develop. By understanding and managing these variables, homebrewers can have a certain level of control over the character and level of esters produced.
High concentrations of sugar, zinc and free amino acids tend to promote higher ester levels. Higher levels of dissolved oxygen and lipid content can inhibit ester formation. Some yeast strains are more inclined to produce esters.
Generally speaking, ale yeasts produce more strains than lagers, but this is likely mainly do to the warmer fermentation temperatures. Believe it or not, the shape of the fermenter can impact the production of esters. Tall, narrow fermenters tend to produce lower levels of esters than shallower, more open vessels.
Fear of Phenols
This is because high hydrostatic pressure and levels of CO2 in the tall, narrow vessels inhibit ester formation. In most cases, phenols are not desirable, but there are some exceptions for certain beer styles. Phenols are detectable at very small concentrations and tend to show up as clove-like, medicinal or smoky aromas.
Volatile phenols are generally derived from three different sources. Water can often times contain phenols that are transferred to beer, which are not eradicated during the boil. Smoked malts, like rauchmalt and peat malt, add phenols that impart smoky, earthy notes reminiscent of a camp fire.
When brewing smoked beers, these phenols can be desirable. Hops and malt also are a source of polyphenols in the form of tannins, which are perceived more through sensation then smell. Chlorine and bromine tend to encourage high levels of phenols and polyphenols. Chlorine is common in water, which can be treated before brewing to remove.Follow RSS Email. This week we explore the problem of phenolic and tannin flavors in beer.
Phenolics are usually considered an off flavor, though in some beer styles they may be desirable at low levels. Phenolics cause some confusion because they can introduce a variety of flavors to home brewed beer which vary from clove and banana at the low end to spicy or smoky flavors or even medicinal or band-aid like flavors in the extreme.
In certain styles, notably German weizens and many Belgian beers the clove flavor can be desirable, but in most beers phenolics are considered a flaw.
Phenols or phenolics are chemical compounds similar in chemistry to alcohols though not alcohol that tend to be highly acidic. In fact some phenols are actually used as cleaning agents. They come in many varieties polyphenols, chlorophenols, etc…which is why they can drive several different off flavors in beer when present.
Phenolics are naturally produced by many yeast strains during the fermentation process, with some Belgian, German and British yeast strains being higher level producers.
Another common source of phenols are wild yeast strains, which often contribute band-aid like flavors. Because phenolics are produced by most yeast strains, they are present to some degree in any beer. However several key points in the brewing process and ingredient selection can drive how bad your phenolic problem will be in the finished beer.
First, the use of chlorinated water for brewing is a bad choice. If you have water that is highly chlorinated, the chlorine will react with naturally occurring phenols in your beer and produce chlorophenols which have a very low taste threshold and are instantly picked up as a flaw when tasting.
Chlorophenols manifest themselves in the finished beer with a strong band-aid or even diaper aroma and flavor. Even if your regular tap water is relatively free from chlorine, you need to be aware that most US water sources are flushed about once a year with higher levels of chlorine to purge the system.
If you happen to brew during that week, you may get a strong band-aid flavor. Using bottled RO water is a good alternative. Finally if you use chlorinated cleaning agents, such as bleach, you need to be thorough in rinsing your equipment before use as this can also introduce chlorine to the beer.
Another form of phenol is called polyphenols, which are more commonly called tannins. Tannins polyphenols tend to manifest themselves as an astringent or bitter flavor in the finished beer, and may also lead to a permanent haze or chill haze haze that shows up when the beer is chilled.
Tannins can be extracted by oversparging continuing to sparge too long when mashingsparging at too high a temperature greater than F or 77 Cor mashing at too high a pH level.The dreaded precursors to chill haze and contributors of off-flavors and astringency, common phenols also play many beneficial roles in keeping beer fresh, colorful, and balanced. This article explores the simple tricks needed to control these complex compounds. Most brewers regard, phenolic compounds with strong suspicion.
Tannins are the most widely known class or phenols and are usually avoided as potential sources of bitterness, astringency, and haze. Other negative phenolic effects such as medicinal flavors and infection by-products also contribute to the fear and loathing.
In small concentrations, phenols can contribute subtle, but important, flavor characteristics to beer. These highly reactive compounds can also act as antioxidants that prevent other, less desirable reactions such as staling. Understanding these varied contributions and the means of controlling them is an important step in quality brewing. This article reviews the chemistry of phenolic compounds, describes their various contributions to finished beer, and provides guidelines for successfully managing both ingredients and brewing processes to help ensure that you get the beer you want from your efforts.
In fact, the impact of their presence is remarkably common. Phenols are organic compounds based on the common elements carbon, hydrogen, and oxygen. These simple carbon rings are called aromatics because many of the compounds they form have very strong odors. The rings are quite reactive, joining readily with other compounds, and thus they are commonly found in nature. Plant tissue is the major source of natural phenolic compounds and the only source relevant to brewing.
These compounds play several roles in plants. For one, the phenolic compound lignin stiffens the cellulose walls in higher plants, and these cellulose walls in turn act as structural elements. Lignin is present in the woody tissues in hop bines and barley straw, for example, and to a lesser degree in barley seed husks and hop cones.
Some phenolic compounds also act as plant colorants, providing red, blue, and purple coloration. Yet other phenolic compounds have antimicrobial and antifungal activity, and cereal plants such as barley even increase their phenolic content in reaction to attack or tissue damage.
Bitter phenolic compounds provide a defense mechanism in plants, rendering them inedible by herbivores. Some evidence even suggests that phenolic compounds act like animal hormones, regulating development and controlling germination and growth of the plant. Researchers have identified 67 basic phenols and several hundred phenol complexes in beer. The vast majority of these phenols can be classed as polyphenols, complex chains of simpler phenol building blocks.
Monophenols, despite their simple-sounding name, do not exist freely in plants, but instead often bind to particular sugars; ferulic acid, for example, can form compounds that give estery, clovey notes to Weizens.
Flavanoids, though also referred to as biphenols, are actually thought to form from a single monophenol by a series of complex reactions. Flavanols and catechins are examples of flavanoids that play a role in brewing.
Like the monophenols, these molecules generally bind ro sugars, but these flavanoid—sugar bonds ether bonds break under very different conditions in the brewing process. To understand these processes, we need to step back for a basic chemistry lesson. The phenol building blocks: The building block of phenolic compounds is a six-sided ring of carbon atoms with at least one attached oxygen and hydrogen molecule called a hydroxyl group.
As mentioned above, this simple six-sided ring is also known as an aromatic ring because many simple chemicals with this ring structure have strong aromas. Monophenols: The simplest monophenol is known as benzenol because of its benzene-like ring or carbolic acid and has the chemical formula C 6 H 5 OH.
Monophenols with a single carbon atom added to one or more of the ring carbons are commonly known as benzoic acids.
Benzoic acids are common in plants including barley. C6—C2 phenols are rare, but C6—C3 phenols are common and appear in two distinct forms: Those with a straight carbon chain are called cinnamic acids, and those that form a secondary ring containing oxygen are called coumarins. Monophenols are not free in plants; they are often bound to sugars, organic acids, or to other larger phenols such as lignin. Specific monophenols may bind to particular sugars, such as ferulic acid, which is often found attached to the sugars arabinose or xylose.
The sugar molecules generally are not free either, but are part of the cellulose structure of a cell wall or part of a starch molecule. Monophenol-to-monophenol bonds are progressively broken as the pH increases above 5 or so.Wheat beer is a beerusually top-fermentedwhich is brewed with a large proportion of wheat relative to the amount of malted barley.
Belgian white beers are often made with raw unmalted wheat, as opposed to the malted wheat used in other varieties. In Britainwheat beer is not considered traditional; however, sales have increased in recent years. This is in line with the rising sales of other speciality products.
It is well known throughout Germany, though better known as Weizen "Wheat" outside Bavaria. The Hefeweizen style is particularly noted for its low hop bitterness about 15 IBUs and relatively high carbonation approaching four volumesconsidered important to balance the beer's relatively malty sweetness.
Another balancing flavor note unique to Hefeweizen beer is its phenolic character; its signature phenol is 4-vinyl guaiacol a metabolite of ferulic acidthe result of fermentation by top-fermenting yeast appropriate for the style. Hefeweizen' s phenolic character has been described as "clove" and "medicinal" "Band-aid" but also smoky.
The dark wheat varieties are made with darker, more highly kilned malts both wheat and barley. The Weizenbocks typically have a much higher alcohol content than their lighter cousins.
Aventinus is an example of Weizen Doppelbockstronger and darker version of Weizenbock,   made by the G. It gets its name due to suspended yeast and wheat proteins which cause the beer to look hazy, or white, when cold. It is a descendant from medieval beers which were flavored and preserved with a blend of spices and other plants such as corianderorangeand bitter orange referred to as " gruit " instead of using hops.
Sweetened syrups of lemon, raspberry or woodruff herb are often added before drinking. Its ingredients include coriander and salt, which are unusual for German beers. Belgian Lambic is also made with wheat and barley, but differs from nearly all beers in the use of wild yeast for spontaneous fermentation. A variation on the barley wine style involves adding a large quantity of wheat to the mash bill, resulting in what is referred to as wheat wine. This style originated in the United States in the s.
Wheat beers vary in name according to the place in which they are brewed and small variations in the recipe.
Esters vs. Phenols in Beer
Among those used are:. In Belgium, witbier is usually served in a ml glass; each brewery Hoegaarden, Dentergems, etc. Kristallweizen especially in Austria and American styles of wheat beer are sometimes served with a slice of lemon or orange in the glass.
This is not traditional in Bavaria, and is generally frowned upon there.
In northern Bavaria, it is common to add a grain of rice to kristallweizen, which causes a gentle bubbling effect and results in a longer-lasting foam. When serving a bottled unfiltered wheat beer hold the glass on an angle and pour slowly.
Hop flavor and aroma are typically low. The ester and phenolic aspects are produced by the special type of yeast, rather than the high fraction of wheat in the grain bill. The carbonation level can range from 5. This produces a generous stand of foam, especially in light of the high protein content of wheat malt.
From Wikipedia, the free encyclopedia. Redirected from Wit beer. Defenestrative Pub Co. Brewing Insights Blog. Anchor Brewing Company. Retrieved 26 February The Independent.Phenolic flavors and aromas in beer are most often described as clovey, spicey, smokey, band-aid-like, or medicinal flavors and aromas.
Except in a few beer styles where some of these flavors are considered appropriate, these compounds are for the most part considered a flaw.
The most common source of the clove-like and spicey aromas in beer are the classic German hefeweizen-style yeasts. These yeasts convert ferrulic acid from malt into a compound which smells just like cloves, 4-vinyl guaiacol. The reason most hefeweizen and other German wheat based beers display so much clovey phenolics is because wheat contains more ferrulic acid than barley.
Many other yeasts produce detectable phenolic flavors as well. Many Belgian yeast strains and some British yeast strains will produce the same compound, although on a much smaller scale. One of the primary culprits of off flavors attributed to phenolic flavors and aromas are wild yeasts. These wild yeasts will produce many types of phenol compounds, but most of these are not the commonly accepted clove or spicy aromas and flavors, but a strong medicinal band-aid-like flavor which is not pleasant at all.
Before attributing the medicinal flavors to wild yeast, you should be aware of the effect that chlorine has on beer. When you brew with highly chlorinated water, the chlorine reacts with naturally occurring phenols in the beer to form chlorophenols.
This is a common flaw in home brewed beer and is easy to remedy by filtering with activated carbon or using either bottled water or Reverse Osmosis RO water. The yeast strains which produce the common clove-like phenolic flavors and aromas in beer do so as a part of their normal metabolism.
These yeast strains have enzymes which most of the other brewers' yeasts lack. If you are having problems with phenolic aromas and flavors in your beer, a change in yeast will probably solve the problem.4 Disgusting Off Flavors That Can Mess With Your Beer
Many of the homebrewer's problems stem from their mash and sparge routine. Phenols extracted from malts during the mash and sparge are called polyphenols, or tannins. These polyphenols react with proteins in the wort to form chill haze or permanent haze. Sometimes if hot-side aeration occurs, oxidized fusel alcohols flavors in beer are created. Another source of polyphenols in your wort is from malt and hop additions.
When hops are added in the boil, polyphenols are extracted and end up in the wort. High wort pH will increase this extraction but the polyphenols will not dissolve readily until the pH drops below 5.
Purchase your Hanna pH meter at MoreBeer. Tannins in the husks of malt are there to act as an astringent inhibitor against fungal and bacterial attack. The majority of the polyphenols in wort come from the malt.
If you are having astringency problems from polyphenol extraction in your malts, try stopping the sparge when the SG reaches 1. Sparge water acidification is not normally done by the homebrewer, but stopping your sparge early and controlling sparge water temp are easy fixes. One problem in trying to detect phenolic problems in your beer is that many people are insensitive to these aromas and flavors which many find objectionable.
These people are genetically incapable of detecting phenolic flavors or aromas. So, what do you do if you just can't detect the problems others find in your beer?
About the only thing you can do is have someone else taste your beer for you. Learn to rely on their senses. I'm sure they won't mind, after all, they will be getting a constant source of free beer. There are several other sources of phenolic flvors which make their way into your beer.
One is spoilage bacteria in your brewing water. Algae produce many phenolic compounds and are found in any water supply which is exposed to sunlight. Water sources exposed to industrial waste will be high in phenols.
Be wary of using water taken from a surface source.