Would you recommend tasting your home brew towards the end of fermentation to see where it’s at in the process to ensure quality? Do professional brewers taste along the way?
Zack Rowland
Boise, Idaho

Hmmmm, let me think about this for a nanosecond . . . yes and yes! I absolutely recommend tasting beer while “in process” and professional brewers certainly taste their beer as it moves through the brewery. I could write a book on tasting throughout the process but don’t have the space or time for such an endeavor. I will give you a few reasons for tasting while beer is transformed from wort to beer.
   
The first basic reason for tasting beer before bottling day is to spot problems that can be fixed. For example, if you taste your beer during aging and smell diacetyl or acetaldehyde you can easily respond to this by extending your aging process (assuming that you don’t want diacetyl or acetaldehyde in the finished beer).
   
In contrast, if you filter this hypothetical batch of beer and do so prematurely there is no remedy. Let’s say you’re brewing a batch of IPA and you have really beefed up the bitterness in the kettle and plan to balance the hop bitterness with a big hop punch from dry hopping. But you messed up and did not add enough hops during aging to get the aroma you desire. The brewer who tastes during the process easily spots the deficiency, adds more hops and ends up with a really nice beer. These are pretty obvious examples; brewing is not so complicated, and if you think of how to use your senses to monitor brewing you will discover all sorts of really good uses, including the application of the most useful of senses . . . common sense.   
   
Another check during process that I like to remind new brewers to keep an eye on is specific gravity. Too, too many homebrew recipes are written in such a way that implies that fermentation happens like clockwork. “Ferment for seven days and transfer to the secondary” — these types of directions really should not be followed literally. If you follow a recipe without doing any tasting along the way your chances of disappointment increase with every key point that is not checked.
   
Brewers also want to taste along the way to spot problems that cannot be solved. Whether you are a homebrewer or a professional brewer there is no sense in shepherding a batch of beer through the entire process if it isn’t good. You want to spot the certain loser as soon as possible and cut bait.
   
Another consequence of not spotting errant batches is the potential that the cause of the problem was more than bad luck. If you have a systematic problem, like bad yeast, or a problem with your cleaning regimen that recently popped up, you really want to identify the problem and get it solved before you end up with lots of bad beer. This attention to in-process detail is diligently practiced by the world’s best brewers — from Anheuser-Busch to Sierra Nevada.
   
One very real note of caution is not to contaminate your batch by using poor sampling methods. Another thing to be careful about is the temptation to over sample, especially for those batches that are really showing promise. You don’t want to wake up to bottle that great batch of IPA only to realize that your yield is a
case short!
   
In conclusion, yes, do taste your beer during fermentation and throughout the brewing cycle and use the data you collect to make decisions to move the beer through the process.

I recently started drinking mead that I brewed and have been aging for about a year. Some friends that I have let try it have mentioned that it smells like nail polish remover. As far as taste goes it tastes good and I would love to keep drinking it, however, I read an article in BYO that mentioned higher alcohols. I understand this process and it is quite possible this is the reason why my mead smells like nail polish remover. So my real question is can I safely keep drinking this mead or is it something I should pour down the drain? More directly, are fermented drinks that have higher alcohols safe to drink?
Matt Millward
Tucson, Arizona

Before you dump your mead down the drain, please read my answer! The aroma you describe is the distinctive scent of ethyl acetate. This nail-polish smelling compound is the most common acetate ester found in beer for one very simple reason; ethyl acetate is formed during fermentation when ethanol is enzymatically coupled with the acetate moiety of acetyl-CoA (a key intermediate in the EMP Pathway). In general, an ester results when an organic acid and an alcohol combine in a condensation reaction. In fermentation, ester production is catalyzed by enzymes.
   
Esters are normal to fermented beverages and are responsible for much of the aroma derived during fermentation. Many people do not like beer, wine, mead, sake, etc. that has very strong ester notes. Certainly nail-polish remover is not something I want to take note of when I want to enjoy one of my beers. Other esters include isoamyl acetate, ethyl hexanoate and ethyl heptanoate just to name a few. These compounds contribute fruity aromas such as banana, pear drop, apple and cherry to the nose of fermented beverages. Most people associate esters with fruitiness and not solvents.
   
Higher alcohols, also called fusel oils, are totally different than esters. The name “higher” alcohol comes from the fact that these compounds have a higher molecular weight than ethanol, which is the most common alcohol formed during alcoholic fermentation. While ethanol is the result of glucose fermentation by yeast, higher alcohols are primarily the by-products of amino acid metabolism. Higher alcohols are often described as spicy, vinous and alcoholic.
   
One reason people speak ill of higher alcohols is because when they are present in high levels they lead to headaches and hangovers. During the distillation process it is desirable to remove higher alcohols by controlling which cuts from the still are collected. White distillates, like vodka, should be very pure, and anything collected except ethanol and water is pretty much avoided, although pure ethanol and water mixtures are usually not what you find in most bottles of vodka. Brown spirits like whiskey get much of their aroma from higher alcohols, and producing a super clean distillate is not the goal of these types of distillation operations. Indeed the equipment used, such as pot stills, Armagnac stills and Cognac stills, are not designed to produce pure distillates. So even if your mead was chock full of higher alcohols it still would not be cause for sending it to the sewer.
   
Higher alcohols can react with organic acids and their metabolic cousins that are attached to coenzyme-A to form esters other than ethyl acetate. Long chain fatty acids (a type of organic acid) are involved in lipid metabolism. When yeast cells are growing they must synthesize fatty acids

Brew Your Own Technical Editor Ashton Lewis has been answering homebrew questions since 1995. Do you have a question for the Wizard? Send it to This email address is being protected from spambots. You need JavaScript enabled to view it. .