How to Do Your Own Off Flavor Beer Tasting

It seems the real key to becoming a good homebrewer is practice and the ability to improve your process batch after batch. A big piece of that is being able to honestly evaluate and diagnose defects in your own beers.

I’d heard about off flavor beer tasting kits and courses that you can take to better identify the flaws in beers, but the cost had always been prohibitive. Yet it was such a cool idea, and a worthy educational event, that my homebrew club decided we had to find a way to do one ourselves.  In the end, the actual act of creating these flawed samples was as simple as adding a few drops of butter extract or lactic acid to some macro beer. The real learnings came from the additional research that needs to be done to explain what causes these off flavors and what we can do, as brewers, to avoid them.

How to Do Your Own Off Flavor Beer Tasting

Making these flawed beers was relatively easy. You start with an American Light Lager that has almost no flavor (I was redundant just then. Did you catch it?) and make sure you have at least 1 oz of beer for each person AND off flavor you are replicating. So, if you were trying 6 off flavors and you have 6 people at the tasting, you would need at least 36 ounces of beer. I’ve heard that Coors Light is often used for these tastings, but we used Bud Light.

What You’ll Need

A Pitcher (with measurement lines)

Macro Light Lager Beer

Small Tasting Cups (3oz ramekin-style plastic cups will work)

A Dump Bucket

The Additives

Teaspoons and a Dropper (for measuring)

A Big Spoon (to stir together the beer and additives)


You’ll need a measuring container of some sort to determine the right amount of ounces for that bad flavor flight, and then you need to put in the additive. This is where you probably want a couple of tasting bartenders with pretty good palates.  You’ll need to mix in just enough of the additive to make the right aromas and flavors apparent to the tasters, but not so much that it overwhelms. (The additives that we used are at the bottom of this post.) Once you have the right mix, you can pour little 1 oz samples for all the attendees and then give them some time to smell and taste the beer.

How to Run the Tasting

We ended up doing our tasting blind, save for the bartenders of bad beer, and I think that enhanced the experience. It gave the tasters a chance to savor (perhaps that is the wrong word) and work through the off flavor before being given any expectations. After everyone had a chance to think about the beer, we had the tasters raise their hands to offer up what flavors and aromas they were tasting. I think saying these things out loud helped, as we all taste things in our own way and with our own abilities. It is important to understand how you perceive the taste and aroma.

And don’t feel like you have to try every off flavor in one tasting. We ended up breaking ours into two sessions. We might need that time to let our tongues recover.

The Key Learnings

For us, getting in touch with these off flavors was very important, but just as important was discussing what makes these off flavors happen and how we could, as brewers, avoid them in the future. That is the practical insight, and there are a few sites out there that do a good job of explaining the why and how to prevent them. (John Palmer’s Guide will do.) Identifying the rotten egg smell of sulfur is great, but knowing that it is a natural by-product of some yeast strains that will dissipate over time, or that could be a result of poor sanitation, or perhaps it can come from racking to a secondary, and taking it off the yeast, too soon is invaluable.

From this exercise, the most reoccurring preventative measures a brewer can make to improve their beers were:


Temperature Control


Letting Your Beer Sit on the Yeast Long Enough to Clean Itself Up

The key is to have fun, and laugh, and wince, and have a big bucket to pour the leftover samples into. And be honest. Tell a story about the beer that you made that tasted just like THIS one. I don’t trust brewers who claim they haven’t made a batch that smelled like movie theater popcorn or wet cardboard. Those are great stories and great inspiration to keep your process tight and not do make that mistake again.

As a side note, if you see a course being taught about off flavors, I’d still try to attend it. What we did here was lo-fi and very educational, but it wasn’t perfectly scientific and I’m sure the pros could pull this off more elegantly.  But this is an easy and quick way to up your game and it is a very cool thing to do with friends.

The Additives We Used for Off Flavors:

Acetobacter – Vinegar

Astringency – Grape Tannins

Cidery – Apple Cider

Diacetyl – Butter Extract

Esters – Banana Extract

Fusel Alcohol – Ethyl Acetate

Phenols – Chloraseptic Throat Spray

Sour – Lactic Acid

Off Flavors We Will Do Another Time and Possible Additives:

Acetaldehyde – Green Apple Flavoring

DMS – Cooked Corn

Oxidation – Sherry

Skunky – We will probably just leave a few light beers out in the sun in their clear bottles

Sulfur – Some sort of Sulfur


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