I've been making homebrew for 8 years now. Recently, (over the last 8 months or so) I've noticed that in almost all of my beers, there is a distinct clove-like aftertaste. I assume that there is an off-flavor coming from somewhere, but I'm not quite sure how to track down where it's coming from. It's an uphill battle, too, because I'm especially sensitive to this aftertaste and don't like it. Others to whom I give my beers don't seem to mind it, but I guess I don't brew beer as much for others as for myself to drink, and it's gotten to the point where it's almost undrinkable for me.

I recently upgraded my system to a Sabco BrewMagic system, and, for the most part, the results have been pretty good. For better or worse, I also purchased a Chill Wizard: https://brewmagic.com/products/chill-wizard-system/ I say "for better or worse" because the thing keeps getting clogged up and in general, it's a pain to use.

I'm absolutely uncompromising when it comes to sanitation, so it doesn't seem like it's a sanitation problem. However, the chilling step post-boil could be introducing something, since I don't know what's happening inside the chill wizard. I typically fill a 15gallon fermenter up with sanitizer and run it through the chill wizard for about 5 minutes as the last step before transferring the wort using the chill wizard to the now sanitized fermenter.

I don't use Belgian yeast, so I doubt that the specific strain of yeast is causing the problem. I usually use Wyeast 1098 - British Ale - for most of my ales, and they ferment at around 66-68F, which I closely monitor using a Tilt hydrometer.

One thing that could be problematic is that I'm not super reliable about transferring out of primary to secondary immediately as soon as I've reached gravity. (In some cases, I actually wait way too long, but this isn't generally the case). I typically transfer from primary -> secondary after about 7 days, but, roughly speaking, almost all of my beers are at their final gravity within 4 days.

I carbonate in a keg using a carbonation/diffusion stone, usually over a period of 2 days. Before carbonating, I boil the lid and carbonation stone/assembly for roughly 5 minutes in order to sanitize it.

I doubt that anyone is going to be able to tell me exactly what's wrong, but I'm looking for a strategy for how I might go about troubleshooting the cause of this.

5 Answers 5


Clove-ey flavor in my experience is due to

  1. Yeast health (namely- hot fermentations)
  2. Chloramines in water
  3. Bacteria infection

My prime bet is fermentation temps- you say you ferment at 66-68F - is this ambient temp- or temp controlled? Are you pitching your yeast when your wort is hot? I would discount an infection (#3) if the clove doesn't develop to something way worse in a month (burning, bandaid, chemically flavor).

Have you gotten a different result with different strains? Call me crazy- but I think wyeasts are a little more prone to hot-side phenols, at least in some strains (i.e. 1056 vs WLP001) and the clove-ey flavor is typical when english strains move towards the upper 70s range.

Water could be a culprit, although I think if your water is so chlorinated it does this in beer- you would smell it coming off the tap.

  • 1
    Wow, great information. Thank you. I am actually tracking the temp with a Tilt, so, we TARGET 66-68F, and those are the average temps. However, these latest beers were fermented in summer, and, even though I was fermenting in a basement closet, the temp is variable. It could get as high as 76F ambient, so I don't discount the possibility of thermal phenols.
    – jwir3
    Nov 10, 2020 at 17:49
  • I didn't know that about Wyeast. I have tried a few others - WLP001 is another of my favorites - but they seem to have the same results. I will say it's not detectably moving toward a much worse flavor in a month or so, but it does intensify (although this could be my imagination). Also, I boil the water prior to cooling it to temp for the mash to eliminate chlorine in the water... I doubt chlorine is the problem, but it could be something else in the water, since it is just tap water.
    – jwir3
    Nov 10, 2020 at 17:51
  • The wyeast observation is just my own- I'm not discounting that it's high quality brewers yeast. A beer that is fermenting generates quite some heat of its own- 76 ambient during a vigorous fermentation could easily be pushing into 80F. This would certainly kick out some phenolic flavors.
    – rob
    Nov 11, 2020 at 14:28

It sounds like you have a sanitation problem. Clove flavors (derived from a compound known as 4 vinyl guaiacol, 4VG for short) are produced by POV positive beer yeasts (e.g. Belgian Abbey and German Weizen yeasts), by some wine yeasts, and by most wild yeasts. The latter are most likely your problem.

However, not all such flavors are really clove flavors. If what you taste is somewhat reminiscent of improperly pickled olives, the aroma inside an old oak cabinet or old leather, the most likely culprit is not 4VG but tannin. The latter is extracted from the grain husks if the pH of your mash is too high, either as a result of brewing water quality / mineral composition, or as a result of too much water and too little grain.

If you suddenly noticed a persistent change in the quality of your beer, my guess is that you either have a sanitation problem (persistent wild yeasts) which you need to combat with fire and sword (think serious chemical or heat application) or the quality of your water has changed.

My suggestion would be toclean the heck out of everything (and I mean everything); test your mash pH (which should be somewhere in the 5.1 to 5.4 range) and bottle/keg as cleanly as possible; then report back on the taste of your next pint!


Do you know when the clove flavor gets into the beer? I'd try the wort pre boil, post boil, and then the beer right after fermentation.

That said, a quick web search suggests this off-flavor as phenolic. Clove is on the harmless end of this off-flavor; I had beer that tasted medicinal and like plastic. This can depend on what the water supplier puts in the water, so some batches may come out ok, and others may have a strong off-flavor, depending on the water quality and what was added.

I never had that problem again after using reverse osmosis filtered water (25c gallon, just have to remember to buy water before brew day).

  • It's possible that it's coming from the water. I almost exclusively use tap water. The thing is, since I've had this problem, I've actually boiled the water prior to putting it in the mash (to try to eliminate Chlorine getting into the wort). This doesn't seem to help, though, so I wonder if it's worth trying RO water. Not a bad suggestion, thanks.
    – jwir3
    Nov 9, 2020 at 16:35

To eliminate chloramine (as distinct from chlorine), your water apparently needs to be boiled for a minimum of 20 minutes. Alternatively, you can use the chemical method - Campden tablet(s) - sodium metabisulphite. This latter method works for me, but just make sure you don't overdose - one tablet per 10 gallons is a guideline.

  • I think you have that a bit backwards. Heating will remove chlorine as it evaporates easily. Choramine needs to be chemically broken down, or carbon-filtered out. Campden tables are a commonly suggested method.
    – Kingsley
    Dec 2, 2020 at 2:26

I'm wondering if you have a yeast infection of a POF+ yeast from a previous batch (or something wild).

If you rely solely on acid-based sanitisers for sanitation (like StarSan, etc.), these do not kill yeasts effectively (that's why they're "no rinse"). It's a good practice to occasionally vary your sanitisation procedure - use heat, or perhaps Iodophor(sp?) to kill a wider range of micro-organisms, including wild yeasts.

When I use a chiller, I simply recirculate boiling wort through it for a few minutes to sanitise it. That way it only needs to be clean, and you're not applying an acid-rinse to copper plates.

And for-what-its-worth, my palette is super-responsive to clove flavours too, so you have my sympathy. I'm still working on pushing my wheat beers away from clove esters, and into the banana / bubblegum zone.

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