Finding the cause of a consistent off-flavor

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dttk0009

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Hi all,

Unfortunately, I've been dealing with a consistent off-flavor in pretty much all of my beers since I started brewing again just over a year ago. I've been trying to narrow down the possible causes for the off-flavor, but so far, I've had little luck in finding and eliminating it.

I started brewing when I stilled lived overseas in SEA about 5 years ago, and I distinctly remember that when I brewed there, my beer did not have this particular off-flavor.

Basically, the initial nose and flavor of the beer is fine. However, shortly after swallowing, this aftertaste that I can only describe as bready, almost like pumpernickle or dark bread, sets in. It becomes especially apparrent if you exhale through your nose. Additionally, mucus forms on the back of my throat, which feels almost phlegmy.

It's not that the particular aftertaste is bad, it's just strange and so far I haven't been able to find out what it could be. I thought for a long time that it could be diacetyl given the "slickness", but it doesn't really quite match, especially since I'm not getting imitation butter or butterscotch. Then I thought it could be tannins, but I'm not quite sure either.

Steps I have taken to eliminate off flavors:

  • Analyze water chemistry and add lactic acid to bring mash pH between 5.2-5.6.
  • Mill own grain to optimize crush size (might be crushing too small though)
  • Good temp control during fermentation chamber with Inkbird/chest freezer.
  • Give my fermentation some time in the upper ranges, even if it might not be conventionally needed.
  • Got some better equipment to control mash temperatures accurately.
  • Try really hard to avoid oxidation after fermentation has started. (Doesn't always happen though)
Anyway, friends and family have a hard time finding this off-flavor and tell me that the beer "tastes great anyway", but I know I'm not crazy since I can definitely notice it in my own beer and not in those brewed by, say, local microbreweries.

Sorry if the description of the off-flavor is a bit vague, but I hope it sounds like something familiar to someone out there.
 

jwalk4

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  • Try really hard to avoid oxidation after fermentation has started. (Doesn't always happen though)
Anyway, friends and family have a hard time finding this off-flavor and tell me that the beer "tastes great anyway", but I know I'm not crazy since I can definitely notice it in my own beer and not in those brewed by, say, local microbreweries.
I think I know the flavor you're talking about, and I have had experiences with old/moldy bread off flavors before.

First look to your recipes. Stale ingredients can be a source of weird malt flavors. I have also found that some recipes that use Vienna malt and/or Marris Otter can have an over whelming bready-ness, especially when hop and yeast flavors fade. Try Munich as a sub for Vienna, or plain ol' 2 row for Marris Otter. Both grain substitutions change your recipe significantly, but it might help you with the bread flavor.

You didn't say if you keg or bottle. Either way, ensure that your sanitation is on point and that no mold is present in your system. If you keg, replace your hoses and take apart your facet for scrubbing with pbw before reassembling and sanitizing. If you bottle, soak and scrub with pbw and store your bottles in a clean environment (not in a dank basement).

Additionally, I wonder if you are considering your oxygen uptake during your brewing process. Look into LODO brewing and try an incorporate one or two of those methods to reduce potential HSO. Some LODO methods are easy, like adding strike water to grain, and shortening mash times. Other LODO processes will lengthen your brewday, like preboiling and chilling your strike water, and avoiding agitation during chilling.

Weirdly, my bready problems disappeared when I moved from my last home, but I am still skeptical of Vienna malts in large amounts.

Cheers,
 
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dttk0009

dttk0009

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I think I know the flavor you're talking about, and I have had experiences with old/moldy bread off flavors before.

First look to your recipes. Stale ingredients can be a source of weird malt flavors. I have also found that some recipes that use Vienna malt and/or Marris Otter can have an over whelming bready-ness, especially when hop and yeast flavors fade. Try Munich as a sub for Vienna, or plain ol' 2 row for Marris Otter. Both grain substitutions change your recipe significantly, but it might help you with the bread flavor.

You didn't say if you keg or bottle. Either way, ensure that your sanitation is on point and that no mold is present in your system. If you keg, replace your hoses and take apart your facet for scrubbing with pbw before reassembling and sanitizing. If you bottle, soak and scrub with pbw and store your bottles in a clean environment (not in a dank basement).

Additionally, I wonder if you are considering your oxygen uptake during your brewing process. Look into LODO brewing and try an incorporate one or two of those methods to reduce potential HSO. Some LODO methods are easy, like adding strike water to grain, and shortening mash times. Other LODO processes will lengthen your brewday, like preboiling and chilling your strike water, and avoiding agitation during chilling.

Weirdly, my bready problems disappeared when I moved from my last home, but I am still skeptical of Vienna malts in large amounts.

Cheers,
Yeah, I keg, and I'm pretty meticulous about sanitation too. Could be oxidization. Sometimes a bit does splash or gets infused through the siphon. Would that be enough to create that much of a strong off-flavor?

The only thing I haven't eliminated yet is my plastic fermentation bucket. Maybe it is just an infection.
 

budonze

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Have you opened and cleaned the inside of your kettle ball valve? A few years ago I was getting a weird off flavor and the gunked up residue in the ball valve was the cause.
 

MrPowers

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Have you used one consistent yeast strain since you started brewing? I would always get a very bready off flavor when I used US-05? It's sometimes there with other dry yeasts too.
 

bradleypariah

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I siphon into a corny keg, clear headspace with CO2 and let it age/carb over the coming weeks.
Do you add CO2 to the corny keg prior to siphoning your beer into it? CO2 is heavier than oxygen. If you spray your CO2 line into the keg for a few seconds, then let it settle, you'll have a pool of CO2 to rack onto.

Even if the beer splashes from the siphon, it can't get oxidized.

How long are you letting your beers age? You're not tasting diacetyl, right?
 

mattdee1

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It's really hard to say based on nothing but a subjective description of the "problem" but honestly, if your ingredients are of reasonable quality, your mash pH is in check, and the off flavor is nonetheless related to malt aspects of the flavor profile, then my bet is that you simply need to brew a better recipe. This has certainly happened to me multiple times, especially in cases where I just make up and brew an untested recipe.

If I were you, I'd go right back to basics and brew something simple (e.g., low-IBU blonde ale with neutral yeast) and/or a tried and true recipe from the archives on this site.
 

yowzers

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Sounds like my problem. I was oxidizing my product with an autosiphon and did not realize it for ages. It does not take much to ruin a batch. Check your siphon for leaks. You can test it using water. Siphon directly into a clear container with the discharge hose submerged. You should see no bubbles. When you siphon into your keg the hose should go all the way to the bottom by the way. You can also do a closed transfer, but that won't help if your siphon is sucking air.
 
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dttk0009

dttk0009

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Do you add CO2 to the corny keg prior to siphoning your beer into it? CO2 is heavier than oxygen. If you spray your CO2 line into the keg for a few seconds, then let it settle, you'll have a pool of CO2 to rack onto.

Even if the beer splashes from the siphon, it can't get oxidized.

How long are you letting your beers age? You're not tasting diacetyl, right?
Honestly, I think I'm not, but then again, I have no frame of reference other than what I've read. I recently joined the city's homebrewer's club and will bring some of my beer to the meet up for some input.

Also, I do not fill my kegs up with CO2, that's a pretty neat idea, will definitely do that with the IPA currently fermenting.

Thanks also for all the other suggestions. I'll go through them one at a time to see if it eliminates the off-flavor in the coming batches.
 
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dttk0009

dttk0009

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Just to update this, I've taken extra steps in my last 2 batches, and it really did seem to be oxygen, because the off-flavor was no longer preset. It just never occurred to me that that flavor would be described as "cardboard", just had this weird, bready, nosey flavor.

Both the Wit and the IPA don't have it, where I was very careful when transferring to keg, after which I immediately purged with CO2.

The previous batch, which did have strong off-flavor, I filled up the keg a bit sloppily, then lugged it over to the keezer, sloshing it around before purging. Pretty dumb, but probably a good way to get oxygen related off-flavors.
 

MrHopScotch

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Glad to hear you're having some success! For beers that are particularly susceptible to oxidation (big IPAs etc.), I go one step further:

I fill the corny keg with starsan and seal up the keg. This displaces nearly all the air/oxygen inside. Then I use co2 to push the sanitizer out of the keg through the liquid line. After this step, the inside of the keg is almost completely co2 (and the liquid dip tube, post, etc. are nicely sanitized). I crack the lid open, do a nice quiet transfer with little to no splashing, and purge the headspace 4-5x at 30 psi.

If I had a conical, I would probably do a closed transfer, but this has been working very well for me with my current setup.
 

IslandLizard

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Glad to hear you're having some success! For beers that are particularly susceptible to oxidation (big IPAs etc.), I go one step further:

I fill the corny keg with starsan and seal up the keg. This displaces nearly all the air/oxygen inside. Then I use co2 to push the sanitizer out of the keg through the liquid line. After this step, the inside of the keg is almost completely co2 (and the liquid dip tube, post, etc. are nicely sanitized). I crack the lid open, do a nice quiet transfer with little to no splashing, and purge the headspace 4-5x at 30 psi.

If I had a conical, I would probably do a closed transfer, but this has been working very well for me with my current setup.
You really want to eliminate O2, don't open the keg after the 100% Starsan pre-purge, leave the lid on. Fill through the out post, opening the PRV (or stick an open QD on the gas-in post to vent).

There are lots of posts on O2 free transfers, or in practice, limited O2 transfers.
 

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