Off flavor in dark beers

[AWilliams]

So, I brew IPAs for my wife and darker beers for myself. My IPAs turn out pretty well and we're both very pleased with those, no off flavors that I can detect. However, my porters and stouts always have a sourish off taste to some extent that I don't perceive in my lighter colored beers.

I believe my brewing process is solid. I use Brew'n'water for my water profile. I dechlorinate with campden tablets. I generally hit my mash temps. I aerate my wort well and pitch the amount of yeast that Beer Smith calls for. I also have a fermentation chamber to control temps. No amount of time in the fermenter or kegged reduces this flavor. I also had this issue when brewing extract kits.

I'd appreciate any suggestions.

 

[madscientist451]

My first thought would be to try buying jugs of spring water and brew the same recipe as your last porter/stout so you can compare.
Or you can start with distilled and build a water profile.
Reading between the lines, you are using additives to hit a water profile?
Any chance the combination of chlorine in your water, existing dissolved minerals, campden tablets, and water additives is producing the sour taste?
I'm also thinking the the same taste is in your IPA's but is being covered up by the hops, or you are using different additives for a different water profile?
Perhaps just make batch with purchased spring water, don't add anything to it and see if the sour flavor is still there.
My second thought is that you've got an infection going somewhere, and if you use spring water and still have the problem, that's the next direction I'd investigate.

 

[TheMadKing]

So, I brew IPAs for my wife and darker beers for myself. My IPAs turn out pretty well and we're both very pleased with those, no off flavors that I can detect. However, my porters and stouts always have a sourish off taste to some extent that I don't perceive in my lighter colored beers.

I believe my brewing process is solid. I use Brew'n'water for my water profile. I dechlorinate with campden tablets. I generally hit my mash temps. I aerate my wort well and pitch the amount of yeast that Beer Smith calls for. I also have a fermentation chamber to control temps. No amount of time in the fermenter or kegged reduces this flavor. I also had this issue when brewing extract kits.

I'd appreciate any suggestions.

Can you post one of your recipes and the water profile you used?

My initial suspicion is that you over-acidify your mash with darker grains. That's really the only thing common to all roasted grains that can cause a sour note that I can think of.

 

[brew_darrymore]

I had the same problem. My first stouts were turning sourish. You're using Brunwater, so you probably know that dark roasted malts have higher acid content. Using a lot of dark malts in your recipe could be one reason for that residual sourness that you describe. I made that mistake. I am also using Brunwater, but I found out that the predicted pH was way higher than the actual mash pH, for example predicted pH 5.40, measured pH 5.10.

Do you have a pH meter to measure your mash pH? Perhaps your water has less alkalinity than you think. For my stouts, I have to add 2-3 grams of baking soda to brng the pH up to 5.4-5.5.

 

[TheMadKing]

I had the same problem. My first stouts were turning sourish. You're using Brunwater, so you probably know that dark roasted malts have higher acid content. Using a lot of dark malts in your recipe could be one reason for that residual sourness that you describe. I made that mistake. I am also using Brunwater, but I found out that the predicted pH was way higher than the actual mash pH, for example predicted pH 5.40, measured pH 5.10.

Do you have a pH meter to measure your mash pH? Perhaps your water has less alkalinity than you think. For my stouts, I have to add 2-3 grams of baking soda to brng the pH up to 5.4-5.5.

If your predictions are that far off, I suspect that you've input something wrong into Bru'nwater. It has always consistently been within .02 of my measured pH no matter the recipe.

 

[brew_darrymore]

If your predictions are that far off, I suspect that you've input something wrong into Bru'nwater. It has always consistently been within .02 of my measured pH no matter the recipe.

You're absolutely right. I think it's my city water report which I'm planning to verify by getting a Ward Lab report soon.

It's funny that Brunwater is consistently predicting 0.2 points higher, so I just shoot higher and end up measuring more or less where I wanted to be. I think my tap water may be less alkaline than the city water report claims.

 

[TheMadKing]

You're absolutely right. I think it's my city water report which I'm planning to verify by getting a Ward Lab report soon.

It's funny that Brunwater is consistently predicting 0.2 points higher, so I just shoot higher and end up measuring more or less where I wanted to be. I think my tap water may be less alkaline than the city water report claims.

If it's consistently off by the same amount, then I bet you're right. Water supplies are also variable too, so you might take a water sample at different times of the year and see if there's any seasonal variation.

 

[Sillybilly]

I just made a porter that had the same problem, I had a pH meter fuzz out on me while adjusting water/mash and long story short I added way more latic acid/gypsum than I needed. Noticeable acid/tartness in taste but not too unpleasant. Any idea if the acidity will mellow out with time? I feel like between one bottled 3 weeks vs 4 weeks it is slightly less, but could just be a different perception when tasting.

 

[brewcat]

What grains are you using?

 

[AWilliams]

Sorry for taking so long to get back to this, life got a little hectic, also thanks for the suggestions so far. My last recipe was this:

12lbs 2 row
8oz caramel 120
12oz chocolate
10oz black malt

All of my dark beers have had this issue to some extent including a couple extract kits I made. I had a Ward Labs water report done and use Bru'n'water based off of it. I do not have a PH meter.

I have the above batch still in the fermenter, it's been in about 8 weeks a I was hoping the sourness would fade. It has not. The beer has a sourish smell to it, maybe even apple-like. I also have some gunk floating in the top, is this left over yeast or something else?

 

[TheMadKing]

Sorry for taking so long to get back to this, life got a little hectic, also thanks for the suggestions so far. My last recipe was this:

12lbs 2 row
8oz caramel 120
12oz chocolate
10oz black malt

All of my dark beers have had this issue to some extent including a couple extract kits I made. I had a Ward Labs water report done and use Bru'n'water based off of it. I do not have a PH meter.

I have the above batch still in the fermenter, it's been in about 8 weeks a I was hoping the sourness would fade. It has not. The beer has a sourish smell to it, maybe even apple-like. I also have some gunk floating in the top, is this left over yeast or something else?

8 weeks is almost insanely long in primary.. You likely are having yeast issues. What is your normal fermentation schedule?

 

[SanPancho]

one thing i might point out- when you enter your grains into brunwater, you are supposed to categorize them- base, crystal, roast, acid. (off the top of my head)

not sure if that could give you so much error you'd get a sour flavor, but might be worth checking.

 

[chickypad]

Do you have a better pic of that fermenter? Where the light's hitting looks kinda pellicle-like to me (large white bubbles, broken ice pack appearance). Seems like an awful lot of head space to be letting that sit around for 8 wks.

 

[day_trippr]

^agreed^
There's definitely something growing in sheets on the surface...

 

[RM-MN]

8 weeks is almost insanely long in primary.. You likely are having yeast issues. What is your normal fermentation schedule?

Nope, nope, nope. I talked with a guy who left beer in the fermenter for 6 months and he said that wasn't too long yet. Personally I've left a beer for 9 weeks and it did nothing but improve.

 

[RM-MN]

I find that dark beers take some time to mature in the bottles so if you are drinking them too soon you might perceive an off flavor. 3 to 6 months in the bottle my stouts start getting much better and continue to improve for at least a year.

I see some trub floating on the surface of the beer in your fermenter. I do not see infection.

 

[AWilliams]

8 weeks is almost insanely long in primary.. You likely are having yeast issues. What is your normal fermentation schedule?

This was not my normal schedule. I was simply seeing if the off taste lessened or went away with more time on the yeast. I'm normally 3-4 weeks from wort to keg on dark beers.

 

[AWilliams]

Do you have a better pic of that fermenter? Where the light's hitting looks kinda pellicle-like to me (large white bubbles, broken ice pack appearance). Seems like an awful lot of head space to be letting that sit around for 8 wks.

I will get a better picture tomorrow.

 

[RM-MN]

This was not my normal schedule. I was simply seeing if the off taste lessened or went away with more time on the yeast. I'm normally 3-4 weeks from wort to keg on dark beers.

Pressurize your keg and let it set warm for a couple weeks. I bet you'll notice a difference. Longer than that will improve it more yet.

 

[TheMadKing]

Nope, nope, nope. I talked with a guy who left beer in the fermenter for 6 months and he said that wasn't too long yet. Personally I've left a beer for 9 weeks and it did nothing but improve.

I've left a beer for 10 days in primary and finished conditioning in a keg and it's been great.

I've left a beer in primary for 5 weeks and had intense autolysis flavors from dead yeast in the cake.

I've left a beer in primary for 5 weeks and it was my best pale ale ever.

This is the problem with anecdotal evidence, there's always other factors in play, so it proves nothing.

This has been a subject of much debate on this forum and in the homebrewing community at large and we aren't likely to achieve "the truth" here. Chances are, it depends on the beer, the yeast health, the temperature, and a hundred other factors. What works for 1 brewer might not work for another. In general, however, I would argue that it is better practice to get your beer off the yeast cake at 3-4 weeks to ensure you don't experience off flavors from yeast autolysis. Jamil Zainasheff, arguably one of the worlds leading experts on brewing yeast, argues for 3-4 weeks.

Actual fermentation of an ale is typically done in 6-8 days. The rest of the time is the reduction of diacetyl and acetaldehyde, so the idea is to balance the cleanup time with the risk of autolysis and 3-4 weeks seems to be the agreed upon "sweet spot" by a number of experts.

I'm not saying it's the "truth" but there is more evidence for that time frame than most others.

 

[chickypad]

I wasn't so much worried about the total time, I've done that before as well. It's more that it's a bucket (notoriously poor seals) with lots of headspace that you've been opening to sample. I'm usually thinking about oxidation risk, but from what many say it makes you more prone to infection too.

 

[AWilliams]

I wasn't so much worried about the total time, I've done that before as well. It's more that it's a bucket (notoriously poor seals) with lots of headspace that you've been opening to sample. I'm usually thinking about oxidation risk, but from what many say it makes you more prone to infection too.

It's a big mouth bubbler. That was the first time I had opened it.