BIAB Off Flavor

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Brewnolo

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I'm a new homebrewer and I made 4 batches by a BIAB method, English Pale Ale, APA, Blonde Ale (not belgian), and a Session IPA.

All the batches presented a strong taste (or aftertaste) and a smell that is difficult to match to a typical off flavor but I think that tends to be a yeasty off flavor or like a detergent off flavor.

Initially, I thought that could be a temperature trouble during fermentation, but the last 2 batches were fermented in a fridge with temp controller (at 18 +/- 1°C) and the off flavor continues so I discard this issue.

I clean with a neutral detergent and always rinse the stuff after cleaning so I don't think that the detergent causes that flavor. Also I considered that could be a trouble from my sanitizing product (Povidone-iodine diluted in water, 12.5 ppm) so in the last batch (now on primary fermenter) I used just alcohol 70% as sanitizer. In this last batch of 5 gallons (Session IPA, American Bitter - 21st Amendment clone) I taste the wort in every stage after mashing, after cooling, and after pitching and I didn't feel that off-flavor(could be a very subtle flavor after pitching but the hoppy flavors were very strong in that moment and could hide the off flavor).
So after 4 days of fermenting at 19 °C I take the hidrometer wort sample (1.015 SG) and I tasted it and this same flavour and aroma appeared, I tried again yesterday (day 7 of primary) and the flavor was stronger. I used 1 packet of dry yeast Safale US05 rehydrated. I think the flavor is from fermentation, all my batches were fermented just in a plastic Bucket (without racking to a secondary) for 9 to 11 days and I did cold crashing for 2 days before bottling.

I am quite meticulous with all the steps and procedure but I can't find yet the source of the problem. I'll appreciate if someone can help me with this problem.
 
My guess woukld be water chemistry since you are using a neutral yeast. If you aree fermenting at 18 degrees with 05 there should not be fermentation flavour issues. If you aren't adding any acid to the mash you can guarantee that your pH is too high with BIAB full volume. Ideally you want around 5.4-5.6 and my guess would be youre in the region of 5.8 to 5.9. That was my experience with full volume BIAB with my softish water anyway.
 
You do not need to sanitize you brew bag. Just a rinse in clean water and hang it to dry before storing. Your mash water will sanitize and the boiling of the wort will sanitize anything the mash temp didn't kill.

Have you tried Starsan as a sanitizer?
 
My guess woukld be water chemistry since you are using a neutral yeast. If you aree fermenting at 18 degrees with 05 there should not be fermentation flavour issues. If you aren't adding any acid to the mash you can guarantee that your pH is too high with BIAB full volume. Ideally you want around 5.4-5.6 and my guess would be youre in the region of 5.8 to 5.9. That was my experience with full volume BIAB with my softish water anyway.

In the last batch I used just bottled water trying to minimize problems. I really don't get an pH-meter yet, but that could be a possible cause. Thanks
 
You do not need to sanitize you brew bag. Just a rinse in clean water and hang it to dry before storing. Your mash water will sanitize and the boiling of the wort will sanitize anything the mash temp didn't kill.

Have you tried Starsan as a sanitizer?

I don't sanitize the brew bag I just wash it like you said. I only sanitize after boiling.
For the next batch I will buy Star San to try. Thanks
 
I have a couple of ideas/suggestions. I have read that the breakdown of fatty acids in trub can cause soapy flavors in wort. You said detergent like so I was thinking soapy might be analogous. However, this doesn't seem to apply to you as you've written you are tasting the off-flavor after only a few days. How much trub are you transferring into your fermenter?

You might consider adding a Campden tablet to your water to neutralize chlorine and possible adverse affects from it.
 
I have a couple of ideas/suggestions. I have read that the breakdown of fatty acids in trub can cause soapy flavors in wort. You said detergent like so I was thinking soapy might be analogous. However, this doesn't seem to apply to you as you've written you are tasting the off-flavor after only a few days. How much trub are you transferring into your fermenter?

You might consider adding a Campden tablet to your water to neutralize chlorine and possible adverse affects from it.

This is what I was thinking as well - oxidation of fatty acids.

I got a bit lazier when I switched from my 3v setup to eBIAB and was a) collecting cloudy wort pre-boil and b) transferring a fair bit of trub to the fermenter post-boil/chill. I definitely had some off-flavours from it that I never had previously with my 3v setup. On my last few brews when the mash was complete (I recirc continuously) I lautered clear wort into a bucket pre-boil before pulling the grain/bag and dumping the little bit of cloudy wort left over. Also went back to my original post-boil process of chilling and letting trub settle for 30 mins prior to running off clear wort into the fermenter. The off-flavour is gone.

I know a lot of people insist that clear wort isn't necessary, but that hasn't been my experience...

Campden is also a good suggestion. Either way, if you're using chlorinated water, you need to be doing something about that. Either activated charcoal or campden/k-meta. Typically chlorophenol presents itself as a Band-Aid flavour though.
 
I do BIAB no sparge and no filtering of break material too. I changed so many variables from crush, to water chemistry and pH, even slightly higher yeast counts, yet some of my beers still come out with a slight off-flavor like described in this thread. For my next brew I plan on filtering out a good portion of the cold and hot break post boil
 
I have a couple of ideas/suggestions. I have read that the breakdown of fatty acids in trub can cause soapy flavors in wort. You said detergent like so I was thinking soapy might be analogous. However, this doesn't seem to apply to you as you've written you are tasting the off-flavor after only a few days. How much trub are you transferring into your fermenter?

You might consider adding a Campden tablet to your water to neutralize chlorine and possible adverse affects from it.

I used bottled water for mashing and sparge so in theory this water shouldn't have chlorine but next time I could try adding a campden to discard this issue.

Another detail, I remember that just for the rehydrating dry yeast I used preboiled and filtered tap water. I don't know if this can cause that kind of flavor because finally this rehydrated yeast is diluted in wort (greater volume).
 
This is what I was thinking as well - oxidation of fatty acids.

I got a bit lazier when I switched from my 3v setup to eBIAB and was a) collecting cloudy wort pre-boil and b) transferring a fair bit of trub to the fermenter post-boil/chill. I definitely had some off-flavours from it that I never had previously with my 3v setup. On my last few brews when the mash was complete (I recirc continuously) I lautered clear wort into a bucket pre-boil before pulling the grain/bag and dumping the little bit of cloudy wort left over. Also went back to my original post-boil process of chilling and letting trub settle for 30 mins prior to running off clear wort into the fermenter. The off-flavour is gone.

I know a lot of people insist that clear wort isn't necessary, but that hasn't been my experience...

Campden is also a good suggestion. Either way, if you're using chlorinated water, you need to be doing something about that. Either activated charcoal or campden/k-meta. Typically chlorophenol presents itself as a Band-Aid flavour though.

After mashing my wort was a little bit cloudy but I read that boiling cloudy (grainy) wort can create husky/grainy off flavor(astringent) that in my case I didn't feel in the sample that I taste after boiling stage. I was careful to not transfer trub to my fermenter. Did you have this off flavor after boiling or during fermentation??
 
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After mashing my wort was a little bit cloudy but I read that boiling cloudy (grainy) wort can create husky/grainy off flavor(astringent) that in my case I didn't feel in the sample that I taste after boiling stage. I was careful to not transfer trub to my fermenter. Did you have this off flavor after boiling or during fermentation??

After fermentation.

If you left the trub out of the fermenter then less likely it's fatty acid oxidation. You mentioned you use a neutral detergent to clean your equipment... what do you use?

Also on all your batches, I assume the off-flavour persists once the beer is conditioned and clear? (i.e. you're not just tasting yeast in suspension?).

What water source are you using?
 
After fermentation.

If you left the trub out of the fermenter then less likely it's fatty acid oxidation. You mentioned you use a neutral detergent to clean your equipment... what do you use?

Also on all your batches, I assume the off-flavour persists once the beer is conditioned and clear? (i.e. you're not just tasting yeast in suspension?).

What water source are you using?

I use just a dishwashing detergent. I am from Paraguay (South America), so here I don't have availability of PBW, Star San or another similar product. But I am ordering from USA to try it in future batches.

Yes the off flavor persists in the bottled beer after conditioning.

I am using bottled water (mineral).
 
I'd leave the dishwash detergent alone when it comes to brewing equipment cleaning.

I'm sure you can buy washing soda, Na2CO3. It's very alkaline and will clean most brewery equipment. It's easy to wash off and leaves no residue. PBW contains 30% Sodium Metasilicate, a TSP substitute, and 70% Sodium Percarbonate. Those are very good cleaners too. Percarbonate releases Oxygen, leaving washing soda behind.

Sanitation with Iodine products is good, not necessarily inferior to Starsan. Many (US) brewers use Iodophor or similar products. You need to make sure your iodine sanitizer is rinse free, not all are. If not, you'll need to rinse it off after allowing it to do its work. Iodine can be tasted in very small quantities. Your sanitizer being "Povidone-iodine," where is that being used? In breweries? Is it rinse free. maybe the residue is what you're tasting.

Bottled mineral water? Do you know the mineral composition? If the water contains a lot of bicarbonates (HCO3-), it can screw up your mash pH unless you add enough acid to compensate. Other minerals can also let their presence known.
 
I'd leave the dishwash detergent alone when it comes to brewing equipment cleaning.

I'm sure you can buy washing soda, Na2CO3. It's very alkaline and will clean most brewery equipment. It's easy to wash off and leaves no residue. PBW contains 30% Sodium Metasilicate, a TSP substitute, and 70% Sodium Percarbonate. Those are very good cleaners too. Percarbonate releases Oxygen, leaving washing soda behind.

Sanitation with Iodine products is good, not necessarily inferior to Starsan. Many (US) brewers use Iodophor or similar products. You need to make sure your iodine sanitizer is rinse free, not all are. If not, you'll need to rinse it off after allowing it to do its work. Iodine can be tasted in very small quantities. Your sanitizer being "Povidone-iodine," where is that being used? In breweries? Is it rinse free. maybe the residue is what you're tasting.

Bottled mineral water? Do you know the mineral composition? If the water contains a lot of bicarbonates (HCO3-), it can screw up your mash pH unless you add enough acid to compensate. Other minerals can also let their presence known.

Oxiclean Free (no perfume etc) works OK in a pinch as well if you can get that.

I agree with IslandLizard that it might be high mash pH from bottled mineral water bicarbonate. Do you have access to reverse osmosis or distilled water? If you do then give that a shot.

If you do try RO water and have access to brewing minerals (calcium chloride, gypsum) and also acid/acidulated malt (aka saurmalz) then you can give this a go: https://www.homebrewtalk.com/forum/threads/a-brewing-water-chemistry-primer.198460/
 
If your water contains Chlorine or Chloramines (most municipal water does, it's a sanitizer added during distribution, preventing growth of microorganisms that would make a person sick) you should treat all your brewing water with 1/4 Campden tablet or 1/16 of a teaspoon of Potassium or Sodium Metabisulfite per 5 gallons (20 liters). It's also known as "Meta." Chlorine products form Chlorophenols in your wort, lending a weird plasticky or medicinal taste to your beer. Some bottled water may also contain Chlorine or Chloramines, so smell or taste before use and if detected, treat accordingly.
 
N
I'd leave the dishwash detergent alone when it comes to brewing equipment cleaning.

I'm sure you can buy washing soda, Na2CO3. It's very alkaline and will clean most brewery equipment. It's easy to wash off and leaves no residue. PBW contains 30% Sodium Metasilicate, a TSP substitute, and 70% Sodium Percarbonate. Those are very good cleaners too. Percarbonate releases Oxygen, leaving washing soda behind.

Sanitation with Iodine products is good, not necessarily inferior to Starsan. Many (US) brewers use Iodophor or similar products. You need to make sure your iodine sanitizer is rinse free, not all are. If not, you'll need to rinse it off after allowing it to do its work. Iodine can be tasted in very small quantities. Your sanitizer being "Povidone-iodine," where is that being used? In breweries? Is it rinse free. maybe the residue is what you're tasting.

Bottled mineral water? Do you know the mineral composition? If the water contains a lot of bicarbonates (HCO3-), it can screw up your mash pH unless you add enough acid to compensate. Other minerals can also let their presence known.

Definitely I will change the cleaning product for another more reliable.

This type of povidone iodine is applied in medical procedures, I took 12.5 ppm dilution for no rinse application. However in the last batch I changed by alcohol 70%. But I used the same plastic fermenter bucket of previous batches (partial stained by iodine uses) so I don't know if this slight stain could affect flavor.

I didn't go deep yet about water composition, so that will be a parameter to pay attention for next batches. Thanks
 
Seems everyone got so focused on cleaning as the cause no one has mentioned that 10 of the 16 most common off flavors occur during fermentation. Do you use a yeast starter? Do you use a yeast nutrient? Do you aerate/oxygenate? Do you control your fermentation temperatures? How long is your fermentation period? All of those can contribute to undesirable flavors.
 
Seems everyone got so focused on cleaning as the cause no one has mentioned that 10 of the 16 most common off flavors occur during fermentation. Do you use a yeast starter? Do you use a yeast nutrient? Do you aerate/oxygenate? Do you control your fermentation temperatures? How long is your fermentation period? All of those can contribute to undesirable flavors.

Very valid questions!
The OP did mention he used a temp controlled refrigerator the last 2 times, but the off flavor persists.
 
Seems everyone got so focused on cleaning as the cause no one has mentioned that 10 of the 16 most common off flavors occur during fermentation. Do you use a yeast starter? Do you use a yeast nutrient? Do you aerate/oxygenate? Do you control your fermentation temperatures? How long is your fermentation period? All of those can contribute to undesirable flavors.

I used rehydrated dry yeast (US-05) without yeast nutrient. I did the aeration just shaking the fermenter for a few minutes. Usually the airlock start bubbling after 12 hours and the final OG was reached after 4 days of fermentation, normally I bottled the beer after 10-12 days of fermentation (only primary bucket) plus 2 days of cold crashing.
 
Very valid questions!
The OP did mention he used a temp controlled refrigerator the last 2 times, but the off flavor persists.

If the cause of the off flavor could be excess yeast in suspension, can I decrease it applying cold crashing and gelatin fining? Is there someone who had some experience on this?
 
If the cause of the off flavor could be excess yeast in suspension, can I decrease it applying cold crashing and gelatin fining? Is there someone who had some experience on this?

Suspended yeast in beer manifests itself as haze or cloudiness. Cold crashing with or without gelatin will speed up the process and thoroughness of yeast flocculating out. Now tastewise it may be difficult to detect the difference between a crystal clear (filtered, centrifuged, or extensively cold crashed) beer and one that still has a small amount of residual yeast remaining in suspension, as is common with homebrews. Also some people are much more sensitive to it than others, and could pick it up easily in a triple blind test. However, I doubt most can, though.

US-05 is a slow flocculator, so it may take a week of cold crashing near 0°C (even with a gelatin treatment or 2) to get it as clear as possible. Then when you rack it for bottling or kegging, be careful not to rouse the yeast when lifting and transferring the fermentor. Make sure to start siphoning from the middle of the fermentor and lowering the cane slowly as the beer level drops, taking care not to siphon up any of the yeast from the bottom. Slowly tilting the fermentor toward the end will keep the beer pool deeper, giving you better yield while preventing the yeast from transferring. Stop as soon as cloudy beer starts to transfer.

Not everyone likes the flavor US-05 produces, so that may play a role too. Can you try a different yeast?

Aside from clean, untainted water, quality and freshness of all your ingredients plays a role in the final outcome. Stale malts or extracts, old or poorly stored (cheesy smelling) hops, etc. will affect the final outcome greatly. If you can find other homebrewers or breweries, in your area, taste their beers and let them taste yours and compare. Until we can taste or analyze beer directly over the internet, we're a bit limited here right now in exactly pinpointing the problem.

That detergent-like off flavor as you described, how strong is it? Do you smell it right away when you pour it? When do you taste it, right upfront, or after you swallow?
 
I'll bet you just taste the US 05 still in suspension which tastes crappy.

Was the beer you tasted clear? If not, simply give it some time in the fridge till it dropped out and carefully pour into a glass leaving the yeast with the last sip behind in the bottle.
 
Suspended yeast in beer manifests itself as haze or cloudiness. Cold crashing with or without gelatin will speed up the process and thoroughness of yeast flocculating out. Now tastewise it may be difficult to detect the difference between a crystal clear (filtered, centrifuged, or extensively cold crashed) beer and one that still has a small amount of residual yeast remaining in suspension, as is common with homebrews. Also some people are much more sensitive to it than others, and could pick it up easily in a triple blind test. However, I doubt most can, though.

US-05 is a slow flocculator, so it may take a week of cold crashing near 0°C (even with a gelatin treatment or 2) to get it as clear as possible. Then when you rack it for bottling or kegging, be careful not to rouse the yeast when lifting and transferring the fermentor. Make sure to start siphoning from the middle of the fermentor and lowering the cane slowly as the beer level drops, taking care not to siphon up any of the yeast from the bottom. Slowly tilting the fermentor toward the end will keep the beer pool deeper, giving you better yield while preventing the yeast from transferring. Stop as soon as cloudy beer starts to transfer.

Not everyone likes the flavor US-05 produces, so that may play a role too. Can you try a different yeast?

Aside from clean, untainted water, quality and freshness of all your ingredients plays a role in the final outcome. Stale malts or extracts, old or poorly stored (cheesy smelling) hops, etc. will affect the final outcome greatly. If you can find other homebrewers or breweries, in your area, taste their beers and let them taste yours and compare. Until we can taste or analyze beer directly over the internet, we're a bit limited here right now in exactly pinpointing the problem.

That detergent-like off flavor as you described, how strong is it? Do you smell it right away when you pour it? When do you taste it, right upfront, or after you swallow?

This off flavor like I mentioned in the OP is difficult to match with a typical off flavor but I think is mostly yeasty, sometimes it seems to be detergent but mainly yeasty.

I will try in my next batch with Lallemand Dry-97.
 
I'll bet you just taste the US 05 still in suspension which tastes crappy.

Was the beer you tasted clear? If not, simply give it some time in the fridge till it dropped out and carefully pour into a glass leaving the yeast with the last sip behind in the bottle.
For my previous batches I left the bottles a time in the fridge but the flavor persist. But an interesting fact is that an APA that I made 5 or 6 months ago, I tasted the last bottle that I had in my fridge and this flavor was almost imperceptible. I don't know why but I think could be that suspensed yeast finally drop. Maybe I bottled with excessive yeast.
 
Now tastewise it may be difficult to detect the difference between a crystal clear (filtered, centrifuged, or extensively cold crashed) beer and one that still has a small amount of residual yeast remaining in suspension, as is common with homebrews. Also some people are much more sensitive to it than others, and could pick it up easily in a triple blind test. However, I doubt most can, though.

Do you smell it right away when you pour it? When do you taste it, right upfront, or after you swallow?

This means that the yeast in suspension is hardly a cause of the flavor??

Is possible to smell the off flavor when I pour it, and the flavor is stronger after swallow.
 
If you suspect that suspended yeast may be the culprit, you could try cold-crashing a few bottles in the fridge for several days to get the yeast to settle tight on the bottom. Then very carefully decant into a glass, leaving the yeast slug behind. I'm assuming, of course, that you bottle. :)

Some yeasts add more yeasty flavor than others. US-05 always gives me a little twang, but I'm used to it.
 
For my previous batches I left the bottles a time in the fridge but the flavor persist. But an interesting fact is that an APA that I made 5 or 6 months ago, I tasted the last bottle that I had in my fridge and this flavor was almost imperceptible. I don't know why but I think could be that suspensed yeast finally drop. Maybe I bottled with excessive yeast.

After five months it is unlikely that the yeast is the cause. Have you been very carefull when pouring the glass, not to stir up the yeast at the bottom and leave it instead behind in the bottle together with the last sip?
 
If you suspect that suspended yeast may be the culprit, you could try cold-crashing a few bottles in the fridge for several days to get the yeast to settle tight on the bottom. Then very carefully decant into a glass, leaving the yeast slug behind. I'm assuming, of course, that you bottle. :)

Some yeasts add more yeasty flavor than others. US-05 always gives me a little twang, but I'm used to it.

I can confirm that. Some yeasts taste better to me and some taste worse. US 05 is definitely one of the worst. Together with 3470. I always make sure that they are fully settled before pouring, and really try to be very careful not to disturb the yeast at the bottom of the bottle and leave it there.
 
I can confirm that. Some yeasts taste better to me and some taste worse. US 05 is definitely one of the worst. Together with 3470. I always make sure that they are fully settled before pouring, and really try to be very careful not to disturb the yeast at the bottom of the bottle and leave it there.

I don't mind US-05, but it does have its unique flavor if it gets stirred up. I consider the last ounce of beer in the bottle unusable, and am content with 11 oz. of clear beer in my glass instead of a yeasty 12. Never been a problem as long as I get the bottles in the fridge a few days to crash and pour carefully.

/Die-hard bottler. In before the "you should keg" one-string banjos jump in. :D
 
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