Still having off-flavor issues!

[Sea]

I've posted about this before, but need to vent some frustration again. Ever since I started brewing all-grain about a year and a half ago, Ive had off-flavor issues which I never had in over ten years of doing PM. I can't really put my finger on the flavor, but it's a very slight nastiness at the end.

I'm fairly confident it's not a water quality issue as I had no problems with PM batches using the same water.

I'm pretty sure it's not an infection issue, as my practices haven't really changed, the beer tastes great except for the finish, and I've had no issues with my apfel/fruit wine that i make using the same cleaning/sanitation techniques.

I've gone over my brewing techniques a dozen times, comparing them to many of yours, as well as all the available literature, and finding nothing. I do single infusion batch sparge with no mash out which closely follows Bobby M's well documented techniques. I won't list all my practices, as I've done it several times already here to no avail.

Here's what I've tried so far:

I've tested my thermometers multiple times
Ive tested my mash conversion
I've tried different mash temps
I've tried higher and lower sparge temps
I've replace my corrona mill with a barley crusher
I've used smack packs, smack packs with a starter, Dry yeast, and rehydrated dry yeast (mostly S0-5)
I've tried higher and lower ferm temps
I'm sure there's more I can't think of right now.....

There have been many good suggestions from all of you, but no improvement. The beer is drinkable, but that aftertaste.... It's driving me crazy!

I just don't know what to do any more, and I'm too damn stubborn to go back to PM.

The thoughts which keep rolling around in the back of my brain are these:

Could the cleaner I use (TSP, which I rinse VERY well) be leaving some residue?
Could my mash/sparge temps still somehow be too high (tannins)?
Could it just be that I'm not getting good oxygenation and the yeast is causing the off-flavor (I splash heavily when transferring to fermenter, then shake the fermenter vigorously for several minutes)?
Could I still some how have too high of ferm temps (never gotten above 72, mostly around 68, last brew at 64!)?
I'm effing tired of doing all the work for a hobby which I love but not reaping the rewards.

Sorry for the rant.

 

[permo]

Try a brew with bottled water and see what happens. The two things that come to mind would be too high a sparge temp extracting bitterness and your water hardness. I had some of the same bitterness in my brews when I was an idiot and added gypsum to my water. The good thing is that it faded over time..months of time. I no longer add gypsum and my beers are awesome.

 

[[email protected]]

Discribe the after taste.

 

[WenValley]

Do others notice the taste too?

Do you have nearby brew friends that can either come to your place to brew a batch, or you go to their place to brew a batch? Or both? Either way you'll learn something that will help you solve this mystery.

I'm presuming that you're getting this same off flavor all across your brewing spectrum.

 

[jmo88]

Is there a common thread with the ingredients? Do you always use a particular yeast or hop? A descriptive taste or aroma would help.

 

[waldoar15]

Might be DMS. You could try a longer boil next time and see if it's still there.

 

[moger777]

I'm a big fan of putting buffer 5.2 in my beers. When I started doing ag, I had a bit of bitter astringency in my beers. The 5.2 seemed to help, also made my efficiency better. Have you tried going back to extract/partial mash since going all grain? It could be a coincidence that you are getting off flavors. Cracks in the plastic of your equipment could cause infection. Also, I've found all grain does benefit to a bit more aging (a week or two, not much more) due to the increased "graininess" of the wart.
-Thijs

 

[Revvy]

I definitely don't think using trisodium phosphate is a good idea to clean your bottles, is it even SAFE to use in and around food?

I don;t know if that's a cause, but I wouldn't put it past being so, regardless I would stop using it immediately and use oxyclean or pbr.

You haven't stated how long you let your beers bottle/keg condition before drinking them either.

 

[Revvy]

From the TSP Material Data Safety Sheet.

Warnings: Keep away from children.

Emergency And First Aid Procedures
Eyes: Flush Toughly With Water. Obtain Medical Attention.
Skin: Wash Off With Water. If Irritation Is Evident, Obtain Medical Attention.
Inhaled: Remove From Exposure. If Breathing Is Difficult Or Discomfort
Persists, Obtain Medical Attention.
Swallowed: Rinse Mouth With Water, Give Water To Cause Particles To Dissolve. Do Not Cause Vomiting. Call A Physician Immediately.
Acute Health Effects: From MSDS
Inhalation Health Risks And Symptoms Of Exposure
Small Amounts Of Dust Are Very Irritating. Large Exposures Can Cause Tissue
Burns.

Skin And Eye Contact Health Risks And Symptoms Of Exposure
Eye Contact: Tissue Burns Are Likely.
Skin Contact: Strong Irritant; Chemical Burns Are Possible.

Skin Absorption Health Risks And Symptoms Of Exposure
Not Known.

Ingestion Health Risks And Symptoms Of Exposure
Slightly Toxic (Due To High Ph).

Health Hazards (Acute And Chronic)
Acute: The Material Is Moderately Toxic To Humans. Inhalation Of Heavy Dust
May Irritate Nose And Throat. Ingestion May Injure Mouth, Throat, And
Gastrointestinal Tract. Contact With Eyes Produces Local Irritation And
Possible Conjunctivitis.
Chronic: Chronic Toxicity Is Known, But Is Not Believed To Be Significant For
Low Concentration.

Medical Conditions Generally Aggravated By Exposure: Skin Irritation May Be Aggravated In Persons With Existing Skin Lesions. Breathing Of Dust May Aggravate Acute Or Chronic Asthma And Other Chronic Pulmonary Disease.
Chronic Health Effects: From MSDS
Chronic Toxicity Is Known, But Is Not Believed To Be Significant For Low Concentration.
Carcinogenicity: From MSDS
Neither the NTP, IARC, nor OSHA lists trisodium phosphate as a carcinogen.

I don't think I'd be brewing with it.

 

[JoMarky]

That's pretty similar to star san's MSDS

 

[remilard]

TSP is a common cleaning agent for food applications and no more dangerous than others, in general. It used to be in almost all laundry and dish washing detergents used in homes, but was removed over environmental and not safety concerns.

And for the requisite appeal to authority: Palmer says it is safe in How To Brew.

 

[Sea]

Try a brew with bottled water and see what happens. The two things that come to mind would be too high a sparge temp extracting bitterness and your water hardness. I had some of the same bitterness in my brews when I was an idiot and added gypsum to my water. The good thing is that it faded over time..months of time. I no longer add gypsum and my beers are awesome.

The water quality here is excellent. The biannual water report i receive from the local water commission puts my water right where you'd want it to be for brewing American ales. Besides, I never had this issue before going AG using the same water.

Discribe the after taste.

God, I wish I could. I've poured over the descriptions i could find of off-flavors in beer and I'm just not sure, but I think it's somewhere around sourness/astringency/maybe slightly feusal? These are all isues I've addressed in my brewing practices with no cnange.

Do others notice the taste too?

Do you have nearby brew friends that can either come to your place to brew a batch, or you go to their place to brew a batch? Or both? Either way you'll learn something that will help you solve this mystery.

I'm presuming that you're getting this same off flavor all across your brewing spectrum.

i need to do this. Yes others can taste it, though many are nice and say it tastes great. I haven't had the opportunity to share my beer with a highly experienced brewer and get their opinion yet.

Is there a common thread with the ingredients? Do you always use a particular yeast or hop? A descriptive taste or aroma would help.

Here are a couple threads I've posted about the problem:

https://www.homebrewtalk.com/f36/few-technique-questions-gurus-133470/

https://www.homebrewtalk.com/f13/flavor-changing-over-time-worse-83446/

Different hops, different yeasts (wet, dry, starter, rehydrated), though I use Safeale S-05 more often than any other.

Might be DMS. You could try a longer boil next time and see if it's still there.

I've thought about this, but why would a 60 min rolling boil not work for me when it works for most everyone else?

I'm a big fan of putting buffer 5.2 in my beers. When I started doing ag, I had a bit of bitter astringency in my beers. The 5.2 seemed to help, also made my efficiency better. Have you tried going back to extract/partial mash since going all grain? It could be a coincidence that you are getting off flavors. Cracks in the plastic of your equipment could cause infection. Also, I've found all grain does benefit to a bit more aging (a week or two, not much more) due to the increased "graininess" of the wart.
-Thijs

I've been using 5.2, and it doesn't seem to make a difference whether I do or not.

I definitely don't think using trisodium phosphate is a good idea to clean your bottles, is it even SAFE to use in and around food?

I don;t know if that's a cause, but I wouldn't put it past being so, regardless I would stop using it immediately and use oxyclean or pbr.

You haven't stated how long you let your beers bottle/keg condition before drinking them either.

It's a common cleaning agent for homebrewers, and I started using it on the recomendation of my LHBS. I will probably order some PBW just to eliminate the possibility though. i'm at the point where i'll try anything.

I mostly make ales, and they sit for usually 4-6 weeks between primary/secondary (sometimes)/keg before I tap. After that it's usually a couple of months or more before I'll finish it.

TSP is a common cleaning agent for food applications and no more dangerous than others, in general. It used to be in almost all laundry and dish washing detergents used in homes, but was removed over environmental and not safety concerns.

And for the requisite appeal to authority: Palmer says it is safe in How To Brew.

yeah, a lot of homebrewers use it. I was told it leaves no residue when rinsed properly, but maybe that's incorrect. Before my next batch I will clean everything with a different agent just to be sure.



I appreciate all the ideas.

 

[samc]

How do commercial beers taste to you?

Simply asking just to rule out your taste bud changes, sinus troubles or other medical things that interfere with taste.

You really need to have someone taste your beer - LHBS? Brew club members?

 

[Austinhomebrew]

It is All-Grain Twang. J/K

Usually it is a cleaner issue. Try a no rinse one time.

Forrest

 

[android]

i know that people feel TSP is ok to use, but i used to use that stuff to clean paint machines in a former life. there's no question about it's cleaning ability, but IMHO, that stuff always left a noticeable film on everything, despite a really hot rinse. anyway, you might just try and see if that has any effect on a future brew.

 

[GNBrews]

I'd blame it on the water first. Get some pH strips or a meter and test the water you're using in the brew. My tap water varies seasonally somewhere ~8.5-9.1. I've started adding pH 5.2 buffer, and my beers lost that "homebrew" flavor.

 

[bakins]

FWIW, I still have the same issue as you. If I do all-grain, I get a harshness in the finish - kinda hard to describe, but it's not astringent or DMS (from the definitions I've read). If I do a PM with 75% of the fermentables from grain, it all tastes fine - good to great to me at least. I tried everything: water, sanitizer, fermentation temp, mash temps, etc. but my PM beers kept being good, my AG so-so at best. So, I just stopped worrying about it and use light DME for about 25% of the fermentables in all my recipes

 

[bradjoiner]

i had a simalar problkem and it turned out to b the water. if you havent tryed bottled spring water you should definatly do so. if nothing else you should at least boil with campden to make sure all chlorine is removed. sparging grains is diferent than steeping specialty grains. i am able to do extract with my local water but am not able to do all grain unless i boil the water with campden for about fifteen minutes before i mash and sparge my grains

 

[Sea]

How do commercial beers taste to you?

Simply asking just to rule out your taste bud changes, sinus troubles or other medical things that interfere with taste.

You really need to have someone taste your beer - LHBS? Brew club members?

I wish it were this simple, but commercial beers (while there are many I can't stand) still taste great.

It is All-Grain Twang. J/K

Usually it is a cleaner issue. Try a no rinse one time.

Forrest

i know that people feel TSP is ok to use, but i used to use that stuff to clean paint machines in a former life. there's no question about it's cleaning ability, but IMHO, that stuff always left a noticeable film on everything, despite a really hot rinse. anyway, you might just try and see if that has any effect on a future brew.

This is definitely what I'll change on the next batch. I've been using TSP for a long time, so i'll have to thoroughly clean everything with a new agent beforehand.

I'd blame it on the water first. Get some pH strips or a meter and test the water you're using in the brew. My tap water varies seasonally somewhere ~8.5-9.1. I've started adding pH 5.2 buffer, and my beers lost that "homebrew" flavor.

If changing my cleaner has no effect, I'll try water next. I highly doubt it's the problem, but I'll try anything. Our city water is local spring water, barely treated, ph of 6.8-7.2 with normal levels of everything.

FWIW, I still have the same issue as you. If I do all-grain, I get a harshness in the finish - kinda hard to describe, but it's not astringent or DMS (from the definitions I've read). If I do a PM with 75% of the fermentables from grain, it all tastes fine - good to great to me at least. I tried everything: water, sanitizer, fermentation temp, mash temps, etc. but my PM beers kept being good, my AG so-so at best. So, I just stopped worrying about it and use light DME for about 25% of the fermentables in all my recipes

Good to hear I'm not alone. it sucks when you put this much effort into something, been doing it for this long, and while everyone else says don't worry about it, your beer will turn out great, it doesn't.

Well, I'm going to figure it out if it kills me, so I'll let you know if I find anything.

i had a simalar problkem and it turned out to b the water. if you havent tryed bottled spring water you should definatly do so. if nothing else you should at least boil with campden to make sure all chlorine is removed. sparging grains is diferent than steeping specialty grains. i am able to do extract with my local water but am not able to do all grain unless i boil the water with campden for about fifteen minutes before i mash and sparge my grains

Interesting. Well, I will play around with this in the next few batches

 

[-TH-]

Our city water is local spring water, barely treated, ph of 6.8-7.2 with normal levels of everything.

Can you post your water specs?

 

[bakins]

Good to hear I'm not alone. it sucks when you put this much effort into something, been doing it for this long, and while everyone else says don't worry about it, your beer will turn out great, it doesn't.

FWIW, I tried building my own water up from distilled/RO and that didn't help. I just figure I'm cursed I got tired of dumping batches. Like I said, I just stopped worrying about it and do "mostly grain" partial mashes now. I do an AG batch every once in a while, but they are never quite "right."

 

[smizak]

Might be DMS. You could try a longer boil next time and see if it's still there.

Gonna bump that. I'm convinced that a lot of the "my extract/PM's were fine but my all-grain sucks" complaints are because of DMS. What kind of boil do you get?

 

[OLDBREW]

It is definitely not the TSP if you are rinsing properly. TSP rinses clear in hot or cold water so forget about that. BOS at National level have used TSP as their cleaning solution

My question is what have you changed as far as equipment is concerned since you switched over from partial mashes to all grain mashes? Are you using different equipment like tubing for vorlauf and transfering the mash. Is your vessel(s different then before? Are you using all high temperature tubing, gasket/o-ring/sealants and are sure nothing could be leaching into the wort that way?

Are you aware that when using extracts, your hop utilization isn't as high as when using hops in all grain, and you have to cut back the quanity in your all grain recipes?

What quality and age are the malts you are using? Pre milled or whole malt you mill yourself?

Like someone pointed out.. Try a batch with bottled water only see if that changes.

The other thing is if you are used to extract you are used to a less fermentable wort.

Try your saach rest up at 158*F and see if that off flavor gets cloaked some.

 

[Sea]

Can you post your water specs?

I'll Try to do this later.

Gonna bump that. I'm convinced that a lot of the "my extract/PM's were fine but my all-grain sucks" complaints are because of DMS. What kind of boil do you get?

I guess it my be possible, but I get a nice rolling boil on a propane burner for a full hour, and of course never cover my boil kettle. So why would I have that problem when everyone else doesn't?

It is definitely not the TSP if you are rinsing properly. TSP rinses clear in hot or cold water so forget about that. BOS at National level have used TSP as their cleaning solution

My question is what have you changed as far as equipment is concerned since you switched over from partial mashes to all grain mashes? Are you using different equipment like tubing for vorlauf and transfering the mash. Is your vessel(s different then before? Are you using all high temperature tubing, gasket/o-ring/sealants and are sure nothing could be leaching into the wort that way?

Are you aware that when using extracts, your hop utilization isn't as high as when using hops in all grain, and you have to cut back the quanity in your all grain recipes?

What quality and age are the malts you are using? Pre milled or whole malt you mill yourself?

Like someone pointed out.. Try a batch with bottled water only see if that changes.

The other thing is if you are used to extract you are used to a less fermentable wort.

Try your saach rest up at 158*F and see if that off flavor gets cloaked some.

Yeah I use TSP at 1 tsp/gal, and always rinse very well.

Everything has changed equipment wise since I went all grain, so it'd be pretty hard to put a finger on the differences. I mash in a Rubbermaid 10 gal cooler, boil on a turkey fryer in a converted keggle with welded couplings. Chill with a copper imersion chiller. There may be a few small parts in my mash tun which aren't rated for high temps, I'll have to check that. Am I sure there's nothing leaching nasties into my beer? No. Can you ever be sure? If that is the problem it's tenacious as I've done about a dozen batches with this setup.

Hop utilization is definitely not the issue. I've brewed several of the recipes on this site's database which got rave reviews and had the same problem.

My grain is always fresh, I mill my own with my recently purchased Barley Crusher, and before that a hand-me-doen corona mill.

My latest batch a mashed at about 156-157, so we'll see, but it had the flavor going into the secondary for dry-hopping. Plus I want to solve the problem not just mask it.

Thanks for all the suggestions.

 

[bakins]

Are you aware that when using extracts, your hop utilization isn't as high as when using hops in all grain, and you have to cut back the quanity in your all grain recipes?

If he's doing full boils when doing extract or PM, it shouldn't matter.

 

[Wellshooter]

Could it be on the dispensing side. Some plastics have an ugly finish if you drink water through them. Like walmart garden hose?

 

[smizak]

I would try your next AG batch using bottled water.

I know you said that your PM/extracts turned out fine with it, but you use a lot more water with AG. At least you could scratch it off the list permanently if it still tasted weird. Your process looks airtight, it's the only thing I can think of now.

 

[OLDBREW]

Everything has changed equipment wise since I went all grain, so it'd be pretty hard to put a finger on the differences. I mash in a Rubbermaid 10 gal cooler, boil on a turkey fryer in a converted keggle with welded couplings. Chill with a copper imersion chiller. There may be a few small parts in my mash tun which aren't rated for high temps, I'll have to check that. Am I sure there's nothing leaching nasties into my beer? No. Can you ever be sure? If that is the problem it's tenacious as I've done about a dozen batches with this setup.

Okay so if we break down your setup when you put the cooler mash tun together did you use silicon/teflon o-rings or did you use just some rubber o-rings that isn't designed for food grade use at 180*? How about the vinyl tubing is it rated at 180* or is it some box store tubing that is only rated for 110*? That stuff can produce off flavors!

Sounds like your keggle is pretty much okay and the copper chiller if there were any oils or machining residuals, they would have come out in the first batch of brew being the wort is acidic.

I'd just swap out any parts in the cooler that are questionable.

When I was saying cloaking, what my thought was, if you had this with you partial mash brews but the extract hid the off flavor, then bumping up the mash temp may do the same.

Next step would be trying different water if it is not something covered

 

[JesseRC]

Could it be on the dispensing side. Some plastics have an ugly finish if you drink water through them. Like walmart garden hose?

I've had this happen. I made an Heffe with orange zest in the boil. After the keg kicked and I cleaned my keg lines with pbw and starsan. I then tapped my cream ale and it had the same after taste of orange zest. You might want try some pints using a different picnic tap just to see.

 

[Ohio-Ed]

Here's my suggestion...
Run through your entire process; brewing / bottling / distribution with water and no other ingredients. Take samples after each step including the water you start with. If the samples don't taste like water, then you have narrowed your search. A big advantage to this process is you don't have to wait on anything to ferment. If in the end, the water still tastes like water, then your issue is likely related to ingredients (or the handling of ingredients)

I went through this over the summer (not the bottling/kegging part but all the brewing process including cooling) and was surprised how the water changed through the process. I took samples every time the water went from one piece of equipment to the next. In the end I had about 6 or 8 samples.

It will take a bit of time, but won't cost much and might be very enlightening.

I'm working on a new system now and this will be one of the first things through it... right after cleaner and rinse.

Good luck,

Ed

 

[smizak]

Here's my suggestion...
Run through your entire process; brewing / bottling / distribution with water and no other ingredients. Take samples after each step including the water you start with. If the samples don't taste like water, then you have narrowed your search. A big advantage to this process is you don't have to wait on anything to ferment. If in the end, the water still tastes like water, then your issue is likely related to ingredients (or the handling of ingredients)

I went through this over the summer (not the bottling/kegging part but all the brewing process including cooling) and was surprised how the water changed through the process. I took samples every time the water went from one piece of equipment to the next. In the end I had about 6 or 8 samples.

It will take a bit of time, but won't cost much and might be very enlightening.

I'm working on a new system now and this will be one of the first things through it... right after cleaner and rinse.

Good luck,

Ed

Good advice.

 

[JuanMoore]

Here's my suggestion...
Run through your entire process; brewing / bottling / distribution with water and no other ingredients. Take samples after each step including the water you start with. If the samples don't taste like water, then you have narrowed your search. A big advantage to this process is you don't have to wait on anything to ferment. If in the end, the water still tastes like water, then your issue is likely related to ingredients (or the handling of ingredients)

I went through this over the summer (not the bottling/kegging part but all the brewing process including cooling) and was surprised how the water changed through the process. I took samples every time the water went from one piece of equipment to the next. In the end I had about 6 or 8 samples.

It will take a bit of time, but won't cost much and might be very enlightening.

I'm working on a new system now and this will be one of the first things through it... right after cleaner and rinse.

Good luck,

Ed

+1 excellent suggestion.

 

[Sea]

I just looked at my first post, and realized that I wasn't as clear as i meant to be. The off flavor is first detected after fermentation, when I transfer out of primary, into keg/secondary, and stays with the beer from then on. I'm confident it's not in dispensing. I'm becoming more confident it's not anything to do with my cleaning/sanitizing process.

I always taste my hydro sample into the fermenter, and don't detect anything but sweet hoppiness. I don't know if the sugar would mask the flavor or not, but fermentation seems to be the key element that either amplifies something which happens during the brewing process, or causes the problem altogether. And yes, I closely monitor and control my ferm temps.

Could it be on the dispensing side. Some plastics have an ugly finish if you drink water through them. Like walmart garden hose?

See above.

I would try your next AG batch using bottled water.

I know you said that your PM/extracts turned out fine with it, but you use a lot more water with AG. At least you could scratch it off the list permanently if it still tasted weird. Your process looks airtight, it's the only thing I can think of now.

This is on the list, though I still doubt it's the culprit in my case.

Okay so if we break down your setup when you put the cooler mash tun together did you use silicon/teflon o-rings or did you use just some rubber o-rings that isn't designed for food grade use at 180*? How about the vinyl tubing is it rated at 180* or is it some box store tubing that is only rated for 110*? That stuff can produce off flavors!

Sounds like your keggle is pretty much okay and the copper chiller if there were any oils or machining residuals, they would have come out in the first batch of brew being the wort is acidic.

I'd just swap out any parts in the cooler that are questionable.

When I was saying cloaking, what my thought was, if you had this with you partial mash brews but the extract hid the off flavor, then bumping up the mash temp may do the same.

Next step would be trying different water if it is not something covered

I still need to check over my tun, there could be some issues there.

Here's my suggestion...
Run through your entire process; brewing / bottling / distribution with water and no other ingredients. Take samples after each step including the water you start with. If the samples don't taste like water, then you have narrowed your search. A big advantage to this process is you don't have to wait on anything to ferment. If in the end, the water still tastes like water, then your issue is likely related to ingredients (or the handling of ingredients)

I went through this over the summer (not the bottling/kegging part but all the brewing process including cooling) and was surprised how the water changed through the process. I took samples every time the water went from one piece of equipment to the next. In the end I had about 6 or 8 samples.

It will take a bit of time, but won't cost much and might be very enlightening.

I'm working on a new system now and this will be one of the first things through it... right after cleaner and rinse.

Good luck,

Ed

This is a good suggestion. I willy this when I have time.

 

[markg388]

Sorry if I missed whether or not you tried a 90-minute boil yet, but all I saw was "why would my beer taste wierd with a 60 minute boil when everyone else's is fine?". My beers often had off-flavors with 60 minute boils (for no reason in particular) until i ramped it up and it was fixed, so I'd try that first. I started doing 90 minute boils and using bottled water to get rid of my off flavors (those big 2.5 gallon ones with the spigot) and it worked.

Your boiling vessel is stainless steel right?

 

[CharlosCarlies]

I've tried higher and lower sparge temps

Have you tried different mash thicknesses? Since I've started mashing thin (2qt/lb+), my beers have become significantly better. I'm guessing this is because of the smaller sparge volume (and FWIW my efficiency has actually improved). Might not make a difference for you but it can't hurt to try.

 

[bradjoiner]

Okay so if we break down your setup when you put the cooler mash tun together did you use silicon/teflon o-rings or did you use just some rubber o-rings that isn't designed for food grade use at 180*? How about the vinyl tubing is it rated at 180* or is it some box store tubing that is only rated for 110*? That stuff can produce off flavors!

Sounds like your keggle is pretty much okay and the copper chiller if there were any oils or machining residuals, they would have come out in the first batch of brew being the wort is acidic.

I'd just swap out any parts in the cooler that are questionable.

When I was saying cloaking, what my thought was, if you had this with you partial mash brews but the extract hid the off flavor, then bumping up the mash temp may do the same.

Next step would be trying different water if it is not something covered

i acvtually tried this today and was very suprised by the results. athough i did not pick up anything i would call an off flavor i did pick up hints of maltiness comng out of my cooler mash tun. and also a weird flavor that came from my immersion chiller. i recomend his to every one. (to solve the chiller problem i boiled in a vinegar solution)

 

[bradjoiner]

i acvtually tried this today and was very suprised by the results. athough i did not pick up anything i would call an off flavor i did pick up hints of maltiness comng out of my cooler mash tun. and also a weird flavor that came from my immersion chiller. i recomend his to every one. (to solve the chiller problem i boiled in a vinegar solution)

sorry i meant to quote ohio-ed's advice on running the brew process with just water but i messed up and now i cant fix my post

 

[Dr Malt]

There are some great comments and advise here and it appears you are well on your way pursuing these in an attempt to solve your problem. I have a few things to add that might be helpful.

In terms of it being DMS, I don't think this is your problem in that the flavor of DMS is more vegetable, corn like and sometime sweet. And how you might get DMS from a 60 minute boil versus others who get none from a 60 minute boil has to do with how long it takes to cool your wort after boil. Hot, non-boiling wort continues to form DMS and without a boil, it is not as readily driven off. Thus it builds up in the wort. The cooler the wort, the slower the reaction is in forming DMS. So if your wort was sitting at 180 F for 30 minutes and another brewer cooled his wort to 68 F in 30 minutes and both boiled for 60 minutes, your wort would have a much higher DMS level in the wort and beer compared to the other brewer.

The flavors you describe, sour, astringency, feusal (I assume fusel not fecal) can have different origins. The sour flavor can be from acid producing bacteria which is a contamination. Astringency is normally from the tannins in the grain. I see you are sparging with 190 F water and you said you have lowered that some to prevent extracting tannins. You might check your sparge water pH. Tannins are acidic so sparge water above 7 will solubilize and extract more tannins. If your sparge water is slightly acidic ( less than 7 such as 6.0 - 6.8), you will get less tannin extraction. Also, as you sparge the grain, the pH is rising to that of the water the more you rinse. Don't worry about getting maximum efficiency as the last bit of extract can come with a good shot of tannins.

Fusel oils are can be formed by yeast or bacteria during fermentation. If your fermentation temperatures are above 70 F you can get fusel oils from yeast. However, it sounds like you control your fermentation temperatures well so would not suspect this to be a problem.

One other thought is that an array of off flavors can come from hydrolyzed yeast. This can be a bitterness that is more lingering and different than hop bitterness. This happens when the beer sits on the yeast and/or settled yeast that has hydrolyzed is stirred into the beer somehow. This is a nasty after taste in beer. Do you carefully rack the beer off the yeast cake after primary and secondary fermentation?? Just a thought.

I hope this helps some. Keep up the detective work, you will find the problem!

Dr Malt

 

[martinworswick]

do you take any gravity readings towards the end of the sparge?

 

[cubbies]

I'm gonna throw my hat in the DMS arena, I would try a 90 minute boil. I am sure u have an extra 30 minutes on brewday. Its worth a shot.