Astringent Off-flavor

[Renaveg]

I'm an all grain brewer and I have been brewing for about 4 years now and for the last year I have noticed a strange astringency to my beers and it seems to be more in the after-taste. I've been trying to narrow it down but I'm still having the problem so I thought I would post here.

I thought maybe there was an infection somewhere so I cleaned and sanitized everything with PBW and Starsan, but that didn't help. I also thought maybe it was some contaminated CO2 or a bad tank since I started using a new tank around the time that I noticed the problem so I made some seltzer water and it tasted fine so I'm pretty sure it's not that. Then I thought maybe it was my water or water additions but I've tried no additions with filtered water and no additions with RO water and it still didn't seem to make a difference.

I brew mostly IPA's and IIPA's, but I did notice when I brewed my pumpkin ale that it wasn't as astringent and I'm wondering if maybe some grain husks are getting into my boil causing the astringency and it wasn't as big of a problem with the pumpkin ale because the pumpkin in the mash helped strain the grains out. On my next batch I'm going to strain the run-off through a mesh bag to see if that helps.

Any thoughts?

Thanks,
Dave

My Setup
10 gallon Rubbermaid cooler/mash-tun
15 gallon stainless full-boil kettle
6 1/2 gallon glass carboy fermenter
chest freezer converted fermentation fridge
stainless kegs

 

[Yooper]

The first thing that jumps out at me is bicarbonate/alkalinity in the brewing water. That is most often the cause of astrigency, especially in light colored beers.

Have you checked your mash pH?

 

[Renaveg]

I haven't checked my mash pH, but I have had my water tested and I adjust using Brun water, but I've also used RO water and had the same issue.

 

[BryceL]

I haven't checked my mash pH, but I have had my water tested and I adjust using Brun water, but I've also used RO water and had the same issue.

Not sure where you live, but here in drought stricken California, there is no guarantee where the City's are pulling their water from anymore. If you haven't had your water tested in a while, you might consider another test...if you suspect it might be a water issue. And as Yooper pointed out, it will likely be more evident in light colored beers.

 

[GHBWNY]

Don't know if any of these conditions apply to anything you're doing differently in your brewing process in the last year, but FWIW, here's what Palmer says about it:

"Astringency... is often the result of steeping grains too long or when the pH of the mash exceeds the range of 5.2 - 5.6. Oversparging the mash or using water that is too hot are common causes for exceeding the mash pH range. It can also be caused by over-hopping during either the bittering or finishing stages. Bacterial infections can also cause astringency, i.e. vinegar tones from aceto bacteria.

The brown scum that forms during fermentation and clings to the side of the fermentor is intensely bitter and if it is stirred back into the beer it will cause very astringent tastes. The scum should be removed from the beer, either by letting it cling undisturbed to the sides of an oversize fermentor, or by skimming it off the krausen, or blowing off the krausen itself from a 5 gallon carboy. I have never had any problems by simply letting it cling to the sides of the fermentor."

 

[jtp137]

How is your crush? What do you have in mash tun false bottom, or mesh screen. Are you getting a lot of bits in the boil

 

[Renaveg]

I was thinking water from the beginning, but since I have used RO with no additions and still had the same problem, I think I've ruled that out. That being said I did use acidulated malt to bring my mash pH to 5.3 using Brun water.

I hadn't thought much about the krausen thing, but my process hasn't changed and I usually cold crash.

I've tried recipes that I've brewed successfully in the past and I still have the same problem so I also don't think it's the hopping.

It may have something to do with my mash process as I did start to notice it when I went from BIAB to all grain in the cooler, but it wasn't exactly at the same time, but it may have been hidden by beer type?

Do you think a small amount of husks making it into the boil would cause a noticeable astringency?

 

[Renaveg]

I also put everything into the fermenter from the boil, but I don't think that's causing it as I've always done that and even when I didn't do it I still noticed it.

 

[Renaveg]

I order it crushed through NB so I don't think it's too fine. I use a stainless bazooka tube and I do get some bits in the boil, but not a ton. If I had to guess there is probably a couple of dozen pieces floating at the beginning of the boil.

It's funny I picked up a growler of an IIPA at a local brewer this weekend and wasn't able to finish it the first day and when I had some today it had a similar taste so I'm wondering if O2 might be the problem. I like to think that i'm pretty careful about O2, I flush all vessels with CO2 and I push all of my beer with CO2, but the taste is very similar. I normally transfer from brew kettle to fermenter at 80 degrees, maybe I should let it cool more?

 

[jtp137]

What is your bittering hop

 

[Renaveg]

It varies based on the recipe, it's always either pellet hops or hopshots as is the case with some of the NB kits like Plinian and Off The Topper.

 

[Renaveg]

I was looking at the posts from the other night and I'm wondering if maybe it has something to do with an improper pH of the sparge water which wouldn't have been a problem when I was doing BIAB. This may be my next experiment.

 

[beerkench]

Do you use dry yeast?


Sent from hell
using Home Brew

 

[Renaveg]

I use both. I actually split one batch to see if that was the problem and they both had the same off-taste.

 

[p_p]

Just to through something else in the mix.

Are you positive it is astringency you are tasting? Do you feel it all the way through the life of the beer?
Could it be some sort of flavor clash between darker/crystal grains and the hops?

 

[stpug]

Oversparging the mash or using water that is too hot are common causes

I personally ran into a string of lightly astringent beers not too long back that were caused by oversparging and/or sparge water temps. I resolved the issue by sparging less and keeping my sparge water temperature in check (165ish). I have not experienced the astringency since making these changes, and the overall malt flavor qualities have improved. They resulted in a slightly lower efficiency but I'm okay with that since the overall efficiency is still pretty high (went from 84% to 80% fermenter efficiency).

I use a couple different techniques for sparging based on my grainbill and water ratio. Sometimes it's a single batch sparge and other times it's a sprinkle sparge (pseudo-fly sparge); the latter is used for small grainbills and/or high water ratio mashes (i.e. grainbills that are easily converted and rinsed).

 

[brick_haus]

I had the same problem, seriously. I opened up my mill a little (.038 to .042), decreased my sparge temp from 170-172 to 165-168. No more astringency.
I have always used RO water with salt additions and closely monitored pH, so I knew that those were not the issue.

 

[Renaveg]

It's definitely astringency and I taste it through the life of the beer. I can't say if it gets better or worse as it ages, but I would almost say it gets worse. I know this would suggest infection, but I've never seen any signs of infection.

I normally batch spare in two steps using Beersmith and I try to hit a 170 mashout which sometimes means I'm adding a small amount of 212 degree water to hit 170. I stir constantly while adding and I usually hit around 168. maybe I should just skip the washout and only add 168 water to sparge?

I haven't got a grain mill so I'll have to rely on NB for now, but I would think if they had an issue we'd hear more about it.

 

[Yooper]

It's definitely astringency and I taste it through the life of the beer. I can't say if it gets better or worse as it ages, but I would almost say it gets worse. I know this would suggest infection, but I've never seen any signs of infection.

I normally batch spare in two steps using Beersmith and I try to hit a 170 mashout which sometimes means I'm adding a small amount of 212 degree water to hit 170. I stir constantly while adding and I usually hit around 168. maybe I should just skip the washout and only add 168 water to sparge?

I haven't got a grain mill so I'll have to rely on NB for now, but I would think if they had an issue we'd hear more about it.

No, that all seems fine.

You said you've tried all RO water and using some acid malt (or acid) in the mash? And sparging with 100% RO water?

 

[WenValley]

Your situation sounds almost exactly like what I went through a couple of months ago. I ended up dumping out over 20 gallons of beer that has that "astringency".


Mine was sanitation and I know you have considered that issue. But I gotta tell you that what you described fits my recent problem to a "T".

Search back on my posts.

I declared "nuclear" war in my brew room.

Best of luck, it's really frustrating.

I had to "rebrew" thirty gallons of beer to catch back up and I'm happy to report that the beer is back up the the high standard that we set here.

 

[stpug]

It's definitely astringency and I taste it through the life of the beer. I can't say if it gets better or worse as it ages, but I would almost say it gets worse. I know this would suggest infection, but I've never seen any signs of infection.

I normally batch spare in two steps using Beersmith and I try to hit a 170 mashout which sometimes means I'm adding a small amount of 212 degree water to hit 170. I stir constantly while adding and I usually hit around 168. maybe I should just skip the washout and only add 168 water to sparge?

I haven't got a grain mill so I'll have to rely on NB for now, but I would think if they had an issue we'd hear more about it.

If you sparge just once then I would not worry too much about your process causing astringency, but if you're sparging twice then you may be experiencing what I did which was resolved by just sparging once. Your sparge water's pH can play a big role in extracting astringency from grain husk. I'm a believer in sparge water that's treated for pH to reduce it's potential impact.

 

[Renaveg]

Yes, I tried brewing with straight RO, no salts and just enough acidulated malt to hit my mash pH and then sparged with straight RO. So basically my sparge water would have had a pH of 7. Not sure if that's high enough to make a difference, but maybe.

WenValley - I think you might be right and I'm going to go through all of my gear and replace all of my hoses. I normally clean with PBW and/or Oxy Free, do you think for this one-time ultimate cleaning I should use bleach?

 

[joshesmusica]

Yes, I tried brewing with straight RO, no salts and just enough acidulated malt to hit my mash pH and then sparged with straight RO. So basically my sparge water would have had a pH of 7. Not sure if that's high enough to make a difference, but maybe.

WenValley - I think you might be right and I'm going to go through all of my gear and replace all of my hoses. I normally clean with PBW and/or Oxy Free, do you think for this one-time ultimate cleaning I should use bleach?

When I read the first few posts, my first thought was your sparge water. As yooper always says, astringency will come from both high pH and high temp in your sparge water, so if your temps aren't too high, then that's not your issue. But I'm guessing that your sparge has a pretty high pH, especially since you're batch sparging twice.

 

[WenValley]

Renaveg:

I wouldn't hesitate to throw the bleach bomb.

I've been brewing a long time, and I was pretty sure my sanitation procedures were up to speed.

But when I did a "fresh eyes" review I was substandard in several areas. Just cut too many corners.

Oxyclean and Starsan are your friends. Bleach is your hired gun.

I kept hoping my beers would get better and that the odd flavor would fade.

Then I started thinking about "masking" the odd flavor. I finally slapped myself and asked "do I want to serve beer where I had to hide off flavors"?

The answer as simple, but it was a sad day dumping out four full kegs of beer.

Best of luck....

 

[Renaveg]

I think you're right. As much as I hate to change more than one thing at a time, I'm going to clean the hell out of everything and watch my mash/sparge pH/temp. To be honest I don't care which one of them fixes the problem as long as it's gone...unless it comes back, but at least if it does I will have narrowed it down to one of two things.

Seems like most people use 2 tablespoons bleach/5 gallons of cold water. Does that sound right?

 

[MerlinWerks]

I believe I've seen posts by Martin and others that sparge water alkalinity is more important than pH and if you are sparging with RO you should not need to add any acid to lower pH because the alkalinity should be extremely low already...

FWIW, I've been having a similar problem with a bit of sourness in the finish and I believe I've narrowed it down to over carbonation. As an experiment, try setting your reg 3-4 psi lower than you have been for a week or two.

 

[joshesmusica]

I think you're right. As much as I hate to change more than one thing at a time, I'm going to clean the hell out of everything and watch my mash/sparge pH/temp. To be honest I don't care which one of them fixes the problem as long as it's gone...unless it comes back, but at least if it does I will have narrowed it down to one of two things.

Seems like most people use 2 tablespoons bleach/5 gallons of cold water. Does that sound right?

I hate to burst your bubble, but if you fix those two things, and the problem comes back, then it's not either of those issues.

I honestly don't know how much bleach to use, even though I just bleach bombed a bucket of mine. I just added some, and then filled it up, and thought, if the smell isn't pretty overwhelming after it's filled, then I'll add more. Though mine wasn't a bacteria, mine was wild yeast. I then soaked it for a couple of days in pbw, after I let it air dry, and smelled it to see if it still smelled like bleach. I'll probably brew a batch on monday with it to see if it worked.

 

[ncbrewer]

A Beersmith newsletter said to use 1 Tbsp per gallon for a soak time of 15 minutes for sanitizing. And don't plastics soaking too long or the bleach will soak in.

 

[chudsonvt]

Do you monitor the SG of your runnings? I used to fly sparge until I had my target volume. I had a couple batches come out very astringent. Now I monitor my runnings as I lauter to be sure that I don't go below 1.008 at the end (refractometer for fast measurement). If target volume isn't hit, either brew a smaller batch or top off with more water int he kettle. As the gravity gets too low, the pH is too high and you start pulling in more tannin from the husks. This should not be a problem with a single batch sparge but since you are doing a second sparge, you likely are having a high pH. Maybe your pumpkin did not have the problem because of your water to grain ratio being lower?

 

[Renaveg]

Good point, I don't measure my final runnings, but I should and I had wondered if that might be the problem. i will monitor on my next brew.

 

[Renaveg]

Ok, so in cleaning all of my equipment today I decided to take apart the ball valve from my brew kettle and this is what I found. Pretty disgusting and is most likely the culprit. I've always cleaned it with a brush, but obviously it was not getting everything. I also would've thought that since it's on the brew kettle it would've got hot enough to kill any bacteria, but maybe being on the outside of the kettle it wasn't getting hot enough. I'm going to clean the hell out of this one, but I'll also be ordering a 3-piece for easier cleaning moving forward.

 

[Renaveg]

I've done 2 brews since I swapped out the ball valve and I don't detect any off-flavors at all so it was definitely the ball valve. Thank you to everyone that responded! I'm finally excited to brew again, already looking forward to the next one!

Thanks again,
Dave