Need your help eliminating this off-flavor!

First of all, I’m sorry for the long post…especially with this being my first one on this forum. However, I’m having a serious problem with what I can best describe as a raw grainy flavor in my lighter AG beers. Right now I have done just about everything I can possibly think of to eliminate this off-flavor, so I’m enlisting the expertise of this forum. Here’s some background on my problem, process, and troubleshooting.

Currently I use a full volume BIAB method (although I remember having this same flavor dominant in previous lighter AG beers where I have batched sparged). I mash in the entire volume of water, normally in the mid to low 150’s for an hour. I then raise the temp to 168-170 for 10 minutes for a mashout. After this time, I pull the bag out of the kettle and sit it in a colander to drain back into the kettle while bringing the wort up to a boil. I do not squeeze the bag at all. Once I reach a boil, I remove the bag and boil for 60 minutes. At the end of the boil, I use my IC to chill to 65 degrees before pitching. I then ferment around 65-67 degrees and will always leave it in the primary for at least 3 weeks. After that, I normally will rack to keg, put it on gas for about a week, and then tap it.

Now, I only pick up this flavor in all of my lighter AG beers (ie, Pale Ales, Blondes, etc). I have recently brewed an AG Mild and American brown and an extract IPA and Cal Common. I had no hint of the graininess in any of those. In my beers with this off-flavor, it is apparent enough that it really dominates the taste of the beer and it doesn’t really subside over time. Last night I just tried a pale ale I brewed 3 months ago. The grainy flavor was still quite present.

To try and eliminate this problem, I have done the following:

  1. I used a voile bag which has a much finder weave than the previous bag that I was using. This should eliminate any grain escaping the bag and ending up in the boil.

  2. I sent a water sample off to Ward, which came back with the following:

pH 7.6
Total Dissolved Solids (TDS) Est 82
Electrical Conductivity, mmho/cm 0.14
Cations / Anions, me/L 0.7 / 0.7

ppm
Sodium, Na 4
Potassium, K 2
Calcium, Ca 7
Magnesium, Mg 1
Total Hardness, CaCO3 22
Nitrate, NO3-N 0.1 (SAFE)
Sulfate, SO4-S 4
Chloride, Cl 6
Carbonate, CO3 < 1
Bicarbonate, HCO3 15
Total Alkalinity, CaCO3 13

Per these results, I used 1 gram of Calcium Chloride per gallon of water. Since I started with 8.5 gallons of water, I used 8.5 grams. I also added 2% acidulated malt to my grain bill.

  1. After flameout, I leave the lid off of the kettle until reaching below 160 degrees.

By doing these 3 things, I hoped to have eliminated any off flavors due to 1. Tannin Extraction from grain in the boil, 2. out of whack pH or low calcium, 3. DMS caused by lid on the kettle while wort is still near boiling temps.

With all of these changes in place, I recently brewed a 4% Blonde. I was really optimistic, but after the first sample I could tell that the problem was not fixed. I just racked to keg last night after 3 weeks in the primary and took another sample. The flavor was still there and had not subsided in the least.

I’m kind of at a loss as to what to do next. Should I double bag the mash in case too many grain bits are still getting through? Or invest in a pump and do some sort of recirculation through the grain bed? Not sure if this will fix it either since I used to batch sparge and vorlouf and had the problem even then. Plus, wouldn’t we hear of more BIAB brewers having this same problem? Should I try 90 minute boils?

Looking forward to your input and any suggestions that you all can provide!

The first thing that comes to mind with a grainy (tannin) flavor is mash pH. Did you measure your mash pH, it should be in the 5.2-5.7 range. Also, maintaining a mash pH of 6 or less during the sparge is ideal as it will mitigate tannin extraction from the grain.

The second consideration is your crush, you want to crush fine while maintaining the integrity of the husks as this is ideal.

Previously I was using 5.2 in the mash until a lot of people mentioned that it really doesn’t work all that well. I then changed to filtering my water and adding the calcium and acidulated malt that I mentioned above. I’ve read that the ph test strips don’t work all that well, and I just haven’t wanted to spend the $$ on a pH meter, so I haven’t taken any readings to see where exactly I am. Maybe I just need to break down and buy one.

As for the crush, I forgot to mention this in my original post. I used to use a corona style mill, and too thought it was due to husk shredding by the mill. Since then, I have switched to a crankandstein. I have it set on the default gap and run it on a very low RPM. The crush looks pretty good to me, with minimal flour.

Agreed.  That’s the first thing that popped out to me also.  Especially considering that the problem occurs on the lightest of the brews.  In general, the darker the grain, the further down it is capable of pushing the pH.  The grist for the lighter brews, having no/little dark grains, is only capable of lowering the pH slightly.  The problem is also exacerbated by the fact that you’re mashing with the full volume of water.  You’re asking your grains to lower the pH of a much larger volume of water than if you were using the more normal 1-2 qts/lb.

First thing is to measure your mash pH.  The ColorPHast strips give a pretty reasonable measurement if you don’t want to spring for a pH meter.  If you verify that your mash pH is too high, there’s a couple things you can try.  One would be adding acid to the mash until the pH is correct.  The other might be to mash with a lower ratio of water to grain - you could later sparge or just top off to get your final boil volume.

Thanks guys. The next thing I’ll do is check mash pH.  I added 2% acidulated malt to hopefully get me in the range, I suppose it might have helped but not enough.

You might try mashing with 1.5 quarts per pound or so instead of putting your grains in the full water kettle volume.  You can add more water after removing the grain.
Are you using domestic malts or imported?  2-row or 6-row?

I’ve used both CMC 2-row as well as Tom Fawcett Marris Otter. The thing is though, when I batch sparged I would generally do it in 1.25 - 1.5 qt/lb and would still pick up on that grainy flavor.

Another vote for pH.  If the OP is mashing with the full volume of water and not adjusting pH, it’s likely that the grain isn’t bringing it down far enough for light beers.  use the correct amount of water and check your pH, as mentioned.

Denny, I’m actually using the Aussie BIAB method which calls for a full volume mash and no sparge. Others have had much success with this method with no obvious detriment to the final product. In fact, I haven’t noticed any difference in my beers since going with this method. The grainy flavor that I’m struggling with was present even when I was batch sparging in a chest cooler. Doing that method, I would generally always calculate my mash at 1.25 qt/lb.

So now the general consensus seems to be that the issue is with pH, I’ve been researching pH meters. It seems that all within my price range (~$100 or so) do not work at mash temps. You need to draw a sample and cool it before getting an accurate reading. So, my question is how soon after mashing in do I need to make adjustments to my pH? By the time I draw the sample, let it cool, and perform the measurement, will the damage already be done?

Also, before going out and spending money on a pH meter, could I maybe do a batch by building up a water profile using Distilled / RO water? Is there a baseline “water recipe” that I could use that we’d know would put the water in the correct pH range? If the batch comes out without the grainy flavor, then presumably I’d know the issue is with my water???

What does your grain crush look like? Too much damage to the husks can cause this.

I’d look in this area before I looked at ph meters, RO water build ups, etc.

Here’s a look at the crush I’m getting on the default settings on my crankandstein.

That looks fine to me.  My crush is finer than that.

Since you’ve already got the report on your water from Ward Labs, before you do the RO/distilled thing, why don’t you try Martin’s water spreadsheet and see what it tells you…

http://www.homebrewersassociation.org/forum/index.php?topic=6016.msg72038#msg72038

Hard to see from the picture, but while it looks fine, some of the husks seen to be shredded. What kind of a mill are you using?

What’s the problem with shredded husks?

Lighter ales always taste kind of grainy to me.  Are we sure it is actually tannins that are the problem as opposed to the flavor of grains?

I don’t think that’s been established.

I’m using a crankandstein 2A on the default gap setting.

This is a pronounced grainy flavor. I have never tasted it in any commercial Pale Ale’s or Blonde’s that I’ve had. I suppose that it could be the grain, but I’ve experienced the same issue with both 2-row (now that I look at it it’s actually Pale malt) and MO from 2 different maltsters, so I’m not sure if that’s it or not. I did just buy 3 new sacks of CMC 2-row, I could open one of those up on my next batch to determine if it’s the malt.

It doesn’t necessarily mean there is anything wrong with the malt, it’s just that some styles taste grainy to me.  It could also still be a little bit of tannins due to the pH, it’s hard to say without tasting it.

I think I like the the Bru’n water suggestion, people have had luck with it nailing the pH.  So you can calculate what the pH would be with what you’ve been doing, and figure out how to adjust it for your next batch.  That would be my first step I think.