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:
Total Dissolved Solids (TDS) Est 82
Electrical Conductivity, mmho/cm 0.14
Cations / Anions, me/L 0.7 / 0.7
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.
3. 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!