High Eff. with an odd taste

[wmilas]

So recently I upgraded my system to an all electric Blichmann W/ autosparge. Coils int he HLT, and the BK with a HERMS. After this upgrade my efficiency to the BK is over 90% regularly. The smaller the beer, the higher the efficiency (for obvious reasons). I've only been dropping below 90% on RIS type and larger beers. I have 10+ brews on the new system under my belt

Anyways, I'm getting an off flavor. I want to say its tannin type, but I'm not getting the pucker in my mouth. The best way to describe it is that of an aftertaste of grain husk. I'm fearing its a precursor to tannin extraction but I'm not sure. None of my brew buddies taste it, but I'm POSITIVE its there. I can taste it more pronounced the smaller the grain bill/ABV so I'm pretty sure its grain husk extraction.

I've done my homework on sparge Temp, PH, and OG of sparge. I'm stopping at what I think is the limit but I still taste it.

I'll post my last 2 brews below:

First Brew (a Porter)

8lbs 14.7 oz Marris otter
6.6 oz Crystal 60
6.6 Oz Chocolate
6.6 Oz Special B
3.3 Oz Black Pat.
1.52 oz centenial @ 60
.52 Oz Willamette @15
.41 Oz Willamette @ 5
WLP 007 (1.5 L starter flask)

Ro/DI water adjusted to:
54.2 ppm Calcium
0 Mag
12.2 Sodium
44.2 sulfate
33.5 Chloride
108 Bicarb

1 gal strike per 3 lbs grain
Mash 154F
Fly sparge at 168F for an hour, 6.97 gal into BK

Last runnings were SG 1.007, PH 5.7 with a PH digital temp adjusted reader
5.8 Gal after boil
5.5 gal into fermenter
SG 1.0615
92.95% Eff.
FG 1.016
ABV 6.14%, 73% attenuation.


Second Brew (A English Mild)

3lbs 13.1 Oz Maris Otter
7.6 Oz Caramunich
6.1 Oz Chocolate
3.8 Oz Caramel 10
3.8 Oz White Wheat
1.5 Oz Carafa III
.4 Oz Amarillo @60
Wyeast 1728 1.5L starter

Ro/DI adjusted to:
55 ppm Calcium
0 Mag
12 Sodium
66 Sulfate
51 chloride
90 Bicarb

1 gal strike per 3 lbs grain
Mash 148F
Fly sparge at 168F for an hour, 6.97 gal into BK

Last runnings were SG 1.004, PH 5.9 with a PH digital temp adjusted reader
5.8 Gal after boil
5.5 gal into fermenter
SG 1.034
99.63% Eff.
FG 1.008
ABV 3.27%, 71% attenuation.


Granted I went through the cutoff for tannin extraction on the English Mild. If I tasted tannins I'd get it. I just taste husk though. In fact I taste MORE husk in the Porter than the mild, even though I should taste it more in the mild. Its hidden upfront in the porter but its strong on the palate at the finish.

I use fresh malt, I grind it myself with a Barley Crusher at .33 10 mins before Dough in.

I'm kinda confused. I just made a monster RIS this Saturday and no where near came close to the tannin extraction limit with a ph of 5.3 and 1.025 last runnings. I have to wait a month or so before I can sample it for grain husk taste.

So am I tasting tannins? If I am, what do i do? I can open up the mill and not crush as fine, or I can use more grain, but I'm going to blow my calculations and end up too high. I'd have to add water to the BK to lower the SG.

I know commercial breweries are over 96% all the time. How do they handle the PH in the mash kettle at end of sparge at high efficiencies?

Help

Thanks!

 

[Magnus314]

I was getting the same kind of off flavor doing BIAB and getting 88+% efficiency.

Thinking it might be tannins even though it didn't "pu ker", I switched to a cold sparge and it went away.

Since then, to save time to boiling, I do a warm sparge ~150* (instead of hot sparge ~170*) and I do not get that off flavor any more.

No idea what it's called, but I know what's causing it.

 

[masaba]

I was listening to the Jamil Show a few days ago and he said that he shoots for 70% efficiency. He thinks that if you start to go higher you could start extracting some undesirables from the grains, like tanins and other astringent flavors.

Also, how do you know for sure that commercial breweries are getting over 90% efficiency? I have seen that posted on HBT several times, but have never seen any evidence for it.

 

[serum]

I've got this exact same problem with my 2 vessel system and it definitely reared its ugly head when my efficiency started getting better.

After getting some advice I'm skipping mash out, which I was doing by infusing with boiling water and going stright to fly sparge straight away although I'm going to try a batch sparge too. I did a cooler sparge on my last brew so hopefully that will help as well.

 

[wmilas]

I know that commercials get greater than 90% from a variety of sources. First there have been threads here where some Craft brewers have posted than when efficiency falls below 95% they start looking into what is "wrong" with the process. Second when I was googling tannin extraction you can find threads on different sites were commercials talk about efficiency. Third, if you think about it, one of their largest costs is grain. They need to extract as much as possible to turn a profit.

I've heard the Jamil show where says this. It doesn't make sense though. I mean it makes sense to remove the possibility of tannin extraction but you are leaving behind so much sugar. It seems wasteful. I did not build my system for maximum possible efficiency, its just a side effect of a all electric /HERMS system. I built the system so I could brew inside in the cold Chicago winters

I honestly don't think I could lower my efficiency to 70% now unless I opened my crush up so high that I got mostly whole kenerls, or if I just did one large single batch sparge.

That doesn't make sense though. Germans have been fly sparging forever and they don't have this problem. I'm thinking I need to acidify the mash during the sparge or something. Maybe acidify the sparge water? Perhaps that and lowering the sparge temp down to 150F or so might help?

I'm thinking of adding acetic acid to the sparge water. I could add it directly to the mash when fly sparging starts, or perhaps half way through but it might just be sparged out. If I put it in the sparge water that might work.... Anyone know?

I have stopped mash out and I did notice a lessening in husk flavor. So temp definitely has something to do with it.

 

[aangel]

Acidifying the sparge water's been mentioned before as a good thing to do. From Kal at http://www.theelectricbrewery.com/brew-day-step-by-step?page=7

"Mash-out is a good time to acidify the sparge water (if required). To avoid excess tannin extraction from the grain husks, we want the sparge water pH to be below 6.0 (when measured at mash temperature), preferably in the 5.6 to 5.8 range. "

 

[wmilas]

aangel: Good find. I never read through his step by step process. He also heats sparge to 158 then turns it off letting it naturally drop during sparge.

I'm going to try both of these!

Thanks!