Mash-out, Denaturing and Sparging

But it's also temperature related. When you have a high mash pH and a high temperature, you'll extract more tannins than you will with the same high pH but a lower temperature. Lack of tannins from decoction doesn't disprove that, because the pH of a decoction is not particularly high.

 

Your PS is a good caveat to my earlier comment about pH and tannins. I was thinking about it only from the batch sparger perspective, where you do not appreciably and continually dilute the acidity in the mash to the point of tannin extraction. Adjusting the pH of the sparge water, as Bru'NWater and other water chem programs suggest, would also circumvent the tannin extraction issue.

 

That is what I do when I fly sparge. My preferred tool is MpH.

Cheers!

 

You can pull part of the mash and decoct, then add the near boiling part back in if you run out of room.

 

I need to run another side-by-side controlled experiment one of these days to figure out if decoction actually helps the flavor at all. A lot (most?) people are saying these days that it doesn't actually do much for taste. However it does improve your efficiency by a few points, and if done in the traditional manner, extends the amount of time on brew day substantially. I still decoct once in a while for fun but not sure if it really does much for flavor. When I do decoct, I go as fast as possible -- all my rests are only for like 10 minutes so I can still get done in about the same time as a normal batch.

 

I have heard Kai Troester make similar remarks in podcast discussions.

Cheers!

 

Rise from your grave...

My decoction vs. not experiment is in process, results forthcoming. I have in fact brewed two marzens with identical recipe, ingredients, and malt percentages, but one decocted and sparged for an efficiency of 81% and OG=1.049, and the other single-infused and not sparged with efficiency of 64% and OG=1.053. So yeah, the OGs were a little off, but I really had to guess what my efficiency would be on the no-spage batch because I always sparge. And yes, this is actually a double-variable experiment, not just decoction vs. single infusion, but also high efficiency vs. low efficiency and/or sparge vs. no-sparge. What can I say... I'm trying to kill two or three birds with one stone. I just bottled last night and now have a preference for one over the other. We'll have to wait a few weeks to see if my opinion changes with carbonation and serving temperatures.

Many many unexpected results though.....
The two batches look and taste a bit different..... one with a touch more haze, one with diacetyl and the other not. I'm hoping the diacetyl disappears with a few weeks of age as has been my experience in the past. One I feel has a much richer malt flavor than the other. Final gravities were also quite different, 3 points from one another. The same yeast and quantities were used, so this was quite a surprise to me. Feel free to take guesses as to what's what. The big reveals will happen later, probably in a new thread as opposed to this hijack.

Cheers.

 

I am presuming that you will conduct a blind triangle test here?

Did you conduct a diacetyl rest for both fermentations?

Cheers!

 

Well, I might not be blind anymore perhaps, but yes. I plan to run semi-blind triangles on myself and also to use my homebrew club as piggies on this if they're interested.

Both fermenters sat at 65 F for about 5 or 6 days. Funny how the diacetyl always seems to appear AFTER the d rest. It tasted clean prior to the rest. :shrug: