Mash Thickness and Efficiency

[sibelman]

everyone

Nope. I have no idea what everyone does. Just that it's an option.

Frankly, given that you're not getting much of anything from continued sparging past 1.010 - 1.008, it's almost the same as adding water to the kettle.

 

[doug293cz]

@mabrungard had this to say on the topic:

Plus the tannins and silicates that you leach from the grain. Oversparging can be quite damaging to your beer. While the lore is that keeping sparging water pH lower than 6 and cooler than 170F will keep you from leaching those components, I find that the most important thing is to avoid reducing the wort gravity within the mash bed to less than about 3 or 4 brix. There is a nice figure in Malting and Brewing Science showing the tendency to extract tannins is directly proportional to the reduction in runoff wort gravity. Don't do it!

Monitor your runoff gravity very closely and avoid filling the tun with too much sparging water. If you need to top of the pre-boil kettle volume, add the sparging water directly to the kettle and don't run it through the mash bed. That technique has corrected my one-time tannin problems.

Brew on

 

[mashdar]

@mabrungard had this to say on the topic:



Brew on

That's an interesting quote. If Martin says that, who am I do disagree? (Nobody, that's who!)

I do find it curious on a chemical level.

 

[doug293cz]

That's an interesting quote. If Martin says that, who am I do disagree? (Nobody, that's who!)

I do find it curious on a chemical level.

I will also accept Martin's info on tannin & silicate extraction over anything I may have said.

Brew on

 

[day_trippr]

I can't remember where I picked up these three guidelines, but they are:

- sparge with 170°F liquor
- keep end-of-runnings pH below 5.6
- keep end-of-runnings SG above 1.010

specifically to avoid drawing tannins and silicates into the kettle...

Cheers!

 

[MaxStout]

For those fellow BIAB brewers who might be tuning in...

I think there's a similar problem that can crop up with pour-over or dunk sparging. In winter I would brew indoors, in a smaller kettle on my stove top. I'd mash with 5 or 6 gallons of strike water, hoist out the grain bag and pour over the remaining 2 or 3 gallons to sparge. I noticed some of those beers being astringent and I realized the sparge may have been the culprit. (I don't do dunk sparging, but think it could be susceptible to the same problem if the dunk wort gravity goes too low.)

This was before I bought a pH meter, but even if I had one then, I believe that the sparge runnings would have inconsistent pH and be difficult to accurately measure overall. In pouring a couple gallons over a mass of grain, I don't think it permeates evenly. This is my wild-ass theory: I think it's possible that some of that grain will have more sparge water running through it--more through the outer regions and less through the center. Hence, over sparging in some portions of the grain. Enough to still release some tannins.

I changed this a few years ago--no more pourovers. When I need to set aside some water for post-mash, I just pour it into the kettle after the grains have been removed, then ramp up to a boil. My beers since then have been free of the astringency problem.

 

[Uke733]

@mabrungard had this to say on the topic:



Brew on

I suppose just batch sparging is one way to avoid it all.

Repeating in my head "adding water isn't cheating, adding water isn't cheating"...... repeat!

 

[doug293cz]

I suppose just batch sparging is one way to avoid it all.

Repeating in my head "adding water isn't cheating, adding water isn't cheating"...... repeat!

Single batch sparging will usually avoid over-sparging issues, but multiple batch sparges can over-sparge low OG beers (less than about 1.045.)

For extremely low OG beers (less than about 1.030 OG) a single batch sparge can get into over-sparge territory.

You can use my batch sparge simulator for your specific conditions to predict what your final runnings gravity should be. To use the spreadsheet, download as either an Excel or LibreOffice spreadsheet, and use it locally on your computer.

Brew on

 

[Uke733]

Single batch sparging will usually avoid over-sparging issues, but multiple batch sparges can over-sparge low OG beers (less than about 1.045.)

For extremely low OG beers (less than about 1.030 OG) a single batch sparge can get into over-sparge territory.

You can use my batch sparge simulator for your specific conditions to predict what your final runnings gravity should be. To use the spreadsheet, download as either an Excel or LibreOffice spreadsheet, and use it locally on your computer.

Brew on

Ummm, thanks, I think.

Your simulator has left me feeling a little less intelligent....

Why on earth am I sparging on low alcohol beers? 80%+mash efficiency with AIO no sparge is more then enough for this guy.

Bigger beers won't fit in my kettles as I usually do 12 gallon batches, but lower SG beers would.