Mash Thickness Confusion

[ILikeBrew]

First-time poster.

I am confused as to the effect of thinner mashes on wort. My brother and I have brewed 3 AG batches using single infusion mash with a double batch sparge. We have come out to 75% efficiency each time. Call me greedy, but I am shooting to get 80%. I have read several posts on here and other sites about tips for increasing efficiency with AG batch sparge brewing and the only thing I think I might change is my mash thickness. I have read on Kaiser's website that thinner mashes increase efficiency without affecting the fermentability of the wort. I have read other sites that confirm the increase in efficiency, but warn that thinner mashes create more fermentable wort due to increased diastatic activity.

My question is, if I use a thinner mash, should I adjust my mash temperature to compensate for the increased diastatic activity?

 

[chode720]

Personally, I have noticed that with thicker mashes, around 1.25 instead of closer to 1.5, my efficiency has dropped from 75% to 70%. However, i have not noticed any differences in the fermentability of the wort.

The best way to run this experiment is to brew a beer with the exact same mash temperature you used the last time, but increase the water to make it thinner. Then when its done fermenting, compare the OG of that beer to the beer you brewed with the thicker mash. Then you will know for sure if it makes a difference in your system

Also, Welcome to HBT!

Here is some info from www.howtobrew.com/section3/chapter14-6.html

The grist/water ratio is another factor influencing the performance of the mash. A thinner mash of >2 quarts of water per pound of grain dilutes the relative concentration of the enzymes, slowing the conversion, but ultimately leads to a more fermentable mash because the enzymes are not inhibited by a high concentration of sugars. A stiff mash of <1.25 quarts of water per pound is better for protein breakdown, and results in a faster overall starch conversion, but the resultant sugars are less fermentable and will result in a sweeter, maltier beer. A thicker mash is more gentle to the enzymes because of the lower heat capacity of grain compared to water. A thick mash is better for multirest mashes because the enzymes are not denatured as quickly by a rise in temperature.

A compromise of all factors yields the standard mash conditions for most homebrewers: a mash ratio of about 1.5 quarts of water per pound grain, pH of 5.3, temperature of 150-155°F and a time of about one hour. These conditions yield a wort with a nice maltiness and good fermentability.

 

[Bobby_M]

Actually, the best way to figure out if a thinner mash would help is to take a mash efficiency sample and see if you're 100% converted. If you are, thinning out should actually degrade your lauter efficiency. Empirically, I lost a good 10% going from 1.25 to 1.6.

 

[mkling]

My personal recommendation is to be happy with 75% efficiency and spring for the extra 1/2 lb of grain if you want your wort gravity to be a bit higher. Lots of really serious, much more award winner brewers than me have suggested that you run risks of many more bad things than you might get benefits of good things by shooting for efficiency higher than 75% including astringency. Grain is cheap. For most beers the yield difference between 75% & 80% efficiency is only adding 1/2 a pound of base malt to your 75% mash -- that's 60 or so cents. Saving that isn't worth the risk of an astringent batch of beer.

 

[Denny]

Actually, the best way to figure out if a thinner mash would help is to take a mash efficiency sample and see if you're 100% converted. If you are, thinning out should actually degrade your lauter efficiency. Empirically, I lost a good 10% going from 1.25 to 1.6.

Very interesting, Bobby. I've either seen no difference or a slight gain, but I haven't really been tracking it closely. I think maybe I'll start doing that. What size batches do you typically make, and did you see any difference in higher mash ratios based on the OG of the beer?

 

[Bobby_M]

Now that I think of it, my 10% loss can be half correlated to additional deadspace. I should say that I lost 10% going from a cooler with a braid to a keg with a full false bottom. I'm forced to mash thinner to recirculate and I know I leave some wort after a "full" draining due to the nature of the siphon tube. I don't know what portion of that 10% is attributable to which. IOW, my data sucks. I would have to mash thinner in a cooler to test it.

 

[Denny]

Thanks for the explanation!

 

[ILikeBrew]

Alright, did more reading. Seems to be a lot of different opinions. I am going to try a thinner mash next time because I just used beersmith's setting in my calculation which is 1.25q/lb. I think I'll start by moving it to 1.5 and see if I see an increase in efficiency.

Questions: Do I just now sparge with less water (double batch sparge equal amounts) or do I sparge with the same amount of water and boil off the extra? Also, if I move up to like 2q/lb., it would really decrease the amount of water to sparge with. Will this create a problem? Currently I use my first batch sparge at boiling to bring the temp up to 168ish. How would I do this with smaller batch sparges?

 

[Q2XL]

I have been going with 1.25qts for my first 17 beers and have been getting anywhere from 63% to 73%. Today I raised it up to 1.50qts and I got 79%. So, I will try again next time with 1.5qts and see what happens.

 

[homebrewer_99]

Question: I know when I mash the grain (nut, whatever) is all mush after sparging.

Does the degree of crush also affect efficiency based upon the smaller grain pieces having more surface to water contact?

 

[GilaMinumBeer]

Yes until the point is reached that the girst to flour ratio is so high you get nothing but a giant dough ball.

 

[Denny]

Alright, did more reading. Seems to be a lot of different opinions. I am going to try a thinner mash next time because I just used beersmith's setting in my calculation which is 1.25q/lb. I think I'll start by moving it to 1.5 and see if I see an increase in efficiency.

Questions: Do I just now sparge with less water (double batch sparge equal amounts) or do I sparge with the same amount of water and boil off the extra? Also, if I move up to like 2q/lb., it would really decrease the amount of water to sparge with. Will this create a problem? Currently I use my first batch sparge at boiling to bring the temp up to 168ish. How would I do this with smaller batch sparges?

Try just doing a single batch sparge. That's what I do 99.9% of the time and I average 83% efficiency. Also, it's not a big deal to hit 168 for sparging. If you can, great. If you can't, no problem.

 

[Denny]

Question: I know when I mash the grain (nut, whatever) is all mush after sparging.

Does the degree of crush also affect efficiency based upon the smaller grain pieces having more surface to water contact?

Yes, it does.

 

[The Pol]

I love me some thin mashing. No affects on my FGs yet.

Mash as thin as you must to get nearly 100% conversion eff. and stop, anything more will yield no gain in conversion eff. (obviously) and will only steal from your lauter eff. (less sparge water)

 

[dirt55]

Odd that Mkling's reply has not been commented on.

It seems that it's very popular among pro am brewers to prefer 70% or 75% because if you over sparge/get a bigger eff then you will extract out the bad with the good and your product will suffer in taste. I'm no AG pro, just passing on what I've read/heard from people in the know.

 

[The Pol]

Odd that Mkling's reply has not been commented on.

It seems that it's very popular among pro am brewers to prefer 70% or 75% because if you over sparge/get a bigger eff then you will extract out the bad with the good and your product will suffer in taste. I'm no AG pro, just passing on what I've read/heard from people in the know.

But what is "over sparging"? I mash at 2qt/lb, so my sparge volume is about 3.5 gallons. In order to sparge less, Id have to mash even thinner. My eff. is exactly 82% as it stands. How would I go about sparging less, without mashing REALLY thin.

 

[dirt55]

I think I worded that wrong.

"Don't get overly concerned over getting an efficiency above 70-75%" is the main thing I've heard. Some people may attempt to increase their eff by "over sparging" such as having their runoff being as clear/clean as tap water, or having the runoff be below 1.010 roughly. But there are other ways to bump your eff besides sparging it dry as can be.

not sure if i'm making sense...at the end of my 12hr shift..sorry

 

[The Pol]

You make complete sense.

I moved to the thinner mash to help with the HERMS recirc. and to improve my conversion eff. In doing so, I also realized that I had reduced my sparge length and volume, which would produce a lower PH wort and create less of a chance of extracting undesireables from my mash.

I like to think that I have higher quality wort now than I did with a thick mash and copious sparging, and I increased my conv. eff. to near 100%.

Good points about eff. though. It isnt something to be chased if the persuit causes you to compromise the quality of the product.

 

[ILikeBrew]

The reason I didn't reply to Mkling's message is that once again I've heard differing opinions. And to be honest I think I'm like any homebrewer, I know 5% doesn't make much difference... I just always want to improve the process, you know?

I think "over-sparging" doesn't really come in to play with batch sparging though, right?

I haven't been taking a FW measure to determine my conversion efficiency. I will try this next time to isolate which process could be improved (mash or sparge).

Thanks Denny, I'll try the thinner mash with a single batch sparge. I had always read double or even triple batch sparging (equal proportions) produced better sparge efficiency, but it seems like it is working for you.

I'll be aware of the possibility of extracting tannins, etc. If I taste it in the beer, I think I'll just make the mash a little thicker the next batch.

 

[homebrewer_99]

The reason I didn't reply to Mkling's message is that once again I've heard differing opinions. And to be honest I think I'm like any homebrewer, I know 5% doesn't make much difference... I just always want to improve the process, you know?

I think "over-sparging" doesn't really come in to play with batch sparging though, right?

I haven't been taking a FW measure to determine my conversion efficiency. I will try this next time to isolate which process could be improved (mash or sparge).

Thanks Denny, I'll try the thinner mash with a single batch sparge. I had always read double or even triple batch sparging (equal proportions) produced better sparge efficiency, but it seems like it is working for you.

I'll be aware of the possibility of extracting tannins, etc. If I taste it in the beer, I think I'll just make the mash a little thicker the next batch.

Actually, tannins come into play when you OVER sparge. From what I've read, when fly sparging you sparge (for clarity) until the gravity goes down to 1.008 then you stop. After that you'll start to get tannins because most of the sugar is gone.

I do batch sparging, but I limit it to 1 gal at most.

 

[Denny]

Actually, tannins come into play when you OVER sparge. From what I've read, when fly sparging you sparge (for clarity) until the gravity goes down to 1.008 then you stop. After that you'll start to get tannins because most of the sugar is gone.

It really doesn't have anything to do with sugar. It's because the buffering power of the grains has been "used up".

 

[Picobrew]

I do batch sparging, but I limit it to 1 gal at most.

One gallon? That's a lot of batches! I usually do one batch sparge that ends up being nearly 5 gallons. Am I crazy?

 

[Denny]

One gallon? That's a lot of batches! I usually do one batch sparge that ends up being nearly 5 gallons. Am I crazy?

No, you're not....a 1 gal. batch sparge is crazy!

 

[homebrewer_99]

HAHA!! What I mean is, when I batch sparge I only use 1 gallon of sparge water.

 

[Picobrew]

HAHA!! What I mean is, when I batch sparge I only use 1 gallon of sparge water.

I still don't get it!!!

 

[The Pol]

I still don't get it!!!

He mashes thin, and only sparges with ONE gallon of water, it is easy.

 

[Picobrew]

He mashes thin, and only sparges with ONE gallon of water, it is easy.

For me to require only a 4 qt sparge, I would have to mash at 3.7qts/Lb . I have never heard of mashing that thin.

I've wanted to play around with all this - what is the cheapest/easiest way to test for conversion?

 

[The Pol]

For me to require only a 4 qt sparge, I would have to mash at 3.7qts/Lb . I have never heard of mashing that thin.

I've wanted to play around with all this - what is the cheapest/easiest way to test for conversion?

Take a gravity reading from the mash, and use Kai's chart.

3.7 is thin, but it is no different than what is done in BIAB.

 

[KayaBrew]

This has been a really helpful topic. I just mashed in my oatmeal stout at 1.46qt/lb. to compensate for the flaked oats and rice hulls. I'll still do a double batch sparge, but with less than 2 gallons each. My total strike volume was 4.93 gallons for 13 lbs of grist.

 

[Denny]

I'll still do a double batch sparge, but with less than 2 gallons each.

Why the heck wouldn't you do it all in one sparge?