thinner mash or more (batch) sparge water?

[brewzombie]

WRT mash efficiency and batch sparging, is it better to have a thinner mash (eg 1.5 qt/lb) and less sparge water or a thicker mash (eg 1 qt/lb) and extra sparge water? It makes sense to me that I'd be better off with the extra sparge water to better rinse the grains and dilute any dead volumes in the mash tun. I'm aiming for a 7 gal pre-boil volume and am wondering whether to dilute the mash to get a somewhat equivalent volume for the first runnings and sparge (as I believe Denny recommended at one point) or to thicken the mash and rinse more.

Thoughts?

 

[BBL_Brewer]

I get pretty good efficiency with equal runoffs from the lauter and sparge. For a 5 gallon batch that usually puts me at about 1.5 qts/lb mash ratio.

 

[brewzombie]

I get pretty good efficiency with equal runoffs from the lauter and sparge. For a 5 gallon batch that usually puts me at about 1.5 qts/lb mash ratio.

Thanks. Any particular reason for aiming for equal runoffs?

 

[MrTheKing]

Try both and see what works best for your system.

 

[JJL]

I typically use between 1.25 and 1.8 qts/lb. My reasoning is simplicity. I almost always use 5 gals of mash water. It makes all of my calculations easier. It simplifies my water adjustments. Then I just adjust my sparge water accordingly. Usually, I end up with a little less sparge water (usually 3-4 gals) than mash water. My effeciency is always in the low 70's. The only time I vary from this is when I make a really low or high gravity beer. This works for me for any beer between 1.045 and 1.085 OG. But I only know this because I've tried it and I know it works on my equipment.

But, you're going to have to try things out fo yourself. This is one of the great debates in homebrewing. How much water is too much water in your mash? The only thing most people seem to agree on is that if you get down below 1qt/lb, your efficiency will probably start to suffer.

 

[Bobby_M]

Thanks. Any particular reason for aiming for equal runoffs?

All else being equal, the closer the volumes of the runoff are to each other, the more efficient. The effect is minimal, but if you're picking volumes anyway, no reason to make them too asymmetric.

Here's how to do it;
Strike water volume = (Preboil volume desired/2) + anticipated grain absorption losses as (pounds of grain x .1)

Example use:
(7 gallons/2) + (14 x .1)
(3.5) + 1.4)
4.9 gallons of strike which should give you 3.5g of first runnings.

Now you just sparge with half of your desired preboil volume or 3.5 gallons.

 

[brewzombie]

All else being equal, the closer the volumes of the runoff are to each other, the more efficient. The effect is minimal, but if you're picking volumes anyway, no reason to make them too asymmetric.

Thanks! It seems so counter-intuitive that rinsing more would decrease efficiency. It must have to do with a loss of efficiency from the thicker mash, but I wouldn't have thought so as long as I was above the 1 qt/lb. I thought I heard that at a certain thinness (maybe 2 qt/lb?) that efficiency decreases as well. Can anyone comment on this? Maybe the difference is so minimal that it's not worth thinking about. I'm not planning on running the experiment so I'm happy to go with the forum consensus on this one.

 

[hbr2547]

All else being equal, the closer the volumes of the runoff are to each other, the more efficient. The effect is minimal, but if you're picking volumes anyway, no reason to make them too asymmetric.

Here's how to do it;
Strike water volume = (Preboil volume desired/2) + anticipated grain absorption losses as (pounds of grain x .1)

Example use:
(7 gallons/2) + (14 x .1)
(3.5) + 1.4)
4.9 gallons of strike which should give you 3.5g of first runnings.

Now you just sparge with half of your desired preboil volume or 3.5 gallons.

I will need to try this.

 

[hbr2547]

Same with all? Meaning a "big beer" or low abc beer?

 

[billl]

"It seems so counter-intuitive that rinsing more would decrease efficiency. It must have to do with a loss of efficiency from the thicker mash,"

Yep - sugar moves to lower concentration areas. So, if you have a low mash ratio, you have a concentrated wort, and the sugar moves into the water less efficiently. That has to be balanced with the sparge. There more water means a lower concentration and a better sparge. The "best" seems to be to split the difference and shoot for equal runnings from each step.

 

[RmikeVT]

I get pretty consistent efficiency when I brew, between 75% and 78%. I have tried a bunch of different qt/lb ratios with in reason 1.25 up to 2 and my efficiency hasn't really moved.

I think one thing that is being missed here is the mash water to grain ratios impacts the fermentability of the wort. I remember reading something about that in Palmer's How to Brew, so I went searching and dug up the link for everyone. It suggests a thicker mash might lead to more body, and a thinner mash might lead to less body.

http://www.howtobrew.com/section3/chapter14-6.html

 

[RainyDay]

Ive done between 1.3-2.0, but have settled on about 1.6, due to the larger grain bills Ive have and lack of space in the cooler. Im currently getting between 73-78% efficiency, again, based on the grain bill size (lower efficiency on bigger beers). Single sparge, just to get my preboil volume to 6.5 gallons.