Water loss to grain

[NWMushroom]

I am a bit confused. I recently brewed up a brown ale with the following malt bill:

11lb Pale Ale
1lb Munich III
12oz Crystal 60
6oz Chocolate Malt

I had a mash volume of 4 gallons of water. Using the chart in 'Designing Great Beers' I figured I would lose 2.75 gallons to water absorption, leaving me with 1.25 gallons in the tun. I wanted to get a pre boil volume of 7 gallons, so I fly sparged with just under 6 gallons of water.

However, I found I reached my pre boil volume with about 1.5g of water still in the cooler. Why would this be? Did I make a mistake in my calculations?

 

[azscoob]

I figure 1 pint of loss per pound of grain for absorption, that would put you at approx 1.625 gallons of loss for that grainbill.

That would be where the extra water came from, you figured too much absorption.

 

[944play]

Grain absorption is an estimate. I'm used to 1 gallon per ten pounds as a ballpark, but it sounds like Daniels has a much higher figure.

Also, this is another reason to like batch sparging. Absorption and deadspace can be ignored.

 

[mjtski]

I find that there is some amount of absorbtion in batch sparging but then again, I allow a 15 min rest before taking second runnings.

 

[NWMushroom]

I figure 1 pint of loss per pound of grain for absorption, that would put you at approx 1.625 gallons of loss for that grainbill.

That would be where the extra water came from, you figured too much absorption.

Sounds spot on, thanks!

 

[azscoob]

Sounds spot on, thanks!

Glad I could help!

 

[LVBen]

I'm used to 1 gallon per ten pounds

That sounds about right to me.