Question about dunk sparging grain absorption rate and efficiency

[VT_jlee]

I tried out dunk sparging last night for the first time. I use biabcalulator.com to get my water volumes nailed down, and it is typically reliable. I plugged in all of the same numbers I usually use yesterday and after the mash I ended up with ~0.5 gallons of extra wort pre-boil but my pre-boil gravity was close to what I originally expected. In order for this to happen, my grain absorption rate would need to be drastically reduced and my efficiency would need to increase by about 10%.

I was wondering what you folks usually use for grain absorption rates and efficiency when you dunk sparge.

 

[cyberbackpacker]

On your dunk sparge, there will be no grain absorption, as it is already saturated from the main mash. So, if you calculated that into your dunk sparge, that could definitely account for your extra volume.

 

[VT_jlee]

On your dunk sparge, there will be no grain absorption, as it is already saturated from the main mash. So, if you calculated that into your dunk sparge, that could definitely account for your extra volume.

Ohhhh.. of course! That's exactly what I did. I used a little over half a gallon to dunk sparge, and that is how much I overshot my pre-boil gravity. Thanks for pointing that out.

 

[cyberbackpacker]

Glad to help!