First AG Batch Math

I’m prepping for my first AG batch this weekend and have run into a mathematical dilemma. What do I have wrong?

I’m using a 5 gal HLT and 5 gal MLT.

Dry Dock Urca Vanilla Porter Kit has 11.875 lbs of grain.

Strike Water = 1.25 quarts x 11.875 = 14.84 quarts (3.71 gal)

Sparge Water = 2 quarts x 11.875 = 23.75 quarts (5.9 gal)

So if my calculations are correct, that’s almost 10 gallons of water that will be needed for a 5 gal batch? Does that sound right?

Furthermore, 5.9 gal of sparge water wont fit in my 5 gal HLT. Am I screwed?

Are you batch sparging? If so, just use enough soarge water to hit your boil volume.

I planned to continuous sparge. Is that not an option.

How do I know what my preboil volume should be if I’m aiming for 5 gal?

Newbie questions, I know. Thanks

Sparge is not a function of grain weight - it’s by kettle volume. You’re also forgetting that the grain is going to absorb ~1.5 gallons of wort (0.125 gallons per lb). So if you want to put six gallons in the kettle, subtract the first runnings to find the sparge: 6 - (3.71 - 1.5) = ~3.75 gallons.

I think that makes sense. The only part I dont understand is the bit about Sparge being a function of kettle volume. Are you saying that the amount of sparge water you should use is dictated by the size of your kettle? That doesn’t make sense to me.

I’m pulling this from memory so please don’t quote me on this. I batch sparge, but I did go to an AG class at NB Milwaukee. the instructor took running using a refractometer through out the sparge,and at a certain point you will get gravity readings on your runnings less than 1.010?, at which point it serves no further purpose to keep collecting the runnings. The most important thing was to get the correct preboil gravity more than the volume. If I remember correctly from the class our volumes were a little low, but we did leave water in the HLT, but got correct gravities. Please feel free to correct me if I misremembered.

I think that makes sense. The only part I dont understand is the bit about Sparge being a function of kettle volume. Are you saying that the amount of sparge water you should use is dictated by the size of your kettle? That doesn’t make sense to me.[/quote]
The volume you want in the kettle, i.e. the amount of wort you want to collect.

[quote=“mvsawyer”][quote=“Chris-P”]Are you saying that the amount of sparge water you should use is dictated by the size of your kettle? That doesn’t make sense to me.[/quote]The volume you want in the kettle, i.e. the amount of wort you want to collect.[/quote]Precisely.

Got it. Thanks gang!

You can double check you math with a program like MashWater3.3

http://gnipsel.com/beer/software/beer-software.html

Batch or continuous sparging doesn’t matter. The water used is the same.

For a 5 gallon batch, I actually use 5.3 gallons in the fermentor so that I end up with 5 gallons, or just over, in the keg.

To do that, for a 60 minute boil, I need to collect about 7.5 gallons of wort. Depending on your method and length of boiling, YMMV