First time fly sparging- water calculations

[Talonracer67]

Just for fun I tried fly sparging this weekend. I normally batch sparge. My mash tun is a 10 gallon cooler, had a bazooka tube but I got nothing but stuck sparges. So I got a false bottom. Since i had the false bottom I thought I'd try some ghetto fly sparge. Took an extra 5 gallon mash tun and set in on a chair above my 10 gallon. Ran a hose from it to the piece of tinfoil with holes in it. Easy!! I made the Zombie dust clone from the recipe section. One thing that made me scratch my head, the recipe was for a 6 gallon batch so I was shooting for 7.5 gallons from my mash pre-boil. Put all the pertinent info into my trusty mash/sparge calculator. Thing was after my sparge water ran out and my tun emptied I was still over a gallon short!! I had to heat up an extra gallon and pour it in, so my last gallon was a batch sparge.

So why was the calculator so far off? I checked my final runnings and they were 1.025. Not complaining my expected OG was 1.065 and I hit 1.072. Very impressed but the water issue has me stumped. Next time I'm gonna heat extra water just in case.

 

[Yooper]

Which calculator did you use? Obviously there was something wrong in the set up.

I do use brewing software, but I always figure the sparge water amount by hand also. It's pretty easy. Grain absorbs about .125 gallons per pound of grain, so I figure 10 pounds of grain will absorb 1.25 gallons. I don't have any deadspace losses.

So, if I have 10 pounds of grain and I mash in with 15 quarts, I will get out 2.5 gallons of that. Then I"d need 4.5 gallons of sparge water to get to my boil volume of 7 gallons- or 8.25 gallons of water.

However, since I fly sparge, I only sparge up to my boil volume so I will generally start with quite a bit more as to not run the MLT dry.

 

[billl]

Why even bother doing calculations?

Mash as usual. Heat a bunch of water. Sparge until you get the volume you need. Use any extra hot water to clean the tun.

 

[Talonracer67]

Thanks bill and Yooper, I'm gonna do just that. I'm amazed how easy it was to fly sparge and the results were impressive.

Yooper I used this one http://www.brew365.com/mash_sparge_water_calculator.php

 

[mblanks2]

However, since I fly sparge, I only sparge up to my boil volume so I will generally start with quite a bit more as to not run the MLT dry.

Mash as usual. Heat a bunch of water. Sparge until you get the volume you need. Use any extra hot water to clean the tun.

+1 and +1