Sparge water - I always need another couple of litres.

Hi there,

I fly sparge, and always find if I use the total water volume suggested by BS I am 2-3 litres short. so always add manually. But, I would love to know where I am going wrong in BS! I have checked my equipment profiles and mash profiles and cannot see anything obviously wrong.

Cheers,

Andy.

sounds like you need to bump up either your loss to deadspace in the mash or grain absorption.

are you short at the end of the mash or after the boil?

Hi there, It's not deadspace as I have none in my MAsh Tun (SS Brewtech). But  I am just looking at the gran absorption now myself, I suspect it's that. But, it would mean the std BS setting is way out.

Another question, do you use all your sparge water, i,e you wring every last drop out of the Mash tun (without forcing it out of course), or do you leave a coupe of litre in the tun. So that means, using BS, you use all the water it suggests as Total Water Needed, So, total water in, less absorption = Pre Boil Volume. It seems that is how BS is set up.

Greetings andy - I also had problems with being short at the end of the mash and into the boil kettle. I ended up changing numbers in BS to make up the difference.  If I recall, the numbers I changed/played with were in the dead space and in the trub loss as toots suggested.  Also, unless you altered the absorption rate, it should remain constant and has proven to be pretty accurate for me.

Regarding the sparge water - what I find myself doing is actually creating slightly more sparge water in my liqueur kettle than called for.  Then, I continue to fly sparge until I have collected all the extract the recipe calls for....typically about 8.3 gallons for a 60 minute boil.  I'll also monitor the gravity of the final runnings.  I typically stop sparging around 1.009, which will typically be the gravity when I hit my 8.3 gallons.

I wasn't familiar with the brewtech, just looked it up, very cool design how it pulls from the very bottom!!

So the trub loss would only come in to play if you're coming up short at the very end, after transferring to your fermenter.  If that's indeed where you're coming up short, then the evaporation rate would come into play as well. 

If not, I think it comes down to deadspace (which after looking at the brewtech you have me convinced that would be zero), and the absorption rate.  I'm with Keller in the opinion that the latter shouldn't change from batch to batch, and it shouldn't need significant tweaking from you.  Big picture, if you're looking for a quick fix, add the couple liters you always need to deadspace.

I personally didn't have to change these numbers, lucky I guess.  I do generally run the grains dry.  I sometimes measure the gravity of final runnings like Keller suggests, but not as much as I should because I've never seen it below 1.009 (this is where tannins begin to release).