AG BHE and Grain Abosrption Q...

[rp5brew]

Gents-

First post so here we go!

I have been brewing for all of about 7 weeks now, first coopers LME batch was not good enough, so I switched to AG, built 2 Keggles for HLT/Brew Kettle and "jumped in with three feet" here is my question:

Equipment:
1- 13.2gal HLT
1-48Qt MLT
1- 15.5 BK

I started AG and took tons of notes to be sure and keep track of all the data the i was able to get from my installed system, batch sparging 3 5/8 gallons in two parts with a 1 3/4 gal mash-out. Every time that i did this in a whopping 5 brews if got pretty close to 18.4% grain absorption, [72-78% BHE ] it was like clock work on all the brew days.

I recently got the Keggles set up in a 3 tier system with ladders (awesome) and made a sparge sprinkler in the top of the cooler and set out on the first fly-sparge to try to get higher yield. after the 60-70 min fly sparge, i expected to have 11.75 gallons in the BK but came up with 13. 11.9% grain absorption/ 87.4% BHE. the efficiency came up and I was really happy with that, but i am really confused about the decrease in absorption by a half life. the only main changes that the system had was a doubling the recipe (10gal instead of 5) with the new keggles, and the fly-sparging.

has anyone come across the drastic change in GA% when switching sparging methods?

 

[Walker]

grain absorption of water should be constant regardless of the sparging method, I would think.

Are you properly accounting for dead space in your mash tun as a separate item than the grain absorption?

 

[rp5brew]

I did several test runs with the MLT that I have, and have had through all of my brewing. it has always been nuts on @ .125 gal.

 

[Walker]

Ok. I was just checking to see if you were accounting for it as a separate item and not just lumping all volume losses into one item called "grain absorption".

Did you mash thinner or thicker on your 10 gallon batch?

 

[Walker]

btw: wtf is bhe?

edit: nevermind... I just figured it out. brew house efficiency.

 

[rp5brew]

all brews have been 1.25 mash thickness.

 

[Walker]

Well... I guess I am useless here. I've seen my efficiency go up with different sparge methods, but grain absorption has always been a rock-solid constant for me.

The only times I have ended up with more or less pre-boil volume in the kettle is because I goofed and mashed or sparged with the wrong amounts of water.