Electric Brewing Supply 30A BCS Giveaway!


Home Brew Forums > Home Brewing Beer > All Grain & Partial Mash Brewing > Honest, I looked. Mash Tun False Bottom vs Mash Ratio question
Reply
 
LinkBack Thread Tools
Old 08-21-2013, 10:08 PM   #1
MuddyCreek
HBT_SUPPORTER.png
Feedback Score: 0 reviews
 
MuddyCreek's Avatar
Recipes 
 
Join Date: Aug 2012
Location: Butte, MT
Posts: 538
Liked 149 Times on 97 Posts
Likes Given: 109

Default Honest, I looked. Mash Tun False Bottom vs Mash Ratio question

So I've looked around some threads, done a search, looked through my various books and I finally accept that I'm just going to ask the question...

I generally do a mash ratio at around 1.33. It's a nice middle ground and I've been happy with the results generally speaking. But here's where it gets complicated...

I have a Coleman 7 gallon cooler/mash tun. I was using a stainless braid with it, but that was giving me some stuck mash issues. So, I put together a simple PVC platform with a custom-built screen over the top to serve as a false bottom and keep the grain off the braid. It works great.

However, I need about 1.5 gallons of water underneath the bottom to bring the level up to the base of the screen. (problem due to the placement of the thermoprobe. I have to have the false bottom a little higher than I would have liked it otherwise.)

Anyway, I simply fill the tun up to the base of the false bottom with liquor and then add my mash volume along with my grain. This keeps my grain hydrated at the proper amount BUT, since I run a HERM system, I technically have a lower gravity after my mash than I am expecting. This isn't really an issue since I match my sparge amounts as well as I can and then boil down to my target fermenter amount. (Ultimately, it comes down to math and I have a spreadsheet that pretty well spells it all out for me.)

My question is sort of just academic... Is the mash ratio water amount expected to be in addition to the liquor underneath the false bottom (I assume so, otherwise your mash would be too thick.) and if so, are there specific formulae that take your 'under-bottom' liquor amount into account when figuring the expected pre-boil gravity?

It could be this is just one of those 'learn your equipment' things. Like I said, I either adjust my sparge amount to account for the extra liquor in the first runnings from the under-bottom or I boil down as necessary and do the math from either of those two points.

ideas and input welcome. I've just never seen any specific discussion of under-bottom liquor amounts and how that relates to your mash and sparge volumes.

__________________
Muddy Creek Brewery - Opening Fall 2014
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


Our Lineup

Muddy Creek Chocolate Stout: So good we named the brewery after it!

Skinny Cow IPA: In India, cows are sacred, that doesn't mean they feed em...

Good Time Wheat Ale: What the hell, I'll have a Good Time!

No Paddle Amber Ale: Up the creek without a paddle, may as well enjoy the ale.

Dirty Blonde Ale: You know you want one.

MuddyCreek is offline
 
Reply With Quote Quick reply to this message
Old 08-23-2013, 12:33 AM   #2
dyqik
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jun 2013
Location: Arlington, MA, Massachusetts
Posts: 611
Liked 79 Times on 71 Posts
Likes Given: 1

Default

Beersmith and the like add the dead space in the tun for the strike volume on top of the volume indicated by the mash thickness ratio. "Dead space" is probably the search term you are looking for.

__________________
dyqik is offline
 
Reply With Quote Quick reply to this message
Old 08-23-2013, 02:35 PM   #3
MuddyCreek
HBT_SUPPORTER.png
Feedback Score: 0 reviews
 
MuddyCreek's Avatar
Recipes 
 
Join Date: Aug 2012
Location: Butte, MT
Posts: 538
Liked 149 Times on 97 Posts
Likes Given: 109

Default

Thank you. Appreciate the feedback.

__________________
Muddy Creek Brewery - Opening Fall 2014
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


Our Lineup

Muddy Creek Chocolate Stout: So good we named the brewery after it!

Skinny Cow IPA: In India, cows are sacred, that doesn't mean they feed em...

Good Time Wheat Ale: What the hell, I'll have a Good Time!

No Paddle Amber Ale: Up the creek without a paddle, may as well enjoy the ale.

Dirty Blonde Ale: You know you want one.

MuddyCreek is offline
 
Reply With Quote Quick reply to this message
Reply



Quick Reply
Message:
Options
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Stout Tanks Mash Tun vs Blichmann Mash Tun (w/ false bottom) julian81 Equipment/Sanitation 38 03-27-2014 12:35 AM
mash tun false bottom - will the AIH false bottom work? BullGator All Grain & Partial Mash Brewing 4 08-12-2013 01:34 AM
Mash tun false bottom and mash thickness shushikiary All Grain & Partial Mash Brewing 2 11-29-2011 08:13 PM
Mash Tun/False Bottom Noob Question JLW DIY Projects 1 11-16-2010 11:04 PM
Mash in Keggle - False Bottom vs. amount of mash water Griffsta All Grain & Partial Mash Brewing 2 03-24-2009 01:09 PM