Having issues calculating mash water with a false bottom

[Fathand]

My brewing partners and I use a keggle with a pico style false bottom as our MLT. The false bottom is such that about 2.5 gallons of water reside under it when we add our mash water and grain. My question is how do we equate for this water (specially when we do 5 gallon batches)?

We have been adding an extra 2 gallons of water but we have been getting less than stellar efficiency, last batch we 65%. If we don't add that water it looks as if the mash is way to thick and a lot of grain is not in contact with any water.

How do we handle this dead space?

 

[Reno_eNVy]

That's a TON of deadspace. You really need to re-evaluate your setup.

Why can't you get the wort from under the false bottom? Isn't that the entire point? I think you need to add some kind of dip-tube under the false bottom.

 

[crackhead7]

are you direct firing the keggle during the mash? if not consider switching to a braid. how are you sparging? batch or fly? if I understand correctly your stated dilemma is wanting the entire original mash water vol. contacting the grains vs. that large amount sitting under the mash. AS I See it if you are direct firing convection should be a help by ciculating the water. If you need to add the extra water just subtract that from your sparge volumn but 2 1/2 gallons is a ton but i could see how that happens witht he base provided with that false bottom. you might want to try to trim that base in half with some shears if possible, but i have never seen it in person, your guess is as good as mine.

 

[Fathand]

are you direct firing the keggle during the mash? if not consider switching to a braid. how are you sparging? batch or fly? if I understand correctly your stated dilemma is wanting the entire original mash water vol. contacting the grains vs. that large amount sitting under the mash. AS I See it if you are direct firing convection should be a help by ciculating the water. If you need to add the extra water just subtract that from your sparge volumn but 2 1/2 gallons is a ton but i could see how that happens witht he base provided with that false bottom.

Yes we are direct firing. We are fly sparging. We did recirculate the wort this last batch. What we did was drain off about 2 quarts of wort every 15 minutes during the mash and then add it back on top. We also stirred the mash at this same 15 minute intervals.

Eventually we'd like to get a pump so we can recirculate continuously throughout the mash.

Here's the false bottom we are using...
Stainless Steel PICO Style Keg Kettle False Bottom

 

[crackhead7]

the only reason I could see for low eff. with this is becasue you fly sparge with small batches. You might not be sparging enough, due to the decrease in sparge vol becasue of the compinsation for the 2 gals added to the mash. It really shouldn't matter as fly sparging I just run until I have my preboil volumn which is 12.5 gals for a 11 gal batch (which is 10gals into kegs or bottles). If its still an issue I the options as either switch to batch sparging, or collect more wort and boil longer. Do you mill your own grains?

 

[Fathand]

No we mill our grain at the LHBS.

We can also formulate our recipe for 65% efficiency and up the grains a bit too. I know not to get too hung up on efficiency but I just want to figure out ways to increase it, if possible.

 

[crackhead7]

how long have you been doing all grain batches? I asked about the mill because before i got my own mill my eff. was all over the place think for some reason i was getting an inconsistent crush from the LHBS. I used to shoot for 70% eff. but that has continually kept creeping up as I have profected my process.

 

[badhabit]

that's a ton of deadspace. You really need to re-evaluate your setup.

Why can't you get the wort from under the false bottom? Isn't that the entire point? I think you need to add some kind of dip-tube under the false bottom.

+1

 

[Fathand]

I guess I was wrong to use the term deadspace because we are able to drain all the liquid from the tun except a cup or two.

That 2.5 gallons of water is simply water that does not come in contact with the grain during the mash as that water is under the false bottom.