False Bottom Question

[Buttwidget]

I picked up a false bottom from Adventures in Homebrewing and am extremely happy with how well it fits into my keggle. It was certainly made specifically for this application.

I have a question about it though. In the instructions it says to fill the keggle with water until the water just touches the false bottom (about 2-3 gallons) and then calculate the water for the grains at that point. I called and asked, shouldn't I just decrease my mash thickness by adding 2-3 gallons of water so I get the correct strike temperature? The gentleman at the shop said, "no".

Maybe I'm over thinking this, but wouldn't 2-3 gallons of water have enough thermal mass to affect my strike temperature causing my mash temp to begin too low?

I should be running my first test in about a month, but was curious as to what the wisdom of the masses was on this topic.

Thanks!

~widget

[anday6]

You're right, those 2-3 gallons will affect the needed strike temp. Do you add water to grain or grain to water?
If grain to water, that's easy, just do like you said and increase your strike volume from what you need for mashing. The extra water won't exactly change your thickness since it's separate (not exactly true since they are in the same vessel, but unless you're recirculating you can simplify).
If you go water into grain, it would be good to just add that volume of water at your strike temp to reduce any effect.

[Buttwidget]

I add grain to the water. That's what I thought, even though the grain has been suspended above much of the liquid, the conduction of heat throughout the liquid seems that I would need to calculate strike temp for the full volume of water. It will be easy enough since I use BeerSmith, but I wanted to confirm my thinking.

I will be using a HERMS setup, so I could mash as described in the directions and step the temp from there, but I don't want to add yet another variable to my first brew day (if I can help it).

You make a good point about the thickness of the mash, it will be just as thick as it would have been since the grain is being suspended above the additional water volume. I need to think about this a little more... I wonder what the effect (if any) of more liquid below the false bottom would have on the mash.

I'm going to have a 10th Anniversary Ruination and think about it some more.

Feel free to weigh in!

~widget

[beach]

I use that same FB and recirculate during the entire mash through a HERMS. I set my water/grain ratio in BeerSmith based on what I want (usually around 1.5 qt/lb, ymmv) which gives me my strike and sparge liquor volumes. I then take 2.5 gal of the sparge liquor and add it to the strike liquor to make up for the foundation water below the FB. I count it as sparge water since I recirculate it during the rest. Works for me.

Beach

[Kbar]

I use that same FB and recirculate during the entire mash through a HERMS. I set my water/grain ratio in BeerSmith based on what I want (usually around 1.5 qt/lb, ymmv) which gives me my strike and sparge liquor volumes. I then take 2.5 gal of the sparge liquor and add it to the strike liquor to make up for the foundation water below the FB. I count it as sparge water since I recirculate it during the rest. Works for me.

Beach

I thought that Beersmith had a setting where you could enter dead space volume for the mash tun so that it would calculate your needed temperature and strike water volume. Need to check now...........

[scotchpine]

I picked up a false bottom from Adventures in Homebrewing and am extremely happy with how well it fits into my keggle. It was certainly made specifically for this application.

I have a question about it though. In the instructions it says to fill the keggle with water until the water just touches the false bottom (about 2-3 gallons) and then calculate the water for the grains at that point. I called and asked, shouldn't I just decrease my mash thickness by adding 2-3 gallons of water so I get the correct strike temperature? The gentleman at the shop said, "no".

Maybe I'm over thinking this, but wouldn't 2-3 gallons of water have enough thermal mass to affect my strike temperature causing my mash temp to begin too low?

I should be running my first test in about a month, but was curious as to what the wisdom of the masses was on this topic.

Thanks!

~widget

Does the dead space need to be this large to keep from scorching grains with direct fire. I have a keg to use for this and was thinking to go this route instead of continuing to use a cooler.

[Buttwidget]

That's what they say its good for, I've not used it for that, but with that much space direct fire seems like it wouldn't be a problem.

~widget

[Buttwidget]

Hey, kbar. The deadspace item is for calculating volume for wort lost in the lines etc. I would assume that the extra volume is used to measure strike temp, but I'll have to play with it and see.

Edit:
I went and tested it, and it certainly does adjust the water volume and temp accordingly. I'm going to trust BeerSmith on this, its always done well by me.

~widget