False Bottom and Water Calculations

[Kernel32]

I have a question regarding Mash & Sparge water volumes. I have used several of the calculators online and they all agree on the amount of water to use for mash & sparge on my brews.

My problem is that there is roughly 2 gallons of space between my false bottom and the kettle.

To accommodate this, I have been subtracting 2 gallons from the sparge water and adding it to the mash so I can get the total amount of calculated mash water above the false bottom.

When it comes time to sparge, I have been drawing off about 2 gallons of wort and adding it to the remaining volume of water to bring the sparge back to the original volume. This tends to drop the wort below the top of the grain bed initially.

Here is my question. Is there a better way to do this without a) buying a different false bottom or b) increasing the amount of water overall and thus increasing the boil time?

Or am I just overthinking this?

 

[flugelizor]

I would err on the side of less sparge water rather than dropping the mash level below the grain bed. Seems like you might be compacting the grain bed, and risking stuck sparge.

Some brewers don't sparge at all, particularly BIAB (brew in a bag) and BIAC (Brew in a conical). As long as your PH is in the desired range, large dead space, and less sparge should work just fine!

YMMV

 

[doug293cz]

What are typical strike water and sparge water volumes recommended by your software? Are you fly sparging or batch sparging?

Adding some of the first runnings wort to your sparge water in order to increase the sparge volume will reduce you lauter efficiency. I recommend against it.

When you vorlauf, you should recirculate at least 2X the volume under the FB in order to better homogenize the initial runnings. The volume under the FB is likely to have a lower SG than the wort in the grain bed, unless you do a recirculating mash. Having better homogeneity will improve you lauter efficiency.

Brew on

 

[Kernel32]

This was only my 3rd all grain brew and my first higher gravity beer.

The batch size is 5 gallons and the grain bill was roughly 18lb. According to the water volume calculator at brew365.com as well as others, strike was about 5.8 gallons, sparge about 3.5.

With the 2 gallons of dead space below the false bottom, I adjusted the strike to 7.8 gallons leaving only 1.5 gallons for sparge.

To sparge I am just laying a tube from the HLT on top of the grain bed. I do not do a recirculating mash.

The 6 quarts of left over water for sparge just didn't seem like enough. Thanks for the recommendations and suggestions.

 

[MagicMatt]

Do those calculators you mention account for your MLT deadspace? Most good ones do.

Is it a true 2 gallons of deadspace (as in you can't even draw it out via the ball valve), or just that there's 2 gallons below the false bottom, but you can still empty the vessel down to a lower true "dead space" volume?

If the former, and the 2 gallons is beneath your pickup tube, then that's a true deadspace and you'll need to add 2 gallons to your total volume to accommodate. There's no way around this that I'm aware of.

Essentially you have to look at it like this: you need 'x' amount of water collected for the boil. Let's call that number 7 gallons. Ignoring grain absorption just for simplicity, if you put 7 gallons into the MLT but you can only drain 5 (due to the 2 gallons of dead space), then obviously you'll have to put 9 gallons in to end up with 7 out.

 

[Kernel32]

It's the second. Two gallons below the false bottom. I can reclaim nearly all of it.

Thanks for the advice and suggestions everyone.

 

[Ozzy2001]

Yeah put enough water in your run so it will drain and drain it until it stops. Then dump out what's left in a measurable container. That's your dead space calc

 

[drksky]

Two words: dip tube

 

[MagicMatt]

Two words: dip tube

How does that help space below the false bottom? He's already stated he can reclaim nearly all of the liquid (with a dip tube, presumably).

 

[RoadKing]

You're way overthinking it. I had a system with 2 gallons under the bottom.
What I did was, fill the MLT with water to the false bottom. Then figure
1.25 qts per lb for mash water on top. If ya look at the qts. per lb. ratio including the water under the bottom, it would be 1.5 plus, but there is nothing you can do about that. For sparge, use double the amount
of water you mashed with. EZ..... alot of calculators will account for you running your grain bed dry, I like to keep water on top of the mash the entire time. Even If you use Beersmith, it will account for your underlet water, but still wants to run mash dry.