Question on my new false bottom

[LarryC]

A while back I made a false bottom for my 10 gallon cooler/mash tun. The false bottom is made from a deep dish pizza pan and I drilled about a million holes in it (felt that way at least). This past weekend was the first time I used it and because the FB has a height about equal to the 1 gallon line in the mash tun, I added an extra gallon to my strike water (BeerSmith said 18 quarts and I put in 22). Everything went very well but when I did the math the next day it looks like my mash efficiency was a bit low - 71%.

Was the extra strike water an issue? This seemed like the right thing to do but now I'm not so sure. Thoughts?

 

[LarryC]

Oh come on, with all you smart brewers out there, somebody has a thought on this, right?

 

[bsomogyi]

It could be your water to grist ratio, but I think you did the right thing. The amount of water in the false bottom should be deducted from your strike water calculations when determining mash thickness. But it also could be many other factors that are affecting efficiency (your systems mash process, etc).

 

[lumpher]

yes, that will make a difference. you pour in the water, it goes into the false bottom; the grain doesn't. that water becomes extra dilution water. you do need to factor that in

 

[LarryC]

Lumpher - I did factor that water into the mash calculation but maybe I'm not looking at it right. Here's what I did - I added 4 quarts to the BeerSmith suggested strike water amount to make up for the dead space under the FB. When I got my first runnings, I measured the amount and then just added the difference between my first runnings and the total amount of pre boil wert BS said to use for the boil. I realize that there was probably an extra gallon of water in there but it seemed like I would have accounted for it in the sparge amount. Am I wrong on that?

bosomogyi - one thing I probably do need to watch next time is my flow rate when getting my first runnings and after sparging. With just a SS braid in there, the grain would slow down the drainage and I could pretty much open the valve all the way and get a proper runoff rate. I didn't even check for this but I imagine with the braid sitting under the FB, it wasn't clogged and the runoff probably drained a lot faster than it should of.

 

[lumpher]

no, you're not wrong. what i mean is you do need to add in a little extra grain to account for it. your extraction rate will be lower than your original calculation since a gallon of your water is not being used for mashing. are you calculating for that?

 

[LarryC]

no, you're not wrong. what i mean is you do need to add in a little extra grain to account for it. your extraction rate will be lower than your original calculation since a gallon of your water is not being used for mashing. are you calculating for that?

I guess I'm not calculating for that and I'm not sure exactly how I would do that. Suggestions?

 

[duboman]

Pour water into the tun and drain. Once all runnings are out then measure the remaining amount left, this becomes the number you enter in your equipment profile for tun dead space.

Assuming all your other numbers in the profile are correct BeerSmith takes it all into account when calculating your recipe and volumes so you don't need to make further adjustments on the fly

As for efficiency there are a lot of factors and are you talking about mash/Lauter or brew house efficiency?

 

[LarryC]

duboman - if I take the measurement as you suggested and enter that into my BS equipment values, wouldn't that change with different amounts of grain in the recipes?

I did take a look at my tun in the BS equipment listings and I see it has a value for dead space (was set to .25 gal). I changed it to 1 gallon and then looked at my recipe but the amount of strike water was unchanged.

I was measuring the mash/lauter efficiency using Brewer's Friends calculator (grain bill, volume, pre-boil SG). I wasn't in too bad of shape but I would like to see it closer to 75% and as I mentioned, I may have been too fast on my run off so I'll be watching that more closely next time.

 

[duboman]

duboman - if I take the measurement as you suggested and enter that into my BS equipment values, wouldn't that change with different amounts of grain in the recipes?

I did take a look at my tun in the BS equipment listings and I see it has a value for dead space (was set to .25 gal). I changed it to 1 gallon and then looked at my recipe but the amount of strike water was unchanged.

I was measuring the mash/lauter efficiency using Brewer's Friends calculator (grain bill, volume, pre-boil SG). I wasn't in too bad of shape but I would like to see it closer to 75% and as I mentioned, I may have been too fast on my run off so I'll be watching that more closely next time.

The strike water won't change as that is the amount you mash at but the sparge volume will change to ensure you get the right pre-boil volume to account for evaporation and kettle loss to archive your desired post boil volume.

Mash/Lauter efficiency will depend on crush, size of grain bill, pH, and temperature ensuring conversion.

Your efficiency isn't bad and the couple points really won't make a huge difference. It's more important to be consistent then chasing numbers so if you are always at 71% that's where you want to be and then just increase the base malt to hit your desired gravity.

Simple thing to do is adjust for a better crush and you can easily bump your efficiency a few points