these numbers sound right?

[Joe028]

Did my first AG last week and everything went fairly smooth. I am going to brew again this weekend, but I want to try and get a little closer on target with the amount of water needed and all that. It seems the calculators that I used in beersmith underestimated a bit.

Does this sound about right? I lost 1.2 qt/lb in the mash and batch sparge process.
I lost 1.75 gal in a 60 minute boil. These amounts seemed quite high to me and wondered if anyone had similar results.

I use a 5 gal round cooler with SS braid for mashing and a keggle for boiling. Thanks

Joe

 

[david_42]

That's a bit high, I normally lose around 0.8 quarts per pound. How much is lost in the boil depends on how vigorous a boil I do. 1.75 gal. is about right.

 

[Orfy]

Don't forget all that you loose will not be absorbtion. Some will be dead space in the mash tun.

In theory if you fill to level "x" on mashing and it takes 15qt
Drain off and get 7 qt then your absorption is not 8qt
On batch sparging if you fill up to level x and it takes 12qt (There should be no absorbtion) Then you have 3 qts dead space so your absorbtion is 5qt.

Hope that make sense. I'm sure someone will say If I have got it wrong.

 

[Joe028]

care to expand on the mash tun deadspace? I have had trouble grasping that concept from several sources. Is this deadspace a spot in the mash tun that you can physically see? I figured i had very little dead space because i am not using a false bottom, but a SS braid instead. Maybe i have more than I thought...

 

[Blender]

Deadspace refers to the liquid that you cannot drain out of the cooler. Fill it with a couple of gallons of water and let it drain as you do with the wort. I tilt my cooler at the end of the running.
Then pour the remaining liquid into a measure and see what is left. For my cooler it is about a pint.
My grain seems to absorb around .13 quarts per pound mashed.

 

[ajf]

Weigh the empty cooler before you start. Weigh it again when you finish sparging. The difference between the two weights will be the amount of grain and water left after the sparge. Subtract the weight of the dry grain that you mashed, and you will be left with the weight of water absorbed by the grain, and left in the dead space. (I don't see that it makes any difference if the water is absorbed, or left in dead space).

-a.

 

[Orfy]

(I don't see that it makes any difference if the water is absorbed, or left in dead space).

-a.

Because if you increase the grain grain bill the the absorbtion will increase but the dead space wont. Throws the calculations out.

Mash Tun Loss = Absorbtion rate*Grain bill+Dead Space

 

[jcarson83]

If you want to get technical I think your boil off will have to do with your altitude and the relative humidity.

 

[Joe028]

I wish I had checked the volume of water extracted from the mash because then I would have better notes, but instead I just recorded volume after sparging. I will pay closer attention this weekend on my second AG.

I did a mash followed by two separate batch sparges (due to cooler size), I don't know if that may have had any effect on my losses, but probably not.

Another question for you folks though... I needed top off water both post mash and post boil, because of my underestimates. I topped off with plain boiled water in both instances. I still hit my OG right on so I think my efficiency was fine, but should I be running that water through the grain as a sort of extra sparge, or would that extract more tannins possibly? Hopefully if I get my system figured out, the idea of topoff water would be a non-issue.

 

[Orfy]

If you hit your target OG then you don't need to sparge with the top up water.
I think a rule of thumb is to stop sparging when your run off gets to around 1010.

I'm on my 7th AG and I'm still figuring figure.
I'm thinking if I'm happy with my brews and my volumes are working then I'm done.

I also do two batch sparges.

 

[ajf]

Because if you increase the grain grain bill the the absorbtion will increase but the dead space wont. Throws the calculations out.

Mash Tun Loss = Absorbtion rate*Grain bill+Dead Space

I agree with this if you make significant changes to the grain bill.

-a.