[bluesman]

If you inadvertantly measured lets say 18lbs or more. You should see the result of that in your remaining grain bag. It would be a hassle to weigh the remaining grain. Just a thought.

[denny]

what was the gravity of the first runnings?

Kai

I don't recall off the top of my head.  I'll get out my notebook when I get home and let you know.

[denny]

If you inadvertantly measured lets say 18lbs or more. You should see the result of that in your remaining grain bag. It would be a hassle to weigh the remaining grain. Just a thought.

I appreciate the thought, but I'm positive I weighed out 17 lb.

[denny]

OK, here are the numbers...

17 lb. of Best pils malt.  Mashed with 6.5 gal.  1st runoff was 5.5 gal. of 1.074.  Sparged with 5.75 gal.  Total boil volume was 11.25 gal. of 1.052.  1.052 was my target gravity for the entire batch!

[Kaiser]

OK, here are the numbers...

17 lb. of Best pils malt.  Mashed with 6.5 gal.  1st runoff was 5.5 gal. of 1.074.  Sparged with 5.75 gal.  Total boil volume was 11.25 gal. of 1.052.  1.052 was my target gravity for the entire batch!

According to these numbers I get a conversion efficiency of ~95%. But with that an overall efficiency of 97% should not be possible unless you convert more starches during sparging.

But what is also odd is that you have a grain absorption of 0.06 gal/lb. This is about half of what brewers generally see. Did you correct the volumes for temperature?

Kai

[blatz]

81.2% as of my latest order, from the Sept 09 lot, which is probably what you got (received it personally in early Dec).

[denny]

OK, here are the numbers...

17 lb. of Best pils malt.  Mashed with 6.5 gal.  1st runoff was 5.5 gal. of 1.074.  Sparged with 5.75 gal.  Total boil volume was 11.25 gal. of 1.052.  1.052 was my target gravity for the entire batch!

According to these numbers I get a conversion efficiency of ~95%. But with that an overall efficiency of 97% should not be possible unless you convert more starches during sparging.

But what is also odd is that you have a grain absorption of 0.06 gal/lb. This is about half of what brewers generally see. Did you correct the volumes for temperature?

Kai

I forgot to add that I added a gal. of boiling water before the mash runoff, so the total volume of water into the mash was 7.5 gal.  Still, though, I noticed a lower than usual absorption.  I did not correct volumes for temp., but the volumes I measured were at no more than 150F.  There shouldn't be much difference in that, should there?

[Hokerer]

the volumes I measured were at no more than 150F.  There shouldn't be much difference in that, should there?

Isn't the volume difference between room temp and boiling something like 4%?  If you're measuring at 150F, that's about halfway so maybe 2%?  So, if you measured 10 gallons at 150F, it would really be 9.8 gallons - not a big difference but some.

[Kaiser]

I forgot to add that I added a gal. of boiling water before the mash runoff, so the total volume of water into the mash was 7.5 gal.  Still, though, I noticed a lower than usual absorption.  I did not correct volumes for temp., but the volumes I measured were at no more than 150F.  There shouldn't be much difference in that, should there?

That makes things a little more realistic. I put the numbers you gave me into my spreadsheet, I assumes 83% extract from the malt and 4% moisture content. Note the error analysis on the side. I took the liberty and made a guess how accuate your nunbers are.



Were the 1 gal that you added to the mash part of the sparge water volume? If no then your grain absorption is aboput 0.13 gal/lb. This is typical. If yes, your grain absorption is 0.07 gal/lb. This is significantly less and the cause of your high batch sparging efficiency. At least the problem of the conversion efficiency being lower than the efficiency into the kettle is solved. You had me questioning my theroy for a moment.

Kai

[denny]

Were the 1 gal that you added to the mash part of the sparge water volume? If no then your grain absorption is aboput 0.13 gal/lb. This is typical. If yes, your grain absorption is 0.07 gal/lb. This is significantly less and the cause of your high batch sparging efficiency. At least the problem of the conversion efficiency being lower than the efficiency into the kettle is solved. You had me questioning my theroy for a moment.

Kai

Thanks for your analysis, Kai!  The extra gal. was added before the mash runoff and therefore was not part of the sparge volume.  That means my absorption was in line with what I normally get.  So, you're still a genius! 

[Kaiser]

So, you're still a genius! 

Thanks, but not quite. Now that your grain absoption is not out of line I can't explain how you got ~92% lauter efficiency when batch spatging a ~1060 beer. With just one sparge I would that expect to be more like 85-87%. You could get close to 90% with 2 sparges.

I guess we'll have to see how future batches with that malt turn out.

Kai