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**MalFet** · 01-09-2013, 11:30 PM

Quote:

Originally Posted by Viejo

OK, I'll bite. How do I parse the results to determine the culprit? I haven't figured out how to do that.

One thing that's different in my latest session is I was mashing quite a bit more grain than usual, looking for a higher gravity. So, the mash was thicker. Also, in contrast to previous sessions, I didn't heat the sparge water quite so hot (near boiling before), which probably reduced the fluidity some. How much do temperature and water/grain ratio matter in a batch sparge system? I've been splitting the total sparge volume into two equal infusions. Maybe I should go back to a single sparge?

You'll bite? I didn't realize I was fishing.

The short answer is that you've got to figure out the total extracted sugars in your grains and then divide that by your total strike water. If you've got, for example, ten pounds of two-row at 35 points per pound per gallon and you strike with 6 gallons, you'd expect your first runnings to be (10 * 35 ppg / 6 gallons = 58 points, or 1.058). If you're significantly below that, you've got conversion problems.

Kaiser's got a comprehensive worksheet at his website: http://braukaiser.com/wiki/index.php?title=Troubleshooting_Brewhouse_Efficien cy

As for the other stuff, it depends. The water to grist ratio shouldn't effect your conversion, but if there's more grain it will absorb more water, which means you're leaving sugars behind. Big beers tend to have lower efficiency on most systems. Some report that sparge temperature matters, though I'm skeptical. At the very least, I often sparge with cold water and notice no effects.

Denny · 01-10-2013, 12:10 AM

Quote:

Originally Posted by Viejo

OK, I'll bite. How do I parse the results to determine the culprit? I haven't figured out how to do that.

One thing that's different in my latest session is I was mashing quite a bit more grain than usual, looking for a higher gravity. So, the mash was thicker. Also, in contrast to previous sessions, I didn't heat the sparge water quite so hot (near boiling before), which probably reduced the fluidity some. How much do temperature and water/grain ratio matter in a batch sparge system? I've been splitting the total sparge volume into two equal infusions. Maybe I should go back to a single sparge?

The more grain you use, the more your efficiency will decrease unless you increase the amount of sparging you do to make sure you get all the sugars out. Of course, that means you need to boil more in order to get down to your target volume. Most people simply accept that higher gravity batches means reduced efficiency. But for me, that doesn't take effect until I'm into the upper 80s for an OG. I've started using about a 1.75 qt./lb. mash ratio and it has upped my efficiency a couple points. Sparge water temp doesn't really play a role in efficiency unless your mash hasn't completely converted. In that case, using 190ish sparge water can help comete conversion. But viscosity of the wort doesn't really play a role. Kai Troester has proven that with his cold sparge experiment. Again, if your efficiency increases with hotter sparge water, it's because your mash wasn't fully converted before. Kai also has an excellent article on conversion efficiency that might be useful to you. My experience is that splitting the spagre into 2 batches does so little, if anything, to increase efficiency that it isn't worth my trouble. The thing that many people never consider when measuring efficiency is the extract potential of the grain. Most people just use an average number or whatever their software tells them, when in reality the potential can vary widely form batch to batch of grain. Unless you have a lot analysis for the bag you're using, you really don't know what to expect. If the actual potential is lower thathe figure you use, it could appear that your efficiency is lower than it really is.

**jdub1782** · 01-10-2013, 12:19 AM

Quote:

Originally Posted by Denny

G. I've started using about a 1.75 qt./lb. mash ratio and it has upped my efficiency a couple points. .

Denny, are you using 1.75qt.lb for your initial infusion? I have always used the recommended 1.25qt/lb (if it would fit in my MT), but have recently switched to a larger MT and was wondering if a lower density mash would increase my efficiency.

**diS** · 01-10-2013, 10:20 AM

Kai states that thinner mash increase efficiency in some way:

Quote:

A significant difference was however found in the efficiency. The brewhouse efficiency of the tick mashes remained almost constant between 58 and 60% over the temperature range of the experiments, but the brewhouse efficiency for the thinner mash showed a strong dependency on the temperature and was always better than the efficiency of the tick mash. That leads to the conclusion that thinner mashes perform better and allow for better extraction of the grain. Briggs also reports that thinner mashes can convert more starch but that most of the conversion potential is reached at a water to grist ratio of 2.5 l/kg [Briggs, 2004]

TyTanium · 01-10-2013, 01:40 PM

Quote:

Originally Posted by Denny

The more grain you use, the more your efficiency will decrease ...But for me, that doesn't take effect until I'm into the upper 80s for an OG.

Ditto

Quote:

Originally Posted by Denny

The thing that many people never consider when measuring efficiency is the extract potential of the grain. Most people just use an average number or whatever their software tells them, when in reality the potential can vary widely form batch to batch of grain. Unless you have a lot analysis for the bag you're using, you really don't know what to expect. If the actual potential is lower thathe figure you use, it could appear that your efficiency is lower than it really is.

+1 Easily explains variance of a few points either way. Couple that with measurement variance and +/-5% isn't surprising to me.

**BigRedHopHead** · 01-10-2013, 02:45 PM

Quote:

Originally Posted by jdub1782

Denny, are you using 1.75qt.lb for your initial infusion? I have always used the recommended 1.25qt/lb (if it would fit in my MT), but have recently switched to a larger MT and was wondering if a lower density mash would increase my efficiency.

Not to speak for Denny but I believe 1.75qt/lb is his initial infusion. After reading Kai's work on mash thickness all my batches have been in the 1.75-2.0qt/lb range and my efficiency has improved (usually high 70's to 80). If you now have the space try it out.

Denny · 01-10-2013, 03:25 PM

Quote:

Originally Posted by jdub1782

Denny, are you using 1.75qt.lb for your initial infusion? I have always used the recommended 1.25qt/lb (if it would fit in my MT), but have recently switched to a larger MT and was wondering if a lower density mash would increase my efficiency.

Yeah, for the initial infusion. It increased mine a bit.

**AZ_IPA** · 01-10-2013, 04:42 PM

Denny, I seem to recall you were also trying to match your mash run-off volume with your sparge volume (or was that Kai)?

That's made an efficiency improvement and produced consistent efficiency for me as well. If my pre-boil target is 7 gallons, I'll calculate to hit 3.5 in the mash run-off and 3.5 for the sparge. This usually means I'll mash with ~5 gallons of water, but rather than dictating mash volume by qt/lb, I dictate it by expected run off, which for an average ~1.050 batch winds up being ~1.7-2.0 qt/lb. Plus I know I can measure 5.0 gallons a little more accurately than, say, 4.652 if that's what a fixed qt/lb ratio tells me.

Of course, it doesn't always work because of different grain moisture levels and other factors (how long I'm willing to drain the MLT versus accepted MLT loss, etc.) that affect mash volume versus mash runoff volume, but I can easily adjust the sparge volume if I need to.

Denny · 01-10-2013, 08:39 PM

Quote:

Originally Posted by AZ_IPA

Denny, I seem to recall you were also trying to match your mash run-off volume with your sparge volume (or was that Kai)?

I think both of us like to be in the ballpark, but I've found there's considerable leeway. If the 2 volumes are within about a gal. of each other, that's close enough. I started mashing wiht a higher ratio mainly so I didn't need to do a post mash/pre sparge water addition-what some people call a mashout, although I never held the temp long enough for a true mashout. By using a higher mash ratio, I get about 1/2 my total boil volume from the mash runoff, then just sparge with the rest of what I need for the boil. An unanticipated upside is that my efficiency went up a bit. And the higher ratio doesn't seem to alter the beer at all.

Chromebrew · 01-10-2013, 08:52 PM

I have skimmed over this thread looking for clarification on the following but didn't find it, apologies in advance if i missed it:

When batch sparging, i understand it is preferable to leave the grain bed in tact, but it seems to me that stirring and just adding an extra vorlauf cycle would increase my already lousy efficiency. Is this accurate? I saw one guy on brewing TV talk about skipping vorlauf all together because it doesn't really impact the end result. I agree that it falls out in trub anyway.

I guess my question is, if you aren't worried about vorlaufing, would it increase my efficiency to stir the whole mash in batch sparges? (I'm sparging at 170 degrees)