16 replies to this topic

[djinkc]

Does anyone have a rule of thumb they follow for this? I've tried brewing a few lower gravity beers lately and have overshot anticipated gravity by a lot. Today was supposed to be 1.036 (anticipating 80%), I got 1.041 and left a half gallon in the kettle because I overshot my volume too.And I mashed low and pitched a huge amount of slurry - so it will probably attenuate like crazy too. I may have to go back to extract to get something under 4%............Get me in the 1.050 - 1.065 range and I'm usually pretty close if not dead on...

[MtnBrewer]

Let's see if I understand this. You're complaining because your efficiency is too high? Maybe try no-sparge on your lower gravity session beers.

[djinkc]

Let's see if I understand this. You're complaining because your efficiency is too high? Maybe try no-sparge on your lower gravity session beers.

That ain't gonna happen around here. Just wondering if someone had figured it out based on what they get for a frequently brewed gravity beer on their system.for example1.040/83%1.050/75%1.060/70%1.070/63%I doubt it's a linear relationship, probably exponential. I figure I can probably brew a 2% beer with no grain Anyway, backtracking I had to hit around 95% but it was a tiny grainbill. There's just no way I can get myself to plug in that number, maybe eventually......

[JReigle]

That ain't gonna happen around here. Just wondering if someone had figured it out based on what they get for a frequently brewed gravity beer on their system.for example1.040/83%1.050/75%1.060/70%1.070/63%I doubt it's a linear relationship, probably exponential. I figure I can probably brew a 2% beer with no grain Anyway, backtracking I had to hit around 95% but it was a tiny grainbill. There's just no way I can get myself to plug in that number, maybe eventually......

I put this together and had posted this to a different forum a few months ago. Here's how it roughly maps out for me:1.040-1.050 = 90%1.050-1.060 = 85%1.060-1.070 = 80%1.070-1.080 = 75%1.080-1.090 = 70%1.090-1.100 = 65%

[djinkc]

I put this together and had posted this to a different forum a few months ago. Here's how it roughly maps out for me:1.040-1.050 = 90%1.050-1.060 = 85%1.060-1.070 = 80%1.070-1.080 = 75%1.080-1.090 = 70%1.090-1.100 = 65%

That's cool, thanks. I am a little surprised though, that looks like a straight line relationship. But I guess everybody's setup is going to react a bit different.Batch or Fly?

[JReigle]

That's cool, thanks. I am a little surprised though, that looks like a straight line relationship. But I guess everybody's setup is going to react a bit different.Batch or Fly?

Should've mentioned that, I batch sparge. Definitely not a perfect calculation, but at least I can use this to compensate when I brew something intending 1.045 and not have it turn out 1.058

[djinkc]

Should've mentioned that, I batch sparge. Definitely not a perfect calculation, but at least I can use this to compensate when I brew something intending 1.045 and not have it turn out 1.058

Now that would screw things up - 13 points I was just wondering. I switched to fly a while back, that might make a difference. Today didn't really matter, I had enough hops in the kettle to handle a few more points. Never batch sparged with this small of a grainbill so I really don't have a point of reference.

[MolBasser]

A............Nevermind.:)BrewBasser

[djinkc]

A............Nevermind.:)BrewBasser

That's OK, you're still learning It would be cool if you asked some guys at work tomorrow though

[dmtaylor]

I have found that OG (ignoring the preceding 1.0) plus efficiency is almost a constant, especially at higher gravity. This makes some assumptions that you are single batch sparging, always crushing to the same extent, doing the same sort of mash every time, etc. Here is a table straight off of my spreadsheet, based on more than 30 real batches:OG Eff Total1.045 87 1321.050 85 1351.055 83 1381.060 80 1401.065 77 1421.070 73 1431.075 69 1441.080 64 1441.085 59 144Then I changed my crush and my efficiency shot up another 5 to 10 points, so I'll have to make a new curve for future batches. But if you are consistent, your efficiency will be VERY predictable using this method, within a couple of points.

[Kansan]

Man, I am glad I am seeing these results with others too. A few people in our club have talked about this. It seems that every brewer has that "range" were all is right and promash or beersmith are spot on-- then there is a drift... Assuming all the elements stay the same... makes me wonder....

[drewseslu]

That's OK, you're still learning It would be cool if you asked some guys at work tomorrow though

He probably has a Siemens' inline densitometer/totalizer, anyway...

[CoastieSteve]

Are you sure it's not just your volume measurement? I batch sparge and the mis-measuring my volumes contributed to the greatest "changes" in my efficiencies. I found 3 things that really seemed to impact efficiency results and I'm now pretty consistently getting 72% efficiency for my brewhouse efficiency (batch sparge) for a wide range of OG's: 1. Differences in volumes of wort at the time of measurement 2. Closing the gap on my mill3. Stirring more at liquid additions

[BrewerGeorge]

It has to do with the higher ratio of water:grain for the lower gravity beers. Assuming the same amount of water to get to a consistent boil volume, each little grain gets more "contact" with water.

[cbbrown40]

Pretty amazing I guess I'll have to go back into my records and compare

[Jimmy James]

It has to do with the higher ratio of water:grain for the lower gravity beers. Assuming the same amount of water to get to a consistent boil volume, each little grain gets more "contact" with water.

What George said. I also think larger grain bills benefit from a mash-out and higher sparge temps to try to minimize the drop in efficiency a little. The sugars in the mash will have better solubility at higher temps and I find my sparge flows better. You might be able to drop the efficiency on those light beers DJ if you use cold water for the sparge

[Deerslyr]

Does anyone have a rule of thumb they follow for this? I've tried brewing a few lower gravity beers lately and have overshot anticipated gravity by a lot. Today was supposed to be 1.036 (anticipating 80%), I got 1.041 and left a half gallon in the kettle because I overshot my volume too.And I mashed low and pitched a huge amount of slurry - so it will probably attenuate like crazy too. I may have to go back to extract to get something under 4%............Get me in the 1.050 - 1.065 range and I'm usually pretty close if not dead on...

Dang, I just about had the same problem yesterday. Afterwards, I realized that I never adjusted my "efficiency setting" in BeerSmith after the last batch I did. But after fiddling with the numbers last night, I can safely adjust my efficiency to around 78%, which gave me the OG for the volume I collected in the fermenter. From here on out, the program should recognize that number and I'll require LESS grains to brew a batch in the 1.04ish range.Are you using any software?