AG efficiency and reality

[william_shakes_beer]

OK, Let's discuss this like gentlemen and ladies.

I read lots of threads about people stressing over efficiency ( I stirred counterclockwise and gained 2 gravity points whoopee!!!) Here's how I see it. Please feel free to correct inaccuricies

We calculate expected OG at 100% effeciency based on brewing software, then adjust for our expectations and brewing history. (I use 75% because it's the software default)

However, the brewing software OG is based on an average expected yeild for an average of the target malt produced by an average maltster with an average year's grain crop.

It seems to me that there are so many variables in the expected OG that an efficiency difference of 15 points or less is more or less negligible. Am I missing something? How much variance do you tolerate in your mash before you start looking for causes in your process?

 

[Gartywood]

based on my experience 5% deviation in efficiency is normal (I see about 73-78% mash efficiency and I am happy with that). If i was hitting 60% one day and 75% the next i would be very concerned about repeatability as well as being able to brew the beer that I designed. If you want to make consistent beer (note i said consistent not consistently good because you can make consistently good beer without having consistent results) First and foremost you need predictable results which means paying attention to volumes, taking gravity readings (pre and post boil), and keeping records.

If you hit 60% all the time that's fine. if you want to increase efficiency you will want to take even more notes and change one thing at a time for a couple of brews to determine the effect.

 

[corax]

We calculate expected OG at 100% effeciency based on brewing software, then adjust for our expectations and brewing history. (I use 75% because it's the software default)

I calculate expected OG based on the potential extract for each malt, and the amount of each malt. I suspect that any brewing software worth its electrons does the same thing. The potential extract is measured by the maltster, and is actually fairly consistent and reliable. The expected efficiency I apply is usually a rough average of the actual efficiency I achieved over the last few batches.

Deviations in my mash efficiency are much more likely to be due to variations in my mashing process, not in variations or inaccuracies in potential extract numbers.

I generally target my OG to be somewhere in the middle of the appropriate range for the style, and then don't stress out too much if I'm a few points high or low.

 

[TyTanium]

Deviations in my mash efficiency are much more likely to be due to variations in my mashing process, not in variations or inaccuracies in potential extract numbers.

Agreed. And I'd add measurement error, too. Unless you have precise equipment, count on at least 2-3% measurement error.

My personal tolerance is +/-5%. Anything above or below I'll take corrective action (boil longer, add water, adjust hopping, etc).

 

[william_shakes_beer]

I calculate expected OG based on the potential extract for each malt, and the amount of each malt. I suspect that any brewing software worth its electrons does the same thing. The potential extract is measured by the maltster, and is actually fairly consistent and reliable. The expected efficiency I apply is usually a rough average of the actual efficiency I achieved over the last few batches.

Deviations in my mash efficiency are much more likely to be due to variations in my mashing process, not in variations or inaccuracies in potential extract numbers.

I generally target my OG to be somewhere in the middle of the appropriate range for the style, and then don't stress out too much if I'm a few points high or low.

Understood, agreed. However, there's got to be a diference between 1. (a 6 row grown in Iowa and malted in chicago by maltster x) and 2. ( a 6 row grown in germany and malted by maltster y) The brewing software only lists potential OG for 6 row.

 

[zachattack]

Understood, agreed. However, there's got to be a diference between 1. (a 6 row grown in Iowa and malted in chicago by maltster x) and 2. ( a 6 row grown in germany and malted by maltster y) The brewing software only lists potential OG for 6 row.

I think the variations are pretty small (and FWIW Beersmith has lots of malts listed by geography, the 6-row was a poor example), but with that being said you can always override the defaults with the actual potential of the malt you're using.

 

[huge1s]

I would think that for homebrew purposes, the difference is small enough to have little to no impact on the brewing process. Now.... I could see why a big brewing company would care about the small differences because they want their beer to taste exactly the same wherever you drink it.

I am not a super seasoned homebrewer, but one thing I learned quickly is that my garage is not a six sigma production manufacturing facility. I enjoy being precise and to a point it has improved my beer, but I also realize that I can spend a lot of time trying to be too precise. Really... if i have my process controlled to the point that the small difference between 6 row from german vs 6 row from the US has a noticeable effect on my beer... I should be competing with the big boys instead of brewing in my garage.

 

[william_shakes_beer]

I would think that for homebrew purposes, the difference is small enough to have little to no impact on the brewing process. Now.... I could see why a big brewing company would care about the small differences because they want their beer to taste exactly the same wherever you drink it.

I am not a super seasoned homebrewer, but one thing I learned quickly is that my garage is not a six sigma production manufacturing facility. I enjoy being precise and to a point it has improved my beer, but I also realize that I can spend a lot of time trying to be too precise. Really... if i have my process controlled to the point that the small difference between 6 row from german vs 6 row from the US has a noticeable effect on my beer... I should be competing with the big boys instead of brewing in my garage.

ok, you're probably right. I'll crawl back under my rock.

 

[BBL_Brewer]

A lot of good points have been brought up. Paying close attention to volumes is probably the most important thing you can do to maintain consistency. This also means you need to pay attention to temperature in relation to your volumes. Good software should take temperture into account when calculating the batch for you, but that may not be good enough if you pay no attention to temperature when you measure volumes youself. I think our own processes and how we collect/measure data cause more inconsistency with effeciency than different maltsters and grains cause. And as mentioned, you can change the default value for the gravity contribution of your grain if you run into this problem. I agree with Gartywood. 5% deviation is pretty normal even once you get your process dialed in with the same ingredients. If you're hitting your volumes right on the money evey time and your efficiency varies more than this, then there are other problems to blame other than the grain.

 

[TrubHead]

Based on limited past brewing numbers (started Feb 2012), +-2 gravity points is acceptable. More than that and have to think what happened during the process.

 

[passedpawn]

I get between 70% and 80%, depending on the OG. It's very, very repeatable if I make the same beer (I make 2 specific beers, a Rye IPA and a pilsner, a lot).

 

[huge1s]

ok, you're probably right. I'll crawl back under my rock.

sorry... I wasn't trying to be a jerk. I was just trying to say that we can only go so far to control the process as homebrewers and shouldn't worry about the parts that we cannot control or have little effect on our beer.

brew on!

 

[corax]

Understood, agreed. However, there's got to be a diference between 1. (a 6 row grown in Iowa and malted in chicago by maltster x) and 2. ( a 6 row grown in germany and malted by maltster y) The brewing software only lists potential OG for 6 row.

Then you either need new software or do the calculations yourself (it's not that hard).

 

[sonex]

for the very first brewing of any first recipe I usually will be within +-5 points. After I have data on that recipe I make efficiency corrections for that beer and expect to be within 2-3 points of my target SG and FG. Consistency is very important to me b/c if I brew a batch I don't want any surprises, I want that beer to always taste the same.