Let's Talk about Efficiency

[Buttwidget]

So, I see a lot of people throwing around "efficiency" numbers, but I want to be sure that everyone is talking about the same thing before I start thinking about the numbers I'm getting and contrasting them against what others get.

First off, I'm using Kai "Braukaiser" Troester's awesome spreadsheet to do my efficiciency calculations found here:

http://braukaiser.com/documents/efficiency_calculator.xls

So, I see conversion efficiency, efficiency into kettle, lauter efficiency and efficiency into fermenter. What are people talking about when the talk about efficiency (particularly in the batch vs. fly sparging arguments)? I am thinking that they usually are talking about conversion efficiency.

I also remember reading something about extremely high efficiencies possibly having a detrimental effect on the end product, but for the life of me, I can't remember what it was. Any thoughts?

Thanks all,

~widget

[EagleDude]

I think the "efficiency" you should be worried about is the Lautering efficiency, which includes conversion. Basically, lautering efficiency is just a combination of how well you converted all your grains to fermentable sugars AND how well you were able to rinse those sugars into your boil kettle. Your efficiency would be the ratio of how much sugars were theoretically possible to convert during the mash and how much sugars you actually ended up with in the boil kettle.

On the homebrew scale, super high efficiency is usually paired with over rinsing of grains, increasing PH of mash due to untreated fly sparge water, and the end result of extracting unwanted tannins from the grains. In general, make sure to stop extracting wort once the specific gravity reaches 1.015 to 1.010. Anything liquid sparged below those gravities usually have high levels of tannins (often due to raising ph as you fly sparge). The worry about ph is mainly for fly sparging and batch sparging doesn't have these issues (some argue that batch sparging is much less efficient ... others dissagree).

Some of the other efficiencies mentioned in the original post simply refer to loss of liquid due to transfers (trub at bottom of boil kettle, fermenter, etc). You will be able to figure out your volume loss at each of these stages once you get used to your system and adjust batch sized up accordingly.


Hope this helps a bit.

[ajdelange]

Efficiency is simply the amount of extract obtained divided by the amount of grain it takes to produce it (and multiplied by 100 to express it as a percentage). Thus one can calculate an efficiency at any one or several points in the process. I like to do it for the kettle wort (tells me how good mash/sparge was) and in the keg when I'm finished (picks up losses hung up on hops, spillages, boil over, wort left in chiller etc.).

Unfortunately, home brewers like to confuse themselves and complicate things by refusing to use the Plato scale and by insisting on computing efficiency relative to laboratory extract (which is most often a number they get from a spreadsheet or book rather than the actual laboratory extract for the malt they are using).

I also remember reading something about extremely high efficiencies possibly having a detrimental effect on the end product, but for the life of me, I can't remember what it was. Any thoughts?

I once opined that in commercial operations where money is the driver every ounce of extract is wanted and wondered if one couldn't make a better beer if he didn't go for every last bit. The idea of leaching tannins has been mentioned. Leaching tannnins is a minus if quick turnaround is wanted but if the beer can be lagered most will complex and drop out. It has been suggested that those that may contribute to long term stability.

[Cliff]

My position is that Efficiency is for the birds.
Who needs it? Grain is cheap. I mean it is dirt cheap. Buy a few more pounds of grain and Don't Worry Be Happy.

Efficiency is for a hand full of classes of brewer:
1.) The commercial brew-master who has to squeeze every possible tenth of a penny from every single grain because his masters are holding his feet to the fire for costs.
2.) The hobby brewer who was too cheap to buy a large enough Mash Tun
3.) The unfortunate SOB who is so poor that he finds his grain bill to be a burden
4.) The hobby brewer who is too cheap to buy a few extra pounds of grain
5.) The hobby brewer who just enjoys chasing efficiency numbers because the process and tracking the result pleases him. Lets face it: Some guys really dig the technical side of the hobby (and it is a hobby it's not supposed to make sense).

If one doesn't fall into one of the above: Buy a few more pounds of grain and Don't Worry, Beeeee Happy~!!

[TimmyR]

I use BeerSmith and really like how it clearly give you 2 numbers for efficiency as described by AJ.

- Mash efficiency which tells me how much extract I pulled from my grain.
- Total efficiency which accounts for what I left behind in my equipment.

I do not worry too much about how high my efficiency is from batch to batch except that the number is about the same. On my system, I fly sparge with an AutoSparge from a Blichmann 20 gal Boilermaker to a Blichmann 20 gal Boilermaker. My mash efficiency seems to have settled around 86% and my system efficiency around 71%. I check my sparge gravity and my last 3 batches it was above 1.012. On a 10 gallon batch (as measured into the keg) I plan to leave around 2 gallons behind in the kettle, hopback, chiller and hoses. I plan to leave about 1 gallon behind in the fermenters (2 BetterBottles).

I'd be happy with a lower mash or overall efficiency as long as it was consistent, but my current system set-up seems to be working just fine for me.

[Ironman]

I think the only important thing is predictability. If you know your efficiency you can brew a recipe taking your efficiency into account and have a good chance of getting the correct gravity and ibus. I don't see any reason to worry unless your efficiency is absurdly low. That would be a sign that you aren't doing something right. One of my brew buddies helped a guy troubleshoot his low efficiency. It turned out the guy wasn't crushing his grain.

[Tygo]

I think the only important thing is predictability.

Yep, yep. Couldn't agree more. As long as you're consistent with your practices and measurements your efficiency numbers will tell you what you're going to get out of the grain on your system.

[Cliff]

I don't care about predictability either.

I change things in my brews on the fly and don't bother to make a record. More of this, some of that, different hops, "Oh gee I think I'll decoct today", "Oh Yeah I got some oats left," Hmmm I'm in a Cara red kind of mood," "Hmmm that smells good," "ohh that water was a tad hot - - oh well - - it'll have a little more mouth feel and maltiness - - COOL~!!" That pretty much describes my brewing style
I don't care that things come out the same as before, it is not relevant to me, I'm happy with the surprise.