efficinecy calculations and recipe alterations...

[wworker]

Hey there, I brewed a beer recipe last night and the OG came out a full point too high. I plugged the numbers in beersmith and it seems that my higher numbers came from better efficiency.

So, beersmith is awesome for stuff like that, but I wouldn't mind knowing how to calculate it myself. Also, if I have to scale up/down on my grain, do the percentages directly equal each other? What I mean is, if the recipe calls for 70% efficiency and I am brewing at 80% efficincy, do I scale my grain down 10%?

So, is there a holy grail of math formulas that I can peruse? I have beersmith, but I am very new to it, is there a tool in there that would help me that I am not seeing?

BTW, I brewed the Centennial blonde ale and it was supposed to be a 4% quaffer and now it will be about 5.5 if it ferments all the way out....

Thanks!!

 

[smizak]

Every grain has a theoretical ppg contribution, called potential. Briess 2-row is around 1.037, meaning it will contribute 37 gravity points per lb per gallon at 100% efficiency.

To calculate, add all of the gravity points of your grain bill and divide it by your final boil volume. This is the theoretical 100%-efficiency point total. Divide the points of your measured OG (ex. 62 for a 1.062 hydrometer reading) by that number and multiple by 100. That's your efficiency post boil. To calculate brewhouse efficiency, use the volume of beer that you actually got into kegs or bottles.

 

[Banjoman76]

A calculator that I use. I hope this helps.

http://www.brewersfriend.com/brewhouse-efficiency/

 

[wworker]

Thanks yall!

 

[weirdboy]

EDIT: whoops I guess you mean you were off by 10%.

If this is the first time you've brewed on the system, or at least that recipe, I would reduce the base malt by around 5% and see where you land on the next batch.

What I have seen some people do before is overcompensate when their efficiency on a particular batch was anomalous either due to a miscalculation (e.g. measured the volume wrong) or some other issue cropped up that they could not reproduce. So they end up overshooting and undershooting their target OG on every batch instead of just sticking to it so they can actually dial it in correctly.

 

[jfr1111]

Interesting weirdboy, this is the thing that puzzles me the most about all-grain: how do people get their efficiency initially. I'm looking at BIAB and I have conflicting reports of brewers getting as low as 55-65% on a constant basis and others getting 80%+ on approximately the same setup. I get that it's a "know your equipment and process" issue, but what would be the most optimal (ie. cheapest, fastest, easiest) way of knowing your "true", if there is such a thing as this for BIAB homebrewers, efficiency.

I was thinking about doing 2 or 3 small batches (3 gal or less) of something dead simple, yet tasty, like a blonde, cream ale or bitter, calculate my efficiency for all three identical (or near identical) brews and then modify my future recipes using this number. Because right now, when I look at stuff I want to make down the line that call for a somewhat hefty grain bill or high ABV for the style, I don't want to over or undershoot and end up with a pissy belgian or a porter that feels like used motor oil.

 

[smizak]

this is the thing that puzzles me the most about all-grain: how do people get their efficiency initially.

Unfortunately, you don't. You have to do a few batches, keep your process consistent, then go from there. There's too many variables to try and lock it in on first go. I suggest that you get your own mill, all else the same, grain crush seems to have the greatest effect on efficiency.

 

[jfr1111]

What would be a good grain crush for efficiency ? Is there a number or something I can request ? Noobish I know, but I really can't justify a mill right now, or probably ever since I brew in a spare bedroom

 

[smizak]

I thought the same, till I was dealing with the maddeningly different crushes from different stores. Unless your LHBS is on top of their mill and checks the gap regularly, it's going to be hard to nail your efficiency down. I just asked everyone in my family one year for Northern Brewer gift certificates for Christmas and bought a Barley Crusher. Love it, great mill.

Three years and dozens of batches and my efficiency still drifts from 80-85%. My Tripel got 87% efficiency, my last English IPA, 80%. Same amount of grain, same sparging rates. What should be understood is that your OG can be manipulated if you know your pre-boil gravity. You can basically measure your efficiency before you start the boil. If it's low, plan to boil longer and have a little less beer in the end, or add some DME to make up the difference. If it's too high, boil less, or in my case, dilute with some distilled water to hit the volume that will give me my target gravity.

FWIW, my mill is gapped at 0.035". When milling wheat or rye, I first pass it through the mill at that setting, then cinch it as close as it goes and run it through again.

 

[jfr1111]

LHBS sells a lot of 25kg packs and bulk orders and is the only one in the city, at least to my knowledge, to do so. So even in the advent that she is not milling for max efficiency (wich is more than probable) at least the grain crush will probably be semi-consistant from one batch to the other.

I also plan to buy 10kg bags of pale malt a shot and then 2 kilos (or even just 500 grams) or so of the most important speciality grains. I'm not much of an "experimental" guy: I like dry stout, session english ales and stuff like that. So 80% of my grain bill or more will always have the same crush (except for dry stouts, but you usually have flaked and roasted* wich are not crushed in the traditionnal sense, if I remember right). I also do not plan on brewing huge, complicated beers and have read that it's easier to shoot for good efficiency if you do not go for high SG brews.

But I'll just keep an eye open for a cheap corona style-mill nonetheless.

* I have read that he way to go is to turn it almost into powder. Almost.

 

[ThinkinDavid]

Has anyone recommended Ray Daniels Designing Great Beers? It teaches you how to formulate your own recipes and gives you all the equations and formulas so you can do it without a computer (except a calculator).