help!! consistently low OG

[pdbutts]

The easiest way to find your actual efficiency is to plug the recipe into Beersmith. Enter in your measured OG and it will calculate your efficiency based on the grain bill and batch size of your recipe.

[cheezycow]

I have been assuming my efficiency is 70%. So lets say, I assume my efficiency is 65%, to keep my OG the same, I have to increase the grain and keep everything else the same? How do I actually find my true efficiency?

short answer to determine your efficiency is to divide your measured gravity "points" by the intended gravity ie

say you have a recipe that at 1.080 and you get 1.060...60/80=0.75 or 75%(your efficiency)

[BrewerAdam]

I have been assuming my efficiency is 70%. So lets say, I assume my efficiency is 65%, to keep my OG the same, I have to increase the grain and keep everything else the same? How do I actually find my true efficiency?

short answer to determine your efficiency is to divide your measured gravity "points" by the intended gravity ie

say you have a recipe that at 1.080 and you get 1.060...60/80=0.75 or 75%(your efficiency)

Thats not right is it? The reason I say that is because if I have a recipe that is at 1.080 and I hit 1.080 I dont have 100% efficiency. Each recipe should have the efficiency listed with it. If your OG is different from what the recipe says, then your efficiency is different from what the recipe says.

Here is John Palmer on calculating efficiency: http://www.howtobrew.com/section2/chapter12-5.html

[ajdelange]

To find your true efficiency you do the following
1. Measure the volume and temperature of the wort (assuming that it is at this point that you wish to know the efficiency).
2. Correct the volume to room temperature
3. Meaure the specific gravity of the wort.
4. Multiply that by 0.998203 to get the density of the wort.
5. Multiply that by the volume of the wort to get the weight of the wort.
6. Convert the specific gravity to the equivalent °P. ( °P = -616.868 + 1111.14*SG -630.272*SG*SG + 135.997*SG*SG*SG)
7. Multiply the weight of the wort by °P/100. That is the weight of the extract
8. Divide by the total weight of the grain you mashed and multiply by 100.

A commercial brewery will get numbers in the high 70's. A home brewer does well if he gets numbers in the high 60's or low 70's.

This method gives you the pounds of extract per pound of grain - about as basic as you can get. Homebrewers typically complicate the process by assigning a "points per pound per gallon " number to each malt, working out the pounds per gallon for each malt, multiplying by ppppg and accumulating the points. They then compare that to the points from the SG reading for the wort. They call efficeincy 100*points_measured/points_calculated.

[BrewerAdam]

I also meant to add that using a program like Beersmith, you can also calculate your efficiency pretty easy. It does all of the hard math for you.

[cheezycow]

Thats not right is it? The reason I say that is because if I have a recipe that is at 1.080 and I hit 1.080 I dont have 100% efficiency. Each recipe should have the efficiency listed with it. If your OG is different from what the recipe says, then your efficiency is different from what the recipe says.

Here is John Palmer on calculating efficiency: http://www.howtobrew.com/section2/chapter12-5.html

I speak of Extraction efficiency...not overall efficiency. I agree with ajdelange's method.Also I agree Beersmith and/or other software works easy to determine said numbers.

[BrewerAdam]

Thats not right is it? The reason I say that is because if I have a recipe that is at 1.080 and I hit 1.080 I dont have 100% efficiency. Each recipe should have the efficiency listed with it. If your OG is different from what the recipe says, then your efficiency is different from what the recipe says.

Here is John Palmer on calculating efficiency: http://www.howtobrew.com/section2/chapter12-5.html

I speak of Extraction efficiency...not overall efficiency. I agree with ajdelange's method.Also I agree Beersmith and/or other software works easy to determine said numbers.

Im sorry to come off sounding like an ass and I may be missing something, but what you are calling "Extraction Efficiency" (a.) has nothing to do with brewhouse efficiency, (b.) really doesn't mean anything. What exactly does knowing the percentage of how far off you are from the recipe tell you?

For example if I have a recipe that has an og of 1.050 at 75% brewhouse efficiency and I hit 1.045 then I have a brewhouse efficiency of about 65%. This tells me that I need to either work on my process to get to 75% brewhouse efficiency or plan for 65% next time which will increase my grain bill so I hit 1.050.

If I use your "Extraction Efficiency" I would do 45/50 and get .90 or 90%. What does this tell me. That I got 90% of what I was shooting to get? What exactly am I supposed to do now that I know that I got 90% of what I was shooting to get?

The reason I am responding to this in this manner is not to put you down, but to try and understand what you are talking about here. To me this is miss information and is not good for beginning brewers that may not understand what efficiency is or how to calculate it.

Thanks,
Adam

[cheezycow]

I understand where our differences are.I failed to recognize the desire was to know brewhouse eff. My initial reply was in regards to the original post. The numbers are off for each brew. It has been established that everything but thermometers seem to be accurate. So that leaves us with a few options. Temp of mash being one,i.e. wort with higher/lower attenuation. This is where I suggested to determine how well the extraction eff. was.(possibly help determine if problem is a bi-product of the mash) Next option is over sparging and or the evap rate during boil. The OP is using a recipe with assumed 75% eff. Without knowing what OP's personal brewhouse eff is, we cannot assume they have the same eff. I agree with you Palmer's calculations are excellent. For the OP to establish their eff. and rule out any possible system issues is what is needed to therefore scale the recipe to meet the recipe numbers.