Try to figure out Brewhouse Efficiency and System Calibration

[albysurfin]

Here we go sorry for the length ......
I have done about 17 all grain batches and on about my 5th batch I started using BeerSmith and just used it to store my recipes etc. I started to learn how to use it and my last 4 batches or so I have tryed to calibrate my system and tried to start to figure out my efficencies. What I found out is that my original dipstick measurements for my brewpot were off, which actually worked in my favor because I was creating enough wort. Now that I am no longer using a dipstick and using a 1 gallon measuring pitcher to measure everything exactly. I have been coming up short on my volumes by quite a bit. My brewhouse efficiency seemed to work out at 66%. I started to tweak some of the boil characteristics of my equipment. My equipment was set for 13% evaporation loss; I use a Sanke keg for my brew kettle. As I was tweaking my eveaporation it seemed like 19% worked and added .50 gallon lost to trub etc. for my last 4 recipes that came up short in volume That seemed pretty high to me. My boil is usually not that aggressive maybe the first five minutes or so until I have gotten the lowest controlled mellow boil.
So for example I brewed a Hefeweizen last night. I collected 6.2 gallons of wort and topped up to 6.87 gallons; after a one hour boil, I only had about 4.5 gallons going into primary. I added a gallon of water to get to 5.5 gallons. My Estimated Original gravity in Beer Smith was supposed to be 1.048 and I measured 1.066 original gravity after adding the gallon of water. This means I got an actual brewhouse efficiency of 90.01%? Is that possible doing the 2 step batch sparge? How does the loss of wort equate into the efficiency? Does the fact that I had so much loss to evaporation boost my brewhouse efficiency numbers and gravity or are they independent variables?

Please help I really want to get this thing sorted out!!!

Thanks for any Input you may have!!!

Brian

 

[northernlad]

Did you take the gravity preboil?
Evaporation does not effect your efficiency. If you have 6.87 gallons @ 1.06 for example, you are going to have 5 gallons @ 1.082 after the boil.
As some have said, variances in grain can give you unexpected results
as well as trusting what your HBS is weighing for you. If you ordered 10 lbs there is a chance there is more than 10 lbs and you would not know unless you verified.

 

[albysurfin]

I did not take a Pre Boil Gravity, will definitely do this next batch, also at my LHBS you weigh your own grains so I know the grain bill was what I wanted.

 

[bigjoe]

I don't think this will solve your problem, but I prefer to use a constant for evaporation. If I'm doing 5 gallons I'll boil off a gallon and a half in 75 minutes. If I did 10 gallons I boil off the same quantity. So I boil off 30% on a 5 gallon batch and 15% on a 10 gallon batch.

Just from what I read in your post it sounds like you need to get your equipment calibration inline to me. How far off was your dipstick. I would think you'd be able to take it into consideration and compensate. I just recently had to do a similar thing when I went to a keggle. evap rate was a little different and I do no sparge brewing, and in my old keggle I had to hold bakc a gallon. Small stuff really but it makes a difference.