Riddle me this...

[briggssteel]

I brewed a brown ale today that I expected to get 75% efficiency on and to have an OG of 1.055. I'd plugged in all of my grains and brewing info into a brewing calculator. I run my second runnings in with my first runnings for a preboil volume of 7 gallons, take a sample, cool it to about 70. I take the reading with my hydrometer and my preboil gravity is 1.056 and my efficiency is 87%. Ok, so my efficiency was higher than I expected it to be for some reason and I figure my beer will finish in the mid 1.060's. Oh well. I'll fix it next batch. I boil my beer down to 5.8 gallons (overdid it a bit and meant to hit 6 gallons.). I pull a sample out of my pot as it's chilling, cool my sample to 70-72, drop in my hydrometer aaaaaaaand..... 1.054.

Now, this clearly makes no sense that my original gravity would be 2 points less than my preboil gravity. It should obviously be in the 1.060's. I believe that my post boil gravity was the correct one (although maybe I just want to believe it is.) My conundrum is that I have no idea how it happened. It makes no sense. The only thing that I can think of is that I when I ran my second runnings into my first runnings I didn't stir them together. Maybe I pulled from a more concentrated area or something. Any ideas as to why this may have happened would help with my sanity grestly.

 

[jfk69]

Have you calibrated your hydrometer AND did you adjust for temperature on all the samples? Hydros are usually calibrated for 60 degrees.

 

[briggssteel]

When I read water it's 1.002 so it's 2 points off.

 

[stevehardt]

I would guess is that you didn't have the worth mixed well enough bad you drew your sample
from a lighter pocket

 

[beergolf]

..001 off and you are worrying about it.

You probably didnnot mix the pre boil wort enough to get an accurate reading. You were right on with the OG, so don't worry about it.

 

[briggssteel]

No no. I'm not worried about my original gravity. I was happy because it's what I intended for an OG. 1 point off is certainly good enough for me. I was just trying to figure out why my preboil gravity read so high. Like most of you are saying I must not have mixed the runnings together well enough.