Is it even possible?

[arborman]

So, I brewed a 12 gallon batch of Black IPA yesterday. Ive done this recipe before, and its very good.

Everything went extremely well, other then I missed my pre boil gravity by 4 points. Came it at 1.060 instead of 1.064.

in fact, things went so well that I completely forgot to get my refract sample before I put it to bed in the conical. So, I opened the side valve and pulled a small sample to take my reading...

1.060. WTF? Is this even possible?? Me thinks not, since I even boiled off nearly 1.5 gallons thru my boil. I was looking to hit 1.066-1.070.

Now, I could think I made a mistake reading, but I am nearly 100 percent sure that I read both samples correctly... But, something is not jiving.

So, is it even possible to go through a full boil and not have the gravity even change?

 

[Black Island Brewer]

Of course not, because sugar does not "go away", so to speak. I've been having a similar problem, and it was suggested that my pre-boil measurement may be to blame. I get somewhat impatient to get my reading, so I have not been cooling my pre-boil sample down (I have ATC after all, so why wait?), and since it's just a drop or two, the evaporation that occurs in that short time may be giving me higher readings. I'm going to test this out on my next brew day by drawing a hydrometer sample at the same time, and taking my refrac sample after it has cooled, and then compare it to the hydro sample.

 

[arborman]

Wow, this is just really strange then... I am almost 100% sure I checked, double checked and triple checked all the readings... Mainly because I was off on my first reading, so that was double checked.. When I saw my OG was the same as my pre boil, I triple checked!

Did a distilled water sample on the refrac today, and its sitting right at zero. This has me scratching my head..