Beer Forum

I have a nice new automatic temperature compensation refractometer, and I've been excited to get more control over my process by measuring the original gravity at the start of the boil. Today I made my American Stout (my Christmas stout, nothing christmassy about it except when I brew it), with a 1.068 OG on paper. I was stoked when my refractometer told me I had a 1.064 OG at the start of the boil, thinking that I'd evaporate some water in the boil and hit my OG exactly. I was very not stoked when my FG was 1.050 after the boil. (I blew my mash temp, but that's a different story.)

I don't understand what happened. I put a few drops of 150 degree wort on the refractometer, waited for a few minutes for those few drops to cool, then took my reading. What did I do wrong? This is the second beer in a row where this has happened to me.

What kind of refractometer do you have?

It is an RHB-32ATC from National Industrial Supply in Torrance, California. It's a cheap one I got from eBay. But I've seen the same model for sale at MoreBeer.

If you put a few hot drops on the glass then waited for it to cool, the drops probably evaporated a good bit thus concentrating things and giving you a false high reading. I usually dip my sample with a spoon or small metal measuring cup, let that larger sample cool for a couple of minutes, then dip from there to get a couple of drops in the refract. Then I read the refract right away.

Does it read SG or Brix...

just trying out my sherlock hat!

Jhwk wrote:Does it read SG or Brix...

just trying out my sherlock hat!

Clown!!

Put on your asshat

seanhagerty wrote:

Jhwk wrote:Does it read SG or Brix...

just trying out my sherlock hat!

Clown!!

Put on your asshat

go find an airlock - pussy

I've been drawing my sample into the pipet then setting the pipet down for 5 minutes or so. Since I only draw a few ML into the pipet, it cools very fast even though it is in a plastic container. Then I take a reading.

Linc