How do you take hydrometer readings before boil and post boil?

Seems like a simple question, but brewing my first AG batch and using an aeration stone for the first time left me a few problems.

So after sparging, I'm left with ~160*F water. I've seen hydrometer correction tables go to 150, but usually nothing over that. Is there an equation you can use?

And after pouring my cooled wort into my primary, I'm left with about an inch of foam on top that can't be scooped away to be able to see my hydrometer. Aeration makes it even worse. What do you do to get around this?

I'm not incredibly concerned about my hydrometer readings, it would just be nice to get a good baseline brewhouse efficiency for future reference.

well for one, on brew day I use a refractometer. But in your case there are some things you can do.

Don't rely on calculations with hot wort. The farther it is from 60* the less accurate your calculations are going to be. As soon as all your sparge water is in the kettle, stir and take a sample. Put the sample in an ice bath. You should be able to get it down to temp before your kettle boils.

When pouring your cooled wort into the primary, pour some into your hydrometer too. Then add the o2.

Any readings over about 90 degrees are inaccurate, so cool the sample first. You can do it by putting the test jar in a pitcher of ice water or in the freezer, and it will cool in a few minutes.

Take your reading using your hydrometer in a sanitized wine thief after cooling the wort.

i just pull off a few hundred ml and toss it in the fridge... when it gets cold enough, i pull it out, let it warm up and then mix and measure..

i'll ice it down quickly if i think i might need to do something corrective.

I would be scared of putting my hydrometer in any hot liquid. Glass can easily shatter with significant temperature changes.

NRS

phenry said:

And after pouring my cooled wort into my primary, I'm left with about an inch of foam on top that can't be scooped away to be able to see my hydrometer. Aeration makes it even worse. What do you do to get around this?

Click to expand...

This leads me to believe you are dropping your hydrometer into your fermentor... If so lean toward pulling a sample and not doing it in a situation where if it broke your beer would be ruined. Plus you cannot get an accurate reading. Also during your whole AG session keep a large bowl with ice water where you can cool down samples through-out the process.

http://www.austinhomebrew.com/product_info.php?products_id=12972

AHS has a hydrometer calibrated at 155