When to measure OG?

[Lazer_Lad]

I have not found a lot of information on when the best time to measure OG. I assume it should be after the boil so that the final volume is right, but I have seen some people say they measure right after finishing the wort? When do you measure your OG? Also, if it is right after the boil, how do you cool the sample down quickly to measure the gravity?

 

[balrog]

I have not found a lot of information on when the best time to measure OG. I assume it should be after the boil so that the final volume is right, but I have seen some people say they measure right after finishing the wort? When do you measure your OG? Also, if it is right after the boil, how do you cool the sample down quickly to measure the gravity?

I finish the boil, dump it into the fermenter, carry it from the "BrewHouse" (to the unaided eye, it appears to be my garage) to the kitchen (side note: only brew when She Who Must Be Obeyed is out) and take a hydrometer sample at that time, pitch the yeast, carry down to the basement fermentation chamber, clean up, and measure the sample taken. Just one person's procedure.

 

[bailey mountain brewer]

You need to cool the wort down before pitching yeast, so take your OG at that point, once wort is cooled and before pitching yeast. Depending on your setup, and equipment, that will determine the easiest way to achieve that.

 

[FloppyKnockers]

I take a sample as it's being transferred to the fermenter.

 

[hotbeer]

I tend to take my OG from a sample just before I pitch the yeast. You can do it anytime after the boil is over and it's cooled down to the proper temp for whatever you are measuring the SG with. Many hydrometers sold for beer are calibrated to 68°F (about 20°C).

Waiting till just before you pitch usually insures that you have added any other stuff to your wort that might affect it's OG. Such as make up water if you want to adjust the current SG lower or get the amount to a certain volume.

 

[mac_1103]

I take a sample at the end of the boil and stick it in an ice bath to chill. Only takes a couple of minutes. I don't want to chill 5.5 gallons of wort if the gravity is off.

 

[jerrylotto]

The reasons to measure gravity and the end of the mash is to calculate mash efficiency and approximate boil off rate and water or sugar additions for the boil. And you may need to cool your sample for accuracy. OG as used to calculate ABV should beeasured just before you pitch your yeast.

 

[balrog]

@jerrylotto is right, and I do measure (with refractometer) when I lift the BIAB bag at mash end (sounds like a Hobbit address). But I also measure all manner of things because I like data.

 

[BrewnWKopperKat]

When [how and why] do you measure

Currently, I measure SG and water volume using a refractometer

1. at the end of the mash/sparge
2. before transferring into the fermenter

to confirm the process is going as expected.

Initially, #1 was used to "dial in" recipe estimates. Currently, it's almost always a "observe, but don't react measurement". In a rare batch where measurements are 'significantly different', I will hold the wort temperature around 180F while I look for missing ingredients.

Measurements at #2 confirm the results of the boil. Occasionally I miss a sugar addition (which is an easy fix). Other than that, if the numbers are close, I don't make adjustments.

The measurements for #1 are adjusted for wort temperature.

 

[Closet Fermenter]

I like taking one at the end of the boil, using a hydrometer temperature adjustment calculator. I take another once it is in the fermenter. Tilt takes over from there.

 

[AZ Maverick]

I brew using the BIAB method.
I use a refractometer for measuring gravity at the end of the mash cycle to get my pre-boil gravity.
I also use the refractometer near the end of the boil to dial in my post-boil volume and gravity.
Then I switch to a Tilt Hydrometer to capture hourly gravity and temperature readings from the pitch (through diacetyl rest if it's a lager) all the way to finish and cold crash before kegging.

 

[Brewer Mike]

I take a sample after cooling the wort after the boil.
However, there can be significant material still in suspension then. I'll use that as a tentative OG, then leave the sample in the refrigerator over night to cold crash, and get an accurate OG reading the next morning (after letting it warm to the hydrometer calibration temp). You'd be surprised at how much might settle out, depending on your process.

 

[PashMaddle]

Refractometer after mash because of ATC and small sample size cools super quick
Both hydrometer and refractometer before pitching yeast/after cooled for OG (to compare readings)
Refractometer during fermentation because I'd rather waste a few drops than a full graduated cylinder of beer every time I check.
Hydrometer before bottling for FG because I don't trust myself to get the math right on the adjustments for alcohol...and because I get to drink the sample (mmmmm flat beer)

Edit:
Sorry I got carried away.
(It is my understanding that the answer is: ) After the boil, before you pitch yeast. This way you can account for any additions that may affect the gravity added during the boil (candi sugar, honey, molasses etc.)