Refractometer for FG

[BrainYYC]

Hi folks, I believe I recently read a post on here from a fellow brewer that a refractometer can be used for 2-3 days in a row to check stabilized gravity. Understanding the actual reading won’t be accurate, I’m talking about pulling a small sample and simple checking for a similar readings to indicate fermentation’s complete.

I would still measure my actual FG with my hydrometer prior to bottling.

Do I have that right?

 

[Nosybear]

Hi folks, I believe I recently read a post on here from a fellow brewer that a refractometer can be used for 2-3 days in a row to check stabilized gravity. Understanding the actual reading won’t be accurate, I’m talking about pulling a small sample and simple checking for a similar readings to indicate fermentation’s complete.

I would still measure my actual FG with my hydrometer prior to bottling.

Do I have that right?

Sounds right to me.

 

[Craigerrr]

Brain is getting antsy to bottle his Kveik fermented NEIPA!

 

[Sunfire96]

There's a refractometer calculator on this site for that exact purpose (if OG is known). That's what I use for FG readings

 

[Zambi]

Yep, you are right.
And what Sunfire says

 

[BrainYYC]

Thanks all!

 

[BOB357]

Hi folks, I believe I recently read a post on here from a fellow brewer that a refractometer can be used for 2-3 days in a row to check stabilized gravity. Understanding the actual reading won’t be accurate, I’m talking about pulling a small sample and simple checking for a similar readings to indicate fermentation’s complete.

I would still measure my actual FG with my hydrometer prior to bottling.

Do I have that right?

A refractometer is just as accurate as a hydrometer, provided it's properly calibrated and the wort correction factor, which is specific for each tool, is calculated by comparing hydrometer and refractometer readings from several worts. Once fermentation has begun and alcohol is present, the OG and current Brix readings need to be entered into a calculator to compensate for the different refractive index of the alcohol and come up with an accurate reading.
Brewers Friend has a great set of instructions and calculators for using a refractometer. You can also do as you stated and compare readings over 2 or 3 days to determine if fermentation is complete. I use my refractometer throughout the brewing process almost exclusively, and only use a hydrometer occasionally as an accuracy test for the refractometer.

 

[Steelyace]

I stopped using a hydrometer years ago now. When I switched to a refractometer I compared it to my hydrometer for many many brews and found it to always be the same. So now its easy, just a dropper full to test is all that is needed.