Using Refractometer

I purchased a refractometer for gravity readings. I have read both pro and con about using them for brewing situations. Have a few questions:

1. Can you measure both OG & FG accurately? I've read that FG readings can be skewed because of alcohol content.

2. Where is a good cross reference scale to compare brix to gravity?

3. Any other advise when using a refractometer and brewing?

Thank you very much.

1.) I just started using one too, but I'm not aware of anything that will calculate FG to account for alcohol. Your best best is to use a hydrometer.

2.) I use this calculator on my phone: http://www.brewheads.com/brixsg.php

3.) Get your self a gallon of distilled water for calibration. If brewing out in the cold, keep the refractometer inside. If the refractometer gets too cold, your values will be very skewed.

Northern Brewer has a good calculator:

http://www.northernbrewer.com/refractometer-calculator

This questin pops up a lot, and you'll likely get some different inputs on it, but I have tested several batches, and found that a refractometer is useless for FG. Sure, it'll get close, but close isn't good enough for me.

That being said, a refractometer is an incredible tool, and saves you a lot of time on brew day. I wouldn't want to be without mine.

To get accurate final gravity readings, go to your LHBS and buy one of these

I use my refractometer for the hot side (to check conversion after mashing, through checking OG after the boil), and the hydrometer that came with my kit to check FG after fermentation.....thus avoiding the whole issue of doing conversions with the refractometer.

williamnave said:

This questin pops up a lot, and you'll likely get some different inputs on it, but I have tested several batches, and found that a refractometer is useless for FG. Sure, it'll get close, but close isn't good enough for me.

That being said, a refractometer is an incredible tool, and saves you a lot of time on brew day. I wouldn't want to be without mine.

To get accurate final gravity readings, go to your LHBS and buy one of these

Click to expand...

Never saw one of those before; that is brilliant!

rico567 said:

Never saw one of those before; that is brilliant!

Click to expand...

Makes reading the thing sooooo easy. I paid 20 bucks for mine at the LHBS and I love it. And that f'er is ACCURATE.

williamnave said:

Makes reading the thing sooooo easy. I paid 20 bucks for mine at the LHBS and I love it. And that f'er is ACCURATE.

Click to expand...

I have read a number of threads/posts that have been down on the use of a refract and questions as to its accuracy so it is good to read that there is at least one other person that has had success using a refract. I regularly double-check the accuracy of my refract against hydrometer and it always syncs up, yes even with respect to FG. The SG refracs are very accurate and the conversions are always spot on with respect to FG ABV and ABW.

I have one of the cheap refractometers I got on eBay, and it seems completely accurate. It reads zero with distilled water, and its readings are right on the money for the recipes I'm using.

Sean Terrill was recently on Basic Brewing where he discussed his efforts to create an improved FG correction formula for refractometers. His formula seems to be a marked improvement but there's still loads of caveats. Have a listen.