Considering buying a refractometer

Any reason not to? I like the idea of immediate gravity readings during mash and pre-boil. Anything worth worrying about for post fermentation reads?

I have been using my refractometer for about 2 years now and love it. Being able to take quick readings on a whim is great, so long as you understand that there is a percentage error associated with using them. Software like beersmith makes the corrections quick and easy. In the last few months I have become more concerned with consistency and have pulled my hydrometer out more frequently, but using it feels tedious by comparison.

There is an equation or there are excel spreadsheets you can use to calculate your SG from your OG using a brix reading on a refractometer post-fermentation. But this is one of those scenarios where I have gone back to using a hydrometer.

They are a great investment. Get one. Plus, he who dies with the most toys wins!
(Just understand the drawbacks and benefits of each of those toys while using them)

See, it's the post that's my bigger concern. I hate having to go in there and draw samples, and sometimes they can be so hard to read with foaming and whatnot. But on the other hand, I really like the idea of reading my runnings and boil. Decisions decisions.

if you write down your initial brix reading, a couple drops of your fermented beer and this webpage will tell you the final gravity:

http://www.onebeer.net/refractometer.shtml

I can't believe people still brew (especially all grain) with hydrometers. JMO.

jacksonbrown said:

See, it's the post that's my bigger concern. I hate having to go in there and draw samples, and sometimes they can be so hard to read with foaming and whatnot. But on the other hand, I really like the idea of reading my runnings and boil. Decisions decisions.

Click to expand...

Using a stir straw like a wine-thief works great for punching past foam. Hell, with the right size straw you could go right through the airlock hole (or one dedicated for such readings) and never even lift the lid if you are the type of guy who enjoys taking readings every day.

I don't think they work well with fermented beer. They are only useful for 1) mash / boil, and 2) brewers that don't care too much about the numbers.

Sometimes I wish I was #2, but it's not in my fabric.

Do a search for Wort Correction Factor for more information. Or, see this: https://www.homebrewtalk.com/wiki/index.php/Refractometer

"Beers that are very dark or have a very high starting gravity may also require a different correction factor."

Well just to be contrary, I find my refractometer pretty superfluous. I pretty much always take a hydrometer reading before kegging so I can taste as well as measure and the refractometer is always off enough for me to doubt it. I do take readings pre boil, and it is handy for that, but frankly I always hit my numbers so I find myself being irritated at my $40 device which simply confirms my process... FWIW and YMMV and WTF

Sds

They are very handy for taking quick readings of hot liquids from the mash and boil. Much easier then using a hydrometer where you will need to cool a sample to get a reading. The refractometer can give you a decent reading in a matter of seconds. But they are not super accurate. Even if the optics and ATC are working perfectly there will still be some level of user error just reading the scale. The difference between 4.2 brix and 4.6 brix is very hard to read with my human eyesight. Nothing to go crazy about but for accuracy a hydrometer is a better tool. But what they lack in accuracy they more then make up for in speed and convenience. I think it's an awesome tool for brew day. Especially for adjusting your boil gravity.

When the beer is fermenting or finished you need to use some conversions to adjust the readings for the alcohol. There are websites with calculators for this. Beersmith has a very nice adjustment tool built in. But at this step in the process the beer is cool and I find a hydrometer is the way to go.

Be aware that every source I'm aware of uses the same correction for post-fermentation gravity readings, and that it's both inaccurate and imprecise. Mathematically speaking, it isn't a complicated problem, and I think it's possible to do significantly better: http://seanterrill.com/2010/07/20/toward-a-better-refractometer-correlation/