Refractometer vs. Hydrometer Pros and Cons

Hi everyone,

I recently broke my trusty hydrometer and was wondering if I should upgrade to a refractometer or not. I was wondering what the pros and cons are of a refractometer. I know all about hydrometers but not refractometers. Can I use them for FG readings? Thanks for any help!

Some will say yes, some will say no for FG. You have to do a conversion - you can't read FG without adjusting for OG. But my experience is the conversion is pretty accurate. I love the refractometer. I use way less beer, it's much cleaner, and it's much easier. I take more readings during the brewing process to see where I am because it only uses a couple of drops.

Beersmith does the conversion for you in it's refractometer tool, so it's not a hard thing to do.

Both. I use my refractometer several times through out the brew day. It is great for quick readings to make sure everything is going as planned. However, I always do an OG and FG measurement with my hydrometer too.

Refractometers are fast, simple, no need to bring down to calibrated temps. As mentioned above, they are not as great post fermentation and only a hydrometer will be accurate.
Hydrometers require calibrated temps, break easily and use more beer. They are trustworthy though, and always have a place in a brewers toolbox.

If you have the cash on hand - then yes, get one. It's vastly superior during the brewing process. You can grab tiny samples as you run wort and throughout your boil - no cool down time for your hydro.

Once I'm into fermentation - then the hydro is where I go. It gives me a sample to taste as well as FG readings without conversion.

A refractometer doesn't replace a hydrometer.

Use the refractometer for everything except the last FG reading -- use the hydrometer for that.

'Conversion factors' are not reliable.

I use both.
Just bought an ebay refratometer, with atc.
I'm keeping records of both instruments now.
Looking ahead, I think I'll still use both.

I use a refractometer for everything. I still have a hydrometer and never use it. I consider a converted FG close enough for my purposes.

Some say the refractometer is not accurate for FG readings, but my experience says Differently. Note that I haven't measured a really big beer with a refract. but my several head-to-head comparisons have always been dead on. Your results may not.

That said, you can save a ton of time by taking a very small pipette of wort and swirling the bulb in 60 degree water and taking a reading. Literally less than 1 minute. It's just way faster during the brewing process.

And if you can't, or don't, trust your refractometer for FG readings, you should still buy a hydrometer to have on hand anyway. They are cheap.

Homercidal said:

Some say the refractometer is not accurate for FG readings, but my experience says Differently. Note that I haven't measured a really big beer with a refract. but my several head-to-head comparisons have always been dead on. Your results may not.

That said, you can save a ton of time by taking a very small pipette of wort and swirling the bulb in 60 degree water and taking a reading. Literally less than 1 minute. It's just way faster during the brewing process.

And if you can't, or don't, trust your refractometer for FG readings, you should still buy a hydrometer to have on hand anyway. They are cheap.

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In my experience, the refractometer is not accurate for FG readings. It'll tell you when the beer or wine is finished, in that it will not change, but even with the conversions I haven't had it all that accurate.

I use both. The refractometer on brewday, and the hydrometer on bottling/racking day.

Using a quality refractometer kicks ass. I have three now. Two cover the range I use for brewing beer (one up to 32 brix, in .2 increments, one up to 20 brix in .1 increments, and one up to ~60 brix for mead OG). These were not cheap though. The two for beer cost me about $100 each (they all have ATC). If you're looking to be cheap, then get a few hydrometers and check them for accuracy. There are enough threads about hydrometers not reading properly to warrant checking every one of them. For me, I'm good with using the software to offset the presence of alcohol (it will throw the reading off once fermentation starts) since I can use such a tiny amount for the reading sample. I use 4 dram vials to reserve wort, and finished beer, to get my readings. That's about 1/2 ounce in each vial, so 1 ounce from each batch for the OG and FG readings. As previously noted, it's accurate enough (with the software adjustment) for an OG, and even FG, reading, for me. I give my beers enough time to be finished, so I'm just checking to see what the numbers are before putting them on tap.

I've never broken my hydrometer, and still have the one that came with my original hardware kit. It sits in a closet now, unused for many batches. Not sure if I'll ever use it again, since it does require such a large (compared to a refractometer) sample to get a reading.

Homercidal said:

And if you can't, or don't, trust your refractometer for FG readings, you should still buy a hydrometer to have on hand anyway. They are cheap.

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So I abandoned my hydrometer and used my refractometer full-time when I got it. The first four batches were spot on after 'correction factors' for FG measurements. All was well.

But the next two batches (high gravity, mid gravity) were over +0.020 off after corrections.

So either don't care about FG accuracy or keep your hydro handy.

There is a place for a hydro, but I love my refractometer! I'm still verifying my compensated FG refractometer reading with my hydro reading. So far I am gaining a comfort level with the refractometer. The calculator will get within .002 which has been consistently the case (4 batches now). SG has been within .001.

Get one on eBay for $20-30. Very happy with my purchase!

I just picked up a refractometer, and let me tell you how much easier my brew day just got! It used to be a pain - for first runnings and final runnings I'd pull out a sample and let it cool. I wouldn't know my readings until after the boil was half over and, at that point it was too late to make corrections. Corrections were noted and could be made for future batches. Now I grab a couple drops with a pipette and have an instant reading. I now take readings at every step and can make adjustments as needed on this batch.

If you go with the refractometer make sure it reads in Brix and not SG. I think the bad rap that refracts got in the past was because some manufactures released ones that only had a SG scale. It was useless for anything after start of fermentation.

rhamilton said:

A refractometer doesn't replace a hydrometer.

Use the refractometer for everything except the last FG reading -- use the hydrometer for that.

'Conversion factors' are not reliable.

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I used to think/say the same thing... until I tried Sean Terril's tool (http://seanterrill.com/2012/01/06/refractometer-calculator/). Batch after batch, it matches my hydrometer every time.

+1 Bru - that is the same site I used for my FG adjustments. The small discrepancy between the refractometer and hydrometer is usually +-.002.