Refractometers

[geobeery]

I want a refractometer to use while sparging. Spent a while looking at the Amazon and Ebay options. It seems almost all the options are Chinese imports and all look quite samey aside from small differences. And looking at some of the comments I'm a bit skeptical about their general quality. Does anyone know of any reputable companies producing brewing refractometers?

I'm aware the instrument would measure Brix and there would need to be a manual calculation to SG..

 

[Spud]

I'm kind of interested in one of these myself, some of the eBay ones have both Brix SG scales. Now I know you need to calibrate these but it seems to be a simple procedure. However I too am interested if anyone's bought one and has any experience or thoughts about them.

 

[Twostage]

I've got two (long story),

From different suppliers. One came in a plastic box and has the brix scale only (same left and right as you look into it). The other came in a pouch and has brix on the left and SG on the right.

Doodle to set up (you need distilled water which you can get from halfords or tesco car section).

Doddle to use (used one this morning). Sterilise the pipette and stick it in your FV and get a small sample, put three drops on the refractometer plate and look through it. If you only have brix scale just multiply by 4 and you have an approximation of SG. Close enough for in progress checking.

Can't fault it really.

 

[Spud]

I'd read something about final gravity needing correcting, didn't really understand why. Is this right or is it just a question of taking a straight reading and thats your final gravity?

 

[Twostage]

I think the alcohol interferes with the reading. There are calculators online that do the correction,don't know how accurate they are.

I'm using mine as progress checkers using the quick multiply by four which is close enough. I've got a jam jar of star San mix and a bottle of distilled water next to the brew fridge. Takes about 30 seconds to take a reading using the supplied plastic pipette.

I think most people revert to a hydrometer for FG. But you could argue that near enough is good enough :

(Doesn't sound like me that does it ?)

 

[brisboy]

Yes, alcohol interferes with the reading but there's a great calculator on the brewer's friend website which gives you a corrected reading. I've got no hydrometer as a one drop sample for a reading makes a lot of sense when you only have one gallon of beer to start with. :)

 

[Twostage]

Current brew seemed to be slowing down so I took a hydro reading as well as the refractometer.

Refract said about 4.8%, original was 10%. Put it into the musther.net vinocalc page which calculates mid ferment SG. It calculated 1.006. Tested with hydro and it said 1.010.

Maybe my OG reading was wrong :hmm:

Anyway, I still think it is a useful device for seeing how things are going. Once it stops dropping brix (must be a joke there) and you know it's stopped you can use a hydro for confirming final gravity.

(Brew tasted nice by the way :razz:)

 

[Twostage]

Yes, alcohol interferes with the reading but there's a great calculator on the brewer's friend website which gives you a corrected reading. I've got no hydrometer as a one drop sample for a reading makes a lot of sense when you only have one gallon of beer to start with. :)

Tried the brewer's friend version of the refractometer calculation and it was spot on with my measurements.

I also did a side-by-side test of the two hydrometers and they read exactly the same. Worth pointing out that it took about a minute before they read the same. The instructions do say leave for 30 seconds and it appears you need to wait at least this. The readings went from 4.6 to 5.6 in this time.

 

[Tyro Brewer]

I was given a refractometer as a gift and have used it on my current brew. Starting SG was 1.053 measured by the refractometer and 1.050 measured with the hydrometer (for comparison).

After about 3 weeks I thought the brew must be ending soon so used the refractometer and converted the Brix to get a FG of 5 (or multiply by 4 to get 1.020).

Very frustrated as the brew, Muntons Oaked Ale, had stuck at 1.020 a week earlier (measured with a hydrometer as I couldn't get a sensible Brix reading, or so I thought!) and needed a gently stir. Using an hydrometer I got a reading at the same time of 1.009. Confused? You bet.

Did a bit of Googling and it appears that alcohol will distort the refractometer readings so the original Brix measure is correct (no fermentation at the start so scale is correct). As fermentation takes place to produce the desired alcohol the refractometer needs a conversion factor to give the correct readings.

I used this: http://http://www.northernbrewer.com/learn/resources/refractometer-calculator/ and all was OK. The final SG from the converted Brix measure was very close to the hydrometer reading.

Will I use the refractometer again? Absolutely, no need to use precious beer for the trial jar as just a few drops are needed on the instrument screen and with the calculator, I am confident in the accuracy of the refractometer.

 

[Twostage]

Yes, I quickly realised that X4 works at the start but you need a calculation once it gets going. I use the first readings to find out what the 'wort factor' is for that brew so that I can correct the later readings.