Refractomer

[czubak]

My refract is never that accurate (to me) and I am unsure I really trust it's readings. It seems to vary a lot if I take a few readings back to back to back. Then again it's just homebrew. I should borrow a couple and see if I am just high. I have calibrated it with distilled and the adjustments screw bottoms out before it gets to 0.000.

I think my ex got mine from NB before you could get a refract for $20-30 anywhere. It is ATC, but that is all I know. I assumed since it was through NB it was just overpriced, but the same as the $20 pieces.

[UndeadFred]

When I finally ran myself out of pipets I started to have the same problem with mine. I thought it broke. I will note that this might not be your issue but I figured I should mention it.

The small drop used on the slide, if used hot (like 140F or above) will rapidly evaporate. Gravity starts to go up almost instantaneously, based on the timing of adding to the slide the readings were all different! Once I read up on the internet about this, I started to close the slide as quickly as I could when using a spoon to draw the drop.. it helps.. but using a dropper/pipet is better because it traps the moisture in the bulb. What I did up until then is the correct way, I took a few drops and swirled them around for 30-60 seconds in the inverted pipet until they cooled down to almost room temperature and then put it on the slide. (I have 100 more pipets coming from China and they will probably beat me to my next brew at the rate my free weekends look).

In general though it's not nearly as accurate (reported to be +/- 10% but I find mine to be better, maybe +/- 5%, always average a few readings) as drawing a sample, chilling, measuring with a hydrometer, it's enough in the ballpark for me. It's nice for tweaking on the hot side, verifying that your mash is in the ballpark, etc. (When mine wasn't I drew a sample and confirmed I had a problem... my Corona mill crush adjustment came loose and half of the grains didn't get properly crushed.. I fixed it--calculated out how much more to add to the mash and did another 60 minutes.. beer turned out fine.. it's for stuff like that I love the refractometer...) I couldn't live without mine, but I'm a sloppy brewer compared to you guys who calculate everything in advance out with BeerSmith. I usually don't.

I guess if you have not ruled out what I mentioned above, try a couple of room temperature samples of something.. even sugar water, compare it to the hydrometer. See if they are consistent. If they are then it is technique.

If you really want to get the most out of it (if you are a perfectionist) then, you can make a correction factor for them.. here is a good reference on how to do this. It also explains the limitations of these devices pretty well.

http://www.brewersfriend.com/2013/04/24 ... e-brewing/

Fred


Fred

[whitedj]

Mix up a sugar water solution. Brix is really to measure the sugar content.
When I did this I discovered there was a thin film on the lens. Readings stabilized after a couple trys.

Also note with a small sample size, a small amount of water becomes significant. I usually try to rinse everything with the same sample 2-3x before taking a reading

[tony b]

Excellent suggestion. I sometimes take 2 or 3 readings to see if I'm getting consistent results.

[daryl]

Any suggestions on which refractometer to use?

[karl]

There used to be a big difference between the cheap (less than $50) models and the better (greater than $70) models. But, this is not likely to be true anymore. The governing factor was the material that the prism was made from. Today, I'd seek out the opinion of an expert before buying and be willing to spend a little extra to get a good prism. Perhaps Larry's Homebrew Supply in Washington state?

Sent from my A0001 using Tapatalk

[andrewmaixner]

If you make mostly wine/mead, get a brix version. If you make mostly beer, get a maltose-calibrated SG version.
Just make sure that you remember that on a maltose-calibrated SG scale, a sucrose/fructose/glucose "SG" measurement will be incorrect. The different sugars have a different refraction index. That "gotcha" had me really confused once, and I decided to only use hydrometers for non-beer from then on instead of goofing with a calculation.

[wyzzyrdd]

I bought a nice Brix refractometer (about $75) when I started making wine 8 years ago. It works great for wine and mead. I do use it to spot check hot wort, but I really rely on a hydrometer for accurate readings when the wort has been chilled.

[UndeadFred]

Unless you want to spend real money (like $500) on a professional digital one, my personal opinion is to get a BRIX ONLY scale ATC one from Amazon and use it as a handy tool, understanding the limitations of the device, especially in beer making. The SG markings on most of the cheap ones are wrong anyway and hard to read. Once you start forcing yourself to do the math, you'll figure out how to correct your cheap one to be "pretty good" and you will find it quite handy. The lazy man's way of doing this is to use Brewer's Friend on the computer or the free Android app.. the correction tools in that are very much good enough.

I still do hydrometer readings on post-fermented products (beer/wine/mead) and usually do post chiller on the wort, but not always. I am a sloppy brewer compared to a lot of your guys and ... eh... does it matter to me if I'm at 6.7% or 6.5%? No.. not really. I can also guess that the refractometer reading was off a little if I get too much or too little apparent attenuation from strains I am familiar with. I'm more careful, I suppose, on a new strain. I can then guesstimate a correction that way too, if it really matters.

Fred