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Brews & Views Bulletin Board Service * Brews and Views Archive 2004 * Archive through June 28, 2004 * Anyone use a refractometer? < Previous Next >

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Richard Nye
Member
Username: Yeasty_boy

Post Number: 115
Registered: 01-2004
Posted on Sunday, June 20, 2004 - 10:01 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

I just got a refractometer mostly to get quick gravity measurements before, during and after the boil. If you've used one, do you like it? Are they as accurate as a hydrometer? Are there any other practical uses?

They say you can use it on fermented beer, along with a hydromter to get the ORIGINAL GRAVITY. I tried it on my last batch (using the formula in Promash) and it was way below the actual OG.
 

Rob Beck
Member
Username: Robbeck

Post Number: 106
Registered: 03-2003
Posted on Sunday, June 20, 2004 - 10:16 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

I've heard that it is not accurate on fermented beer because the alcohol interferes with the reading.
 

Dave Witt
Intermediate Member
Username: Davew

Post Number: 400
Registered: 03-2003
Posted on Sunday, June 20, 2004 - 02:16 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

I've been using one for a couple years now. You can't beat it for getting quick readings during mash, sparge and boil. IIRC, for every 11 deg Brix, you need to knock off a point after you multiply by 4.

IE--11 deg x 4 = 44 - 1 = 1.043.

For on-the-run checks I don't worry about the one point error.
 

Bill Pierce
Moderator
Username: Billpierce

Post Number: 60
Registered: 01-2002
Posted on Sunday, June 20, 2004 - 02:50 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Richard, you have already found the best use for a refractometer, taking gravity readings during mashing, sparging and prior to the boil. It requires a tiny (less than 1 ml) sample and there is no need to cool it (the tiny volume is cooled to air temperature almost immediately). The inexpensive (under $70) refractometers do not have quite the resolution of a good hydrometer but are probably equal to the cheap ones. They are certainly plenty close enough for their intended purpose.

Refractometer readings are skewed by the presence of alcohol and must be corrected once fermentation begins. The formula (a utility is included in ProMash) for correcting the readings is quite accurate if you know the true O.G. However, trying to deduce the O.G. and correcting the readings without knowing the true O.G. is more guesswork than reality.


(Message edited by BillPierce on June 20, 2004)
 

Paul Hayslett
Junior Member
Username: Paulhayslett

Post Number: 430
Registered: 02-2002
Posted on Monday, June 21, 2004 - 03:04 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

I have a refractometer and it's a great toy. But it has one enormous drawback compared with a hydrometer -- no sample to drink afterward! There's nothing better than checking all the carboys of an evening and drinking what's in the sample jar afterward, especially if you have 5 or 6 to check.
 

Jeffrey Donovan
New Member
Username: Jdonovan

Post Number: 35
Registered: 02-2003
Posted on Monday, June 21, 2004 - 03:10 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

HUH, a different reading. I guess ProMash must be wrong.

- Jeff

(Message edited by JDonovan on June 21, 2004)
 

Dave Witt
Intermediate Member
Username: Davew

Post Number: 401
Registered: 03-2003
Posted on Monday, June 21, 2004 - 03:20 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Paul,

I agree with that. But I've never used a refractometer on fermented beer, only unfermented wort which more often than not, I don't taste anyway.
 

Richard Nye
Member
Username: Yeasty_boy

Post Number: 116
Registered: 01-2004
Posted on Monday, June 21, 2004 - 09:39 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Jeff, Promash is a great product BTW. I measured a dry stout (OG was 1.040) after it was nearly fermented out with my refractometer. Refractometer measurement on fermented wort was 4.5 brix, hydrometer measurement on same fermented wort said 1.010. Promash calculates the OG at 1.031. I know a refractometer isn't great at measureing OG of fermented wort, but what gives?
 

Jeffrey Donovan
Junior Member
Username: Jdonovan

Post Number: 36
Registered: 02-2003
Posted on Monday, June 21, 2004 - 01:01 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Well, a couple of things come to mind:

1) It's nearly impossible to determine a decimal reading for a brix refractometer (IE 4.5) where graduations are in whole units. If this is a cheapy refrac made in China I make no promises at all, you get what you pay for, most are junk.

2) The same is true for the hydrometer, if you read it just a tad off then that can make a huge differemce.

As an example, change the numbers just slightly to 5.0 brix and 1.008 on the hydro. The calc comes in at 1.0395 OG.

So, what I question in all of this, esp. when it comes to precise measurements is:

1) How accurate is your gear? What type of hydrometer and refrac. If both are budget cheapies then no promises. If middle of the road or high end then you should be getting accurate measurement.

2) How sure are you on the precision of your reading? As demonstrated, when you get this close precision is everything.

Also, have you read in detail the ProMash help on calibrating the refractometer properly and have you done so?

Lemme know,

Cheers!

- Jeff
 

Bill Pierce
Moderator
Username: Billpierce

Post Number: 63
Registered: 01-2002
Posted on Monday, June 21, 2004 - 01:07 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

I'm frequently reminded of an old saying: a man with two clocks never knows what time it is.

Brew on!
 

Richard Nye
Member
Username: Yeasty_boy

Post Number: 117
Registered: 01-2004
Posted on Tuesday, June 22, 2004 - 01:59 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

I'm with you, Bill. Once I get the refractometer dialed in I think I'll stick with it for the wort, and go with an accurate hydrometer for the beer.

Jeff,
1) I'm pretty sure the hydrometer reads between 4.3 and 4.7 (looks like 4.5 to me, but the line is a little blurred - from alcohol?)

2) I may be off by 0.001, but that's about all.

1) Refractometer is supposed to be accurate to 0.2 brix, but I have to admit, it's a Chinese model. The hydrometer also has a pretty wide range with less precision.

I have read the fine print about calibrating the refractometer and I haven't determined the brix correction factor yet, but the refractometer is auto temp corrected and reads 0.0 with water.

I'll play around with it to see if I can get better results with different samples.
 

Pacman
Member
Username: Pacman

Post Number: 161
Registered: 04-2003
Posted on Tuesday, June 22, 2004 - 02:34 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

I've had my refractometer for about 3 years now and the only time I use my hydrometer anymore is to compare readings between it and the refractometer, which I don't do very often... I have found that for reading both OG and FG the refractometer is close enough for me... For the most part, when i've compared readings between the two, they have been right on with each other... That goes for high and low gravity beers as well as light and dark beers...

I don't miss out on tasting the beer either... When I take samples to determine FG I do still take enough to taste the sample but not enough that would fill a hydrometer jar... drinking warm, uncarbed beer is fine but I save the real drinking for when i'm finished taking readings and get a nice, tall cold pint....
Damn Brewing's Fun!!!!
 

Geoff Buschur
New Member
Username: Avmech

Post Number: 1
Registered: 06-2004
Posted on Tuesday, June 22, 2004 - 12:16 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Here is a trick I figured out to read a refractometer down to the decimal. Hold the refractometer eyepiece up to the lens of a digital camera. Snap a picture and zoom in on the scale. Even if the blue line is fuzzy it becomes very clear when you zoom in and look between the hash marks. Another advantage to this is at the end of the brew session you can download the pictures and transfer the readings to your notes in ProMash.


22.2 Brix
 

Pacman
Member
Username: Pacman

Post Number: 164
Registered: 04-2003
Posted on Tuesday, June 22, 2004 - 12:38 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Sweet idea Geoff... I am going to try that tonight... I have a fairly old and cheap digital camera so hopefully it works....
Damn Brewing's Fun!!!!
 

Geoff Buschur
New Member
Username: Avmech

Post Number: 2
Registered: 06-2004
Posted on Tuesday, June 22, 2004 - 12:58 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

My camera is a fairly inexpensive 3.2 Mega pixel Sony and it works great, as you can see. It is a little tricky to get everything lined up but you get used to it pretty quick. Here is another shot:

 

Vance Barnes
Advanced Member
Username: Vancebarnes

Post Number: 742
Registered: 03-2003
Posted on Tuesday, June 22, 2004 - 01:18 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Geoff, for your first post that's a damn good one. Welcome to the B&V.
 

Geoff Buschur
New Member
Username: Avmech

Post Number: 3
Registered: 06-2004
Posted on Tuesday, June 22, 2004 - 02:18 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Thank you both. I have been brewing for 6 years and am a self-taught all-grainer (with a little help from Charlie and John). Believe it or not I just discovered B&V. It has been a long lonely trip until now.
 

Pacman
Member
Username: Pacman

Post Number: 178
Registered: 04-2003
Posted on Wednesday, June 23, 2004 - 12:59 am:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

Crap!!!! my digital camera isn't good enough... Now I have another excuse to buy a better digicam... :-)
Damn Brewing's Fun!!!!
 

David S.
Junior Member
Username: Dsundberg

Post Number: 61
Registered: 04-2004
Posted on Thursday, June 24, 2004 - 02:49 pm:   Edit Post Delete Post View Post/Check IP    Ban Poster IP (Moderator/Admin only)

I've compared my refractometer (Chinese version) to my hydrometer and they are so close I can't tell any difference. I love the fact that I can take an instant reading during the mash/boil and not have to measure temperature and correct with ProMash.

I don't use it once the fermentation has started. That's what the hydrometer is for and you don't have to worry about temperature compensation at this point. Also, as noted above, you get to taste your work!