Refractometer

[Shaneoco1981]

Hey guys, I just got a refractometer in the mail with in the last couple of days. It's the kind that gives brix and specific gravity. I was bottling today and I decided to give it a try. It gave me a specific gravity of 1.026, which I thought was odd. I then used my hydrometer to get a "second opinion" and it gave me a specific gravity of 1.011. Does any one have any idea why it would be so off? P.s. I did use it on water and it gave me a specific gravity of 1.000.

 

[JeepDiver]

Refractometers are for pre-fermentation. There are some conversion formulas/tools you can use for once Fermentation has started. (Personally at that point I just use my hydrometer)

 

[BendBrewer]

It's only accurate without calculations on unfermented liquid. You can use calculators and the OG to calculate the gravity on fermented beer and get close. Or use a hydrometer outside of brew day.

Sorry.

****edited as there is no such thing as unfermented beer.

 

[Shaneoco1981]

Do you guys know where I might be able to get the calculations for future reference?

 

[the_bird]

There are adjustment tools built into BeerSmith, which is a really useful piece of software to have anyway.

 

[sjjn]

Do you guys know where I might be able to get the calculations for future reference?

He was just on Basic Brewing Radio talking about how he's improving on the current formulas.

http://seanterrill.com/2011/04/07/refractometer-fg-results/

 

[BendBrewer]

Brewzor app for Smart phones has one. Under Brewing Calculators.

 

[davel57]

Google: [refractometer beer calculator] and you will find several. Not sure what formula any of them use.

 

[bottlebomber]

Wait a minute, why aren't refractometers useful for checking FG? I just bought one and will be using it tomorrow :/

 

[DeafSmith]

Wait a minute, why aren't refractometers useful for checking FG? I just bought one and will be using it tomorrow :/

Because with alcohol in the solution, it's no longer a simple sugar and water solution - the alcohol changes the way the light is refracted.

 

[erikpete18]

The alcohol in the beer throws off the reading so the light deflection isn't correct. So long as you know the OG, you can calculate pretty well what the FG would be. I know Austin Homebrew has an online calculator on their product page. However, I'd agree that its just easier to use a hydrometer for the FG, I've found its terribly difficult to try to drink the sample off the refractometer .

 

[bottlebomber]

Because with alcohol in the solution, it's no longer a simple sugar and water solution - the alcohol changes the way the light is refracted.

Dammit why do I always find this stuff out AFTER I buy something... is there any way to compensate? Why the heck do they sell these things if it isn't useful through the whole process... *pissed*

 

[ayoungrad]

Dammit why do I always find this stuff out AFTER I buy something... is there any way to compensate? Why the heck do they sell these things if it isn't useful through the whole process... *pissed*

I got one knowing this. They are much better than hydrometers for checking gravities post mash/sparge and post boil. Quick, accurate at any temp and only a few drops are needed.

 

[dantheman13]

You can use refractometers to measure FG as well, as long as your beer is mostly attenuated. I just listened to two very informative podcasts on Basicbrewing.com. The first explains how to use a refractometer (and hyrdometer), and the second podcast is a followup with the same guest who has developed a new, supposedly more accurate formula for determining the FG (as accurate as a hydrometer):

Refractometers and Hydrometers

New Refractometer Formula

Here are the details of his results, and an easy to use spreadsheet tool for using his formula.

 

[ajf]

Do you guys know where I might be able to get the calculations for future reference?

http://byo.com/stories/projects-and-equipment/article/indices/29-equipment/1343-refractometers
It works about as well as Beersmith or Promash (which is not very well in IMO).

-a.

 

[VTBrewer]

http://www.clubhomebrew.com/refracto.xls

I maintain one for each of my brews and find it quite useful. If I'm intending to sample i'll pull one of and use a hydro, but refracto during mashout and brew day, and when checking after that.

 

[fckwalm]

brewhaha2057 ... i did this too... just ordered one and didnt realize... but didnt spend too much on it so not too upset (27 after shipping)

 

[SpaceJunk]

Because with alcohol in the solution, it's no longer a simple sugar and water solution - the alcohol changes the way the light is refracted.

Interesting. I also recently bought this refractometer. I would assume however that you could still use it to check if fermentation is complete, as the reading would stay consistent?

 

[emjay]

Interesting. I also recently bought this refractometer. I would assume however that you could still use it to check if fermentation is complete, as the reading would stay consistent?

Yes. I don't even bother using a hydrometer until bottling time.