Refractometer before/after fermenting?

I'm using google shopping to look at refractometers. I'm getting a warning that a refractometer is only for an og reading and that a hydrometer is required for an fg. Why? I think it should be able to measure both?

yes you can but you will have to correct for alcohol in the mix that throws off reading a little bit
I use this 2 sites:
http://ee.isa-geek.net/beercalc.htm
http://onebeer.net/refractometer.shtml
and multiple times i confirmed that calculations are correct with hydrometer

You just have do the math. The Benefit for me was the small sample on the cold side. I hated pulling enough beer to fill my test tube just to check gravity in while fermenting. There are some good deals for refractometers on eBay.

Excellent. They have good prices on google, I'll have to check out ebay.
Thanks for responses.

Here's a nice one from a good seller, homebrew stores sell this at almost double the price. The correction works well for final gravity and you may never use a hydrometer again.

http://www.ebay.com/itm/NEW-0-32-AT...300?pt=LH_DefaultDomain_0&hash=item5ad9e6290c

More info:

http://seanterrill.com/2010/06/11/refractometer-estimates-of-final-gravity/

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

I just got the one that DSmith mentioned.I've not used it yet,but it seems to be a decent piece of equipment for the price.

Has anyone used the BREWfractomter listed on Ebay? It's more expensive ($65), but sounds more specifically geared for brewing.

I'd be fine with still having to do calcuations if needed, just wondering if this one maybe takes that step out for you? Just thinking using one of these is so much easier than a hydrometer, and much lest wasteful. Right now I'm just starting with extract kits, and I'd be looking to use it for OG and FG readings.

Having a Brix and gravity scale does eliminate the conversion for wort (OG). I think there is the same $30 one I recommended that has dual units too, just read the eBay descriptions well and look at the picture of the scale. The dual scale doesn't help at all for FG and you will need the OG and Brix reading for FG for the calculators. My experience is that the FG readings can be trusted with the calculators compared to a hydrometer.

I'd save the $35 difference from the more expensive one for another purchase.

I tested my refractometer against my hydrometer last night and I found that none of the sites are completely accurate. I think the closest a site got to was +.005. Conversion stated it should be a FG of 1.013, but the hydro read a clear 1.008.

I'm still on the lookout for a reliable conversion.

Can you post your original gravity and refractometer reading for final gravity?

Bricks41 said:

I tested my refractometer against my hydrometer last night and I found that none of the sites are completely accurate. I think the closest a site got to was +.005. Conversion stated it should be a FG of 1.013, but the hydro read a clear 1.008.

I'm still on the lookout for a reliable conversion.

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In my experience, there is NO completely accurate conversion. What does work is that when the refractometer reading is the same over several days, you know it's done fermenting, and often it's "close enough" even if not totally accurate.

I still usually check FG with a hydrometer and skip the refractometer after fermentation begins.

Yooper said:

In my experience, there is NO completely accurate conversion. What does work is that when the refractometer reading is the same over several days, you know it's done fermenting, and often it's "close enough" even if not totally accurate.

I still usually check FG with a hydrometer and skip the refractometer after fermentation begins.

Click to expand...

+1 to this. I use the refractometer exclusively during brewday and that's it. I might use a hydrometer to check FG, but in all honesty I rarely check FG. Not best practices I know, but if you're confident in your fermentation, who cares?

I depend on my hydrometer for the final gravity, but my go to for the OG is the refractometer. It would be nice to get the reliable conversion for a refractometer FG, but I understand the dozens of variables involved.

can i use these conversion websites for wine also?