Refractometer Use

Beermates,
I recently purchased a new refractometer from NB, as my old hydrometer broke (and I wanted an easier way to measure SG). I’ve found that often times when I’m measuring OG, there is lots of “stuff” suspended in the wort. I assume that these are sugars and occur because of the cold water I add to top off the 5 gallons. My concern is that I always seem to get low OG readings with the refractometer. Could it have something to do with the suspended solids? Am I doing something wrong?
Chet

I think the stuff suspended in the wort is small tidbits of grain and has no effect on the SG. I merely give mine a stir and try to let the sample cool for a few seconds before taking the reading.

Have you calibrated it yet ?

It sounds like you’re doing partial boils and topping off. It will be hard to get your wort mixed enough to get a reliable sample if that’s the case. You can take a reading predilution and calculate the final gravity. BeerSmith has a calculator for this and this article in BYO describes the math

http://byo.com/stories/item/237-blendin ... techniques

The only online calculator I’ve uses liters

http://www.jimsbeerkit.co.uk/calc.html

I have not calibrated the refractometer. I purchased the ATF version, so the only calibration I did was put regular water on it and make sure it said 1.000 (which it did).

Here’s the link to my model:

http://www.northernbrewer.com/shop/brix ... w-atc.html

Update. So, I purchased a new hydrometer to compare with the refract. Brewing the winter warmer and its been in primary for 3 weeks. During the transfer to secondary, I took a reading with both the hydrometer and the refract. Results - hydrometer 1.016 (what I would expect at this point), refract 1.037 (way too high). So, is my refract defective? What else could cause the discrepancy? I about ready to return it to NB.
Chet

[quote=“chetgregg”]I have not calibrated the refractometer. I purchased the ATF version, so the only calibration I did was put regular water on it and make sure it said 1.000 (which it did).

Here’s the link to my model:

http://www.northernbrewer.com/shop/brix ... w-atc.html

Update. So, I purchased a new hydrometer to compare with the refract. Brewing the winter warmer and its been in primary for 3 weeks. During the transfer to secondary, I took a reading with both the hydrometer and the refract. Results - hydrometer 1.016 (what I would expect at this point), refract 1.037 (way too high). So, is my refract defective? What else could cause the discrepancy? I about ready to return it to NB.
Chet[/quote]

No, you need to go here http://www.northernbrewer.com/refractometer-calculator/ and plug in your numbers. Once you have alcohol in solution it will read wrong so you have to use the calculator to figure your correct gravity.

thanks for the calc link.

“I think the stuff suspended in the wort is small tidbits of grain and has no effect on the SG. I merely give mine a stir and try to let the sample cool for a few seconds before taking the reading.”

so when you’re taking your post-fermentation reading, do you have to worry about hops affecting things? how about carbonation? can you take a reading out of the tap or do you have to rely on the reading from your 2ndary?

You can/should also look at Sean’s refractometer calculator:

http://seanterrill.com/2012/01/06/refra ... alculator/