Calibrating Refractometers and Hydrometers

[Brody]

I've been feeling less than confident in some recent gravity readings.

A relatively cheap refractometer (https://www.amazon.com/gp/product/B00CO ... UTF8&psc=1) I bought almost 2 years ago has been my main tool. Yesterday I calibrated it to 0 with distilled water but was hoping to check it on the other side. I heard a sugar water solution would be no good for some reason? The 28g sugar to 176g distilled water read way higher - when I went to calibrate to 1.048/12 based on that solution my distilled water reading was obviously way to low.

My hydrometer seems to be a mess. It reads <1.000 SG with distilled water but when I tried the solution of 28g table sugar to 176 Distilled Water (supposed to be 1.048/12 based on http://www.eckraus.com/blog/calibrate-h ... hydrometer) I read well above 1.048 (in the mid 1.050s). Not sure if that means I should junk it or plot a chart.

Any inputs on good reliable tools for measuring gravity and calibration tips?

[Brody]

https://www.amazon.com/Milwaukee-Refrac ... ractometer

This was one thought.

[lupulus]

12g of sugar mixed with 92.84g of distilled water will weigh 104.84g and yield a 12% sugar solution at 20C.
Incidentally, you should have 100mL of solution at 20C. This is what in chem/biochem is called a 12% w/v sugar solution.
For 176g of distilled water, you would need 22.749g of sugar to get a 12% sugar solution
It read higher because it was higher

[Brody]

[Brody]

Well I measured that out - my refractometer said 1.044 and my Hydrometer said 1.038.

That makes the Hydrometer low on both Distilled and Sugar Solution tho by different amounts. Wonder if I can trust my refractometer so long as it's reading 0/1.000 with distilled?

[Brody]

Just busted out a bottle tea. 547ml bottle with 42grams of sugar. So ~7.7% extract. Put a drop on the Distilled calibrated refractometer and it read at 1.031/7.7%. So I guess I'm good to rely on this (of course using the post-fermentation calcs) and forget the hydrometer.

[lupulus]

Glad you figured it out

[Owenbräu]

My handheld refrac wouldn't hold a zero. Poor design allowed the scale to shift with temperature changes. I eventually gave up and bought a digital...

[Brody]

Yea, mine seems to need to be recalibrated frequently. Any recs for a good digital?

[Bryan R]

I have used this one for ages.



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