Refractometer question x2

[yesjenks]

Hello All,

Getting ready to buy a Refractometer. What devise do you us to remove test samples from your carboy? Obviously, it must be long and skinny.

Thank you,

Jay

 

[ong]

A wine thief is the easiest way. You can get them in glass, plastic, or stainless.

Do note that a refractometer will not provide accurate measurements once fermentation has begun.

 

[PGEduardo]

A wine thief is the easiest way. You can get them in glass, plastic, or stainless.

Do note that a refractometer will not provide accurate measurements once fermentation has begun.

Wine thief = Hydrometer

Pipettes = Refractometer

I've heard you can use a refractometer after fermentation has begun with proper conversion formulas (I've never tried it).

http://www.amazon.com/dp/B005CD2I50/?tag=skimlinks_replacement-20

edit - just realized he mentioned carboy, not kettle. You only need a couple of drops so in that case a long sterilized piece of plastic or metal should still work (assuming refractometer results are accurate after active fermentation has subsided...)

 

[yesjenks]

Thanks for your replies!

Why won't a refractometer be accurate after fermentation? What's the best devise to read specific gravity during/after fermentation?

 

[Bowtiebrewery]

Because alcohol will throw off the reading... There are calculators online that can calculate based on potential alcohol in solution, but I've found that its not 100% accurate. I always use my hydrometer for readings out of the carboy... during fermentation that is.

 

[jwalker1140]

Depending on the fermenter, I'll draw out a sample with either a 1ml or 10ml pipette, or maybe a wine thief if I want extra to taste. I suppose a racking cane with the little black cap on the end would grab enough for testing, too. Many ways to skin that cat....

I've been using a refractometer to monitor fermentation for about 4 years or so, with both brewing and winemaking. At first (being a skeptic by nature), I compared my readings against my hydrometer every time. I stopped doing this after ~20 such comparisons because they were either exactly the same, or the difference was so slight that it simply wasn't meaningful to me. YMMV.

Something to consider if you decide to similarly compare results, at least if your hydrometer is one of those common $6 triple scale hydrometers: if you do observe a difference in readings, how will you know which device (if either) is giving you the correct reading? Surly we don't trust those triple scales that much, right?

 

[phug]

You could use a sanitized straw with a finger over one end to grab you sample.

I noticed a big difference between my hydrometer and my refractometer, so I compared them using calibrated sugar/ water solutions and found they were both off, but that my hydrometer was off by more. 6% high vs 3% low

 

[yesjenks]

Thanks for all your feedback.

I assumed a refractometer always measures the density whatever liquid being tested. I didn't think alcohol would be a factor.

Do you know if alcohol is less dense than water?

What's the best way to measure gravity? The $6 hydrometer at my HBS?

 

[phug]

Alcohol is less dense than water. And the six dollar hydrometer from your lhbs is a perfectly good tool for measuring gravity.

 

[WissahickonBrew]

You can go purchase a wine thief but don't forget you only need a little more than a drop of liquid. Why not find something long and metallic (clothes hanger?) around the house that you can easily sanitize, dip into your carboy and place a drip on your refractometer?

 

[frazier]

What's the best devise to read specific gravity during/after fermentation?

The best way to check gravity during fermentation is - DON'T DO IT!!

Really, there is no reason to check while fermentation is happening. There is nothing to learn, unless you want to chart the gravity day-by-day as part of a science project or something.

I check the gravity twice - once on brewday, and once on bottling day.

Cheers!

 

[Andyoesq]

https://www.homebrewtalk.com/f39/not-panic-just-trying-understand-519133/index2.html

I had similar questions about using the refractometer, got some good advice (above) and have been able to take pretty accurate post fermentation refractometer readings