Refractometer and hydrometer not agreeing

[Whisky River]

One thing that was hard for me was to accept "close enough". I'm a weirdly geeky perfectionist, and 20 years ago the difference between 1.048 and 1.052 would have bothered me. But really, a difference of .004 is 'close enough' as our equipment is not lab quality or that precise.

I do use a Tilt (like the Rapt pill, but I hate the Rapt stuff so don't use it, including the temperature probe), but it's not even that I need accuracy/precision now- just so I know the beer is done. It doesnt' really matter to me if it's finished at 1.012 or 1.016- it's 'close enough'. If it's finished, it's not going to get more finished so I'm good with it.

That said, I do know my wort correction factor, and my refractometer and hydrometer generally match at the end of the brew day. My Tilt is calibrated then too. And I really that what the refractometer reads and what the hydrometer reads are different but still useful data points. The data points just let me know if the beer is finished, and the approximate IBU:OG ratio. And really, the beer is great.

(I too hate the rapt environment)

One thing I came to learn about myself is that I’m ok with “close enough” because I can always improve if I know where I’m at, but I can’t stand not knowing if my measurements are reliable. I’m fine with getting 1050 on a 1052 target (not really, but I can stand stand it) but it’s incredibly frustrating to get one form of measurement that says I got 1048 and one that says 1052. I tried every device I could and at the end I realized that consistency and technique in using the tool is at least as important as how “accurate” the tool is. If my procedure for pulling a sample isn’t consistent I can still get 2 different readings from the Easydens and that’s about as reliable a measurement device as I can imagine short of true lab grade equipment. I buy almost all my gear used and got a deal on several tilts and now I use 2 tilts in the fermenter because Ive got them lying around and having just one and not being able to trust the measurements because it might be hung up on something drives me nuts!
So beware of thinking there’s something out there that will give you real certainty, it’s elusive and the path to find it has lots of tempting but probably unnecessary gear on it.

 

[kohalajohn]

I own two Pills but I have to agree with @dmtaylor they do have accuracy issues reading SG when yeast and hop debris are stuck to it. However, for me the Pill is invaluable in displaying the overall rate of fermentation, and also letting me know when FG is reached. But I still always check OG and FG with a hydrometer to make sure my Pill is in the same zip code.

Yes, it makes sense that in full krausen, yeast and foam and hop debris could pile onto the Pill and affect accuracy.

But wouldn't this mainly be a problem only in mid fermentation, meaning full krausen, and not near the start or finish? Since it's the start and finish I care about, a mid ferment error would not be very important to me.

Also I read that the new Pill software will scan through the hundreds of readings and throw out what are obvious outliers.

Still considering a Pill for me. I get that it's not for everyone.

 

[Yooper]

Yes, it makes sense that in full krausen, yeast and foam and hop debris could pile onto the Pill and affect accuracy.

But wouldn't this mainly be a problem only in mid fermentation, meaning full krausen, and not near the start or finish? Since it's the start and finish I care about, a mid ferment error would not be very important to me.

Also I read that the new Pill software will scan through the hundreds of readings and throw out what are obvious outliers.

Still considering a Pill for me. I get that it's not for everyone.

Well, yes, but.....the krausen sticks to the device and weighs it down. That affects accuracy quite a bit. If the hops debris and krausen just disappeared when the krausen falls, it wouldn't matter.

I have a Tilt, and I love it and once it a while some hops from dryhopping drop it down and it gets inaccurate, but usually it's just fine and close enough!

 

[Broothru]

Yes, it makes sense that in full krausen, yeast and foam and hop debris could pile onto the Pill and affect accuracy.

But wouldn't this mainly be a problem only in mid fermentation, meaning full krausen, and not near the start or finish? Since it's the start and finish I care about, a mid ferment error would not be very important to me.

Also I read that the new Pill software will scan through the hundreds of readings and throw out what are obvious outliers.

Still considering a Pill for me. I get that it's not for everyone.

The accuracy of EasyDens data can definitely be inaccurate if the sample is cloudy or or not degassed, just as readings can be inaccurate in refractometers (if optically cloudy, interfering with spectral refraction) or CO2 bubbles adhering to the bulb of a hydrometer.

If my O.G. sample pre-pitch or high krausen is cloudy, I strain it through a paper coffee filter. If there is a lot of gas present, I vigorously stir the sample briefly to disperse the CO2, just like I did when using a refractometer or a hydrometer.

When I first got the EasyDens, I took parallel readings with hydrometers, refractometers and the Anton-Parr, both clear and unsettled. Multiple readings of the same sample on the same device often showed different values (generally small, not consistent) on the refractometers and hydrometers, but not the Anton-Parr.

The variance between unsettled/gassed values is smaller (or zero) with EasyDens. Carefully cleared and degassed samples measured on all devices are generally the same, although muddled samples diverge less from clear samples with EasyDens.

So, in general the EasyDens appears to be more accurate in measuring cloudy samples than the other devices. Plus, its ease of use, consistency, small sample size requirement, speed of use, automatic temperature compensation result in a very useful tool.

 

[kohalajohn]

Well, yes, but.....the krausen sticks to the device and weighs it down. That affects accuracy quite a bit. If the hops debris and krausen just disappeared when the krausen falls, it wouldn't matter.

I have a Tilt, and I love it and once it a while some hops from dryhopping drop it down and it gets inaccurate, but usually it's just fine and close enough!

Sigh. Nothing is perfect.

I can see why people just stick with a hydrometer. It does work and is simple.

There was a post earlier about an easier to read hydrometer. That certainly is worry free.

https://fhsteinbart.com/product/specific-gravity-range-precision-hydrometer-1000-1070-sg/