3

The reason I ask is threefold.

  1. I watched my gravity readings go up from 1.039 to 1.043 as I cooled my wort before I pitched.
  2. I noticed in the System page of my TiltPI, it says SG 15C/59F (default)
  3. When I cold crash, the gravity readings go up. When I enter the temperature and gravity reading in a hydrometer temperature adjustment calculator, the gravity is the same as before the cold crash.

It seems beyond reason that this device would need to be adjusted for temperature, since it is both a hydrometer and thermometer, but that appears to be the case.

3
  • 1
    I searched around on the internet and on their FAQs. I believe TILT doesn't do this automatically (and probably shouldn't). It seems to have two independent sensors providing data. The good news is- this could probably be solved in the TiltPI UI. My advice is file a feature request to Tilt for TiltPi to have an Adjusted gravity option.
    – rob
    Jun 8, 2022 at 14:08
  • Also.. I've never used the TiltPi system (yet!) but if it's like other Pi systems you could probably modify it to do..whatever you want. It usually requires a little technical know-how. If you don't have the skills..you can usually trade a few homebrews to someone who does ;)
    – rob
    Jun 8, 2022 at 14:09
  • 1
    Dang. I had always assumed (since it produces values for both Temp and SG) it would correct. I use Beersmith which imports the Tilt data, but now it seems I need to fiddle with the values after they are imported. Disappointed. However, it does explain some odd values I have gotten now and then. Jun 18, 2023 at 13:49

2 Answers 2

1

I know this ? is a bit old, but I just got some info in this regard directly from the manufacturer. Here's what they say...

  1. Between 55°F and 90°F -- no adjustment is needed. The casing of the Tilt and the air inside it contract/expand at the same rate as the wort. As a result, in that temp range, any adjustment would be negligible.

  2. Outside that range, the Tilt expands/contracts more rapidly than the wort itself. As a result the adjustments would be opposite those of a normal hydrometer (i.e., falsely gives a low reading for cold wort, and falsely gives a high reading for hot wort)...

  3. Below 55°F: adjust by adding 1 SG pt (0.001) for every 10°F below 55°F.

  4. Above 90°F: adjust by subtracting 1 SG pt for every 10°F above 90°F.

Hope this is helpful. Good to know that no adjustment is needed at normal fermentation temps.

2
  • Yeah, this simply doesn't match my empirical data of 50+ batches. In my experience, it behaves like a normal hydrometer, calibrated at 59F. You can largely ignore any calibration if you are using a consistent temperature. However, if you are ramping or crashing, you will get incorrect results without calibrating the reading to the temperature. I think you got a hold of someone blowing smoke :-)
    – Wyrmwood
    Jun 25, 2023 at 13:39
  • It is correct in the direction, but not near enough in the quantity of the adjustment. Just use a standard adjustment for temp and it will be accurate.
    – Wyrmwood
    Jun 25, 2023 at 13:45
-1

Beer, like most liquids becomes less dense at higher temperatures but this effect also depends upon the alcohol content so it would be hard to reliably calibrate out. In reality I would strongly advise that hydrometers based on the tilt principle are great for showing variations in SG but are not particularly reliable as an accurate measure of absolute gravity. Therefore they are best used as a means of keeping track of the progress of a fermentation from day-to-day, but when it comes to establishing the final gravity of your brew it's best to use a hydrometer.

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