SG increasing during Fermentation?


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Oct 19, 2018
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I've got a Tilt Hydrometer in a batch of beer right now. Seemed like the SG was stalling so I stirred it up this morning. Prior to stirring, I got an SG of 1.044 at 69 degrees Fahrenheit. After stirring it up, I checked the Tilt hydrometer and it showed 1.050 at 69 degrees Fahrenheit.

I'm thinking that there may be a couple reasons for this.
  1. The wort around the Tilt was actually at 1.044 and when I stirred it up, the SG equalized with the other wort that was higher than the wort that was around the Tilt.
  2. An air pocket, yeast, trub, or something else could have become attached to the Tilt hydrometer causing an incorrect SG reading.
Thoughts on why this happened?
Thoughts on how to fix it?
Stirring won't cause higher or lower readings in different areas of the wort. Tilt sensors seem notorious for being affected by CO2 bubbles. By stirring, you'd have released a lot of CO2 from suspension and it messing with the reading.
So you think that by stirring it the SG went up due to the increase of CO2 release? I guess that makes sense. Then by that rationale, I should be able to wait a few hours and it will settle back down to the correct SG?
Use the tilt more as a relative measurement and don't assume it is accurate in a real fermentation.

For example, my calibrated hydrometer measured some wine as 1.072. My calibrated tilt said it was 1.084.
I've had my tilt report SG going from 1.022 to 1.040 during fermentation.

Yeast sludge, hops trub, krausen leftovers, CO2 bubbles... anything that can cause the tile to, er, tilt more or less from its free-floating condition will cause an erroneous reading. This doesn't mean the tilt is a bad tool (I love mine!), we're just at the limits of its performance.
It may, and it may not.
What is changing is the signal that the device is sending.
I guess these devices are helpful for monitoring progress and temperature.
When to add hop additions, when to change temperature for whatever reason.
I think that a lot of commercial craft brewers use them when they have multiple batches on the go.
It's perfect to show when fermentation is finished. Flat line for a day...
Krausen on the Tilt is more likely. I use Tilts and they do have the tendency to collect it but once it hardens on the top, as Krausen dies down, the Tilt still works but may be a couple of points out but the rate of change will be accurate. You will still see the FV level off.