Hydrometer headaches

[Frognostic]

After breaking my previous hydrometer when it rolled onto the floor in the night I had to get a new one.

Problem is that the readings on this new hydrometer were uncharacteristically high than what I was used to (I was following some fairly straight forward mead recipe that gave me a predictable gravity reading).

I looked into it and did a gravity reading for tap water and it was about 1.006 which is more than it should be, I think, by about 6 points.

Naturally I subtract about 6 points when I take a reading. Thing is the readings were coming in about 15-20 points higher than I was used to and this got me wondering.

It seems that this new hydrometer calculates potential alcohol differently to the old one and by that I mean it predicts higher alcohol content than before.

For example, 1.070 translates as just over 11% potential alcohol whereas before it would have been a potential alcohol of 9.5%.

The red "start beer" bar is between 1.030 and 1.040 and the potential alcohol of 1.040 is given as 6.5%.

The make of the hydrometer is Stevenson Reeves Ltd.

 

[Mexibilly]

According to @ajdelange 1lb sucrose in 1 gallon of water results in 1.0462.
Maybe make this solution and see what your hydrometer reads. If it's still 6 points over then you're calibrated

 

[GilaMinumBeer]

Are you correcting for temperature?

Perhaps try distilled and correct for temp to be sure. Could also be that your previous hydro was inaccurate.

Personally, I always ignored PA scales. They have little value in regards to yeast potential and wort composition/fermentabilty.