Reading My Hydrometer

[Redwulf]

Bit of a Daft Question, my Hydrometer has a bold line under each .010 and 5 gradients. I've been reading the bold line as the "ten"

Is this correct.

When I do a reading of tap water it sits at the bold line under 1.000

 

[strange-steve]

This is the 1.000 mark (pink arrow) and the 1.010 mark (blue arrow), the small notches are 0.002 increments:

 

[Redwulf]

This is the 1.000 mark (pink arrow) and the 1.010 mark (blue arrow), the small notches are 0.002 increments:

Perfect, Thank you Steve.

 

[zeptobrewer]

Also worth noting that the bottle and ferment ranges are very much guidelines! It's much more important that the final gravity is constant before bottling (and is about what you'd expect) than it just being somewhere in the yellow zone.

 

[Edison]

And don’t forget to measure the temperature of the sample. If your hydrometer is calibrated to 20c (highly likely) if your sample is more than a couple of degrees either side of this, either adjust the temperature of the sample or use an online calculator otherwise your reading could be way out. This catches a lot of new people out!

 

[Redwulf]

And don’t forget to measure the temperature of the sample. If your hydrometer is calibrated to 20c (highly likely) if your sample is more than a couple of degrees either side of this, either adjust the temperature of the sample or use an online calculator otherwise your reading could be way out. This catches a lot of new people out!

Yes, I've noticed this and panicked a bit when I took the first reading of my MJ Raspberry Berlinner which was a bit hot, it was about 1.030 when it was warm and went up to 1.038 once it cooled down a bit.

 

[terrym]

Yes, I've noticed this and panicked a bit when I took the first reading of my MJ Raspberry Berlinner which was a bit hot, it was about 1.030 when it was warm and went up to 1.038 once it cooled down a bit.

For a hydrometer calibrated at 20*C, measuring most beers within normal brewing and conditioning temperatures, you should not normally expect to have a correction exceeding 0.002, its usually less. More here
https://www.brewersfriend.com/hydrometer-temp/In your example it is likely your wort was not properly mixed at the time you took your first OG reading and as it cooled down and time passed the undissolved sugars became homogenised into the wort and then gave you an accurate reading.