National Homebrew Club Ireland

Brewing Discussions => Equipment & Chemicals => Topic started by: Ceedee on June 05, 2018, 11:34:49 AM

Title: Hydrometer reading
Post by: Ceedee on June 05, 2018, 11:34:49 AM
Something I've always been unsure about...see photo

https://imgur.com/a/9Au6DvN (https://imgur.com/a/9Au6DvN)

For the hydrometer reading of 1040 for example, is the '40' mark at the line under the 40 or the mark to the left of it ? I used to read to the left, but then thought whats the purpose of the line under it? If it's the line under the 40, then I've missed my target gravity of 1046 :-(

Title: Re: Hydrometer reading
Post by: Phil.cork on June 05, 2018, 11:41:58 AM
Pretty sure you read it from the point where the liquid is flat across the top (lower meniscus this wikipedia explains better than me: https://en.wikipedia.org/wiki/Meniscus_(liquid) (https://en.wikipedia.org/wiki/Meniscus_(liquid))) that would make this look like 1046 to me although difficult to tell exactly as you should be reading it at eye level.
The 1040 refers to the line below the 40 mark to directly answer your question.

I'm not that experienced a brewer so happy to be corrected on this
Title: Re: Hydrometer reading
Post by: irish_goat on June 05, 2018, 11:43:57 AM
For an ABV reading it doesn't matter as long as you use the same method for OG and FG surely?
Title: Re: Hydrometer reading
Post by: Ceedee on June 05, 2018, 11:51:18 AM
Quote from: irish_goat on June 05, 2018, 11:43:57 AM
For an ABV reading it doesn't matter as long as you use the same method for OG and FG surely?

Yep, I've always read "across" for OG and FG, so no prob for ABV calculations. Was brewing the "Patersbier" from Greg Hughes' book at the weekend and was chuffed that I hit the OG of 1046 bang on, until a "helpful" friend pointed out that it was actually 1044.
Title: Re: Hydrometer reading
Post by: Phil.cork on June 05, 2018, 01:05:36 PM
True so long as the same both ways. Leaving cert chemistry teacher shouting at us how to read them makes me unable to do it any other way. Not psychologically scarred at all though I swear
Title: Re: Hydrometer reading
Post by: SprocketFuel on June 05, 2018, 03:20:23 PM
easy way to work out where the marks should be is use water......1.000 and the bottom of the section then 1.040 is the bottom of the section
Title: Re: Hydrometer reading
Post by: molc on June 05, 2018, 04:14:00 PM
Its the line around 990 that makes it so confusing to read - I was doing the same thing for years myself! Now I read to the long line below the number after doing a water test.