Is this hydrometer reading right?

[mattdean4130]

Okay, so I commented over at the coopers forum on a yeast reculture thread, and one of the guys suggested the numbers i was getting might not be correct....

So here's a couple of pictures,

Plain old tap water....

This one's a Real Ale with 1Kg BE2 & 100g dex on day 5 @ 21deg, IG was 1033 @ 28deg

And this is an India Pale Ale 1kg LDM, 500g Dex i just put down (20ltr) @ 28deg

What do you guys think?

The bloke over at coopers thought it strange i was reading consistently FG's around 1000 (7 days, all beginning IG's early to mid 1030 - 1035's

It doesn't really matter that much, i mean if it's dropped 30 points over 7 days and stable over 48 hours it should be done and i'm happy the yeast has done its job. ABV isn't really super important to me - but it would be nice to know if my hydrometer is out or not!

Cheersies!

:drinks:

 

[jaypes]

Your hydro should read 1.000 in tap water at 20 degrees

some of your readings are at 28 degrees which my throw a couple of points for your hydro.

I would get another good quality one from your LHBS just to make 100% sure

 

[sp0rk]

Hey matt, looks like your hydrometer might be out by .0080 points
add this on top of your readings to correct
or go see Geoff at Coffs Home Brew in Max Murray Mall and grab a new one if it's too annoying

 

[Dan Pratt]

Buy a refractometer. That hydrometer is not right.

 

[mattdean4130]

I usually use an online temperature calculator when i work out the alcohol content, i write temps down with each reading...

But yeah i thought tap water should be 1.000 - TBH i never really checked it. Only use the hydrometer really to know when i'm at final gravity..

Handy to know, i might have to upgrade it to a better quality one next time i'm in the LHBS (I've been almost living there the last couple of weeks! I've put down two pale ales, i've got a real ale a couple days from bottling and i just put an IPA down tonight (1.044 + .08 :blink: THAT's going to be strong!)... After that, i think a toucan stout and a fruity/spicy style pils and i should be right for a while!)
:beer:

 

[yum beer]

Buying one from the LHBS does not guarantee anything, I have been using the 'dodgy' plastic one from a coopers kit( that was 3 points under) for quite a while after breaking several glass ones,
I scored a proper hydro off a mate who had a few. Great I thought. When I tested it was exactly the same as my plastic one, 3 points under.....
Doesnt matter if its spot on or not, its a tool to check progress, stable readings are stable readings, gravity drop is still the same points for ABV calculations.....
Spend your twenty bucks on something else.

 

[iralosavic]

Considering you basically lose 1 point for every 5c, ie 20c = 0, 15c = -1, 10c =-2 etc I would say your hydrometer requires replacing.

 

[bum]

Doesnt matter if its spot on or not, its a tool to check progress, stable readings are stable readings, gravity drop is still the same points for ABV calculations.....
Spend your twenty bucks on something else.

Just to expand on this good point (in case OP doesn't know), all you have to do is work out how much it is out by then adjust all readings by the same amount. A hydrometer that reads wrong is not broken, it just needs calibrating.

Sometimes the paper inside can be shaken to read a bit closer to true as well.

 

[iralosavic]

Just to expand on this good point (in case OP doesn't know), all you have to do is work out how much it is out by then adjust all readings by the same amount. A hydrometer that reads wrong is not broken, it just needs calibrating.

Sometimes the paper inside can be shaken to read a bit closer to true as well.

That is a good point. I have a few hydrometers, myself... keeping track of calibrations is easy (ie write notes in a book or whatever), but it's just one less thing to worry about if you have one that is calibrated to zero. And the OP's is really inaccurate... I wonder how it got so bad or if it was a manufacturing error. Considering how cheap they are, I just replace mine. Each to their own I guess.

 

[bum]

Definitely a fair point. Not having to think about it ever again might be worth the $15 (or whatever) a hydrometer costs for many brewers. I just thought it was worth pointing out that it can still be used as is, if OP were so inclined.

[EDIT: sweet, beautiful drunk-talk]

 

[KingKong]

Would the fact its resting on the side of the container affect much? I always make sure to give it a twist and keep it off the side where I find the bubbles that stick between the hydro and wall of the container can stuff the reading.

 

[iralosavic]

The angle makes it harder to read and less accurate, but not by the degree pictured. Spinning the hydro is fun; I often do it 5 or more times even after I feel I've got a good read; just to be sure, of course.

 

[wbosher]

If it's a plastic Coopers one, you can snip a little of the plastic from the top, a few mm at a time. That will lift it up a little until it reads zero.

 

[mattdean4130]

If it's a plastic Coopers one, you can snip a little of the plastic from the top, a few mm at a time. That will lift it up a little until it reads zero.

Awesome! I'll give that a go today, cheers!

 

[wbosher]

Just make sure it's 20C water.

 

[cremmerson]

My brewing notes have three gravity readings at each point:

1. Hydro reading
2. Corrected reading (I know it's four points under at 20C, so add this on) and
3. Temp adjusted reading (http://www.brewersfriend.com/hydrometer-temp/)

So I get there in the end and don't mind the adjustments. But the point above regarding stability is the key - the rest just lets me know how much abv a brew is packing.

 

[wbosher]

Managed to find the link to an old post of mine regarding the Coopers hydrometer and calibrating it. I see it mentioned quite a lot around here that the Coopers hydro is faulty, but chances are it just needs calibrating.