Author Topic: Glass Hydrometer in Plastic Carboy  (Read 807 times)

Offline rgibson89

  • 1st Kit
  • *
  • Posts: 2
    • View Profile
Glass Hydrometer in Plastic Carboy
« on: December 13, 2016, 12:48:35 PM »
I'm new to homebrewing so I apologize if this is a silly question. I also searched the forum a bit and couldn't find the answer. Can I leave my glass hydrometer in my plastic carboy instead of taking multiple samples? Will it be a live reading or is this a wasted idea? Any help is appreciated!

Offline pete b

  • Official Poobah of No Life.
  • *
  • Posts: 3123
  • Barre, Ma
    • View Profile
Re: Glass Hydrometer in Plastic Carboy
« Reply #1 on: December 13, 2016, 01:06:57 PM »
Obviously you would want to sanitize it first. Also you wouldn't want to put it in until after the Krausen drops or it may get too crusty to read. Also it may decide to float over to the side and lean against the side of the carboy so you don't get an accurate reading. Other than that it might be worth trying.Caerefully.
Don't let the bastards cheer you up.

Offline kramerog

  • Senior Brewmaster
  • ******
  • Posts: 1809
    • View Profile
    • My LinkedIn page
Re: Glass Hydrometer in Plastic Carboy
« Reply #2 on: December 13, 2016, 02:52:32 PM »
The other issue is that bubbles can attach to the hydrometer causing the hydrometer to read high.  It is easy to see those bubbles and knock them off when measuring a sample; not se easy inside a carboy. 

The best way to avoid multiple samples is to not take them, which is probably contrary to the instructions you may have been given. 


Offline pete b

  • Official Poobah of No Life.
  • *
  • Posts: 3123
  • Barre, Ma
    • View Profile
Re: Glass Hydrometer in Plastic Carboy
« Reply #3 on: December 13, 2016, 03:31:37 PM »
The other issue is that bubbles can attach to the hydrometer causing the hydrometer to read high.  It is easy to see those bubbles and knock them off when measuring a sample; not se easy inside a carboy. 

The best way to avoid multiple samples is to not take them, which is probably contrary to the instructions you may have been given.
Good point about not taking a lot of samples. I take one sample well after I suspect final gravity is reached and that sample serves both to confirm where my fg has ended up and my first taste of the beer.
That being said, a new brewer doesn't have the same confidence that fg has been reached. Once you have brewed for awhile you know what a beer that has reached final gravity looks, tastes, and smells like. Before that it is a good idea to take a sample 7-10 days into fermentation for a normal gravity beer (maybe >1.070) and then take another 2-3 days later to confirm its not still fermenting.
Don't let the bastards cheer you up.

Offline brewinhard

  • Official Poobah of No Life.
  • *
  • Posts: 3217
    • View Profile
Re: Glass Hydrometer in Plastic Carboy
« Reply #4 on: December 14, 2016, 12:31:25 AM »
I personally would not put anything into my fermenter like that. Rather you would be better off taking a sample from the fermenter to place your hydrometer in. Less risky this way. Just my 2 cents though...

Offline tommymorris

  • Senior Brewmaster
  • ******
  • Posts: 1958
  • Tommy M.
    • View Profile
Glass Hydrometer in Plastic Carboy
« Reply #5 on: December 14, 2016, 12:42:41 AM »
If you wait until the beer is done fermenting to take a gravity sample you get to drink the sample. No beer gets wasted. 

I give it a few days past the krausen dropping to let the yeast floc.   I enjoy drinking gravity samples.

Big Monk

  • Guest
Re: Glass Hydrometer in Plastic Carboy
« Reply #6 on: December 14, 2016, 01:06:48 AM »
Here is a perfect situation for a refractometer. That way you can monitor throughout the entire fermentation stage and pull as many samples as you want without losing volume.

In my old spreadsheet I had dropdowns that account for hydrometer sample loss. I essentially measured the volume of my test jar and used the sheet to increase strike water to account for the 3-5 samples I might take across the fermentation.


Sent from my iPhone using Tapatalk

Offline rgibson89

  • 1st Kit
  • *
  • Posts: 2
    • View Profile
Re: Glass Hydrometer in Plastic Carboy
« Reply #7 on: December 15, 2016, 12:25:29 PM »
Thanks for the input everyone! To out everyone's idea together I could use a refractometer for the intermediate samples and towards the end of the fermentation put the hydrometer in to wait for the final gravity, all while being sanitary, of course.

Offline majorvices

  • Global Moderator
  • I must live here
  • *****
  • Posts: 9607
  • Polka. If its too loud you're too young.
    • View Profile
    • Yellowhammer Brewing Company
Re: Glass Hydrometer in Plastic Carboy
« Reply #8 on: December 15, 2016, 01:09:42 PM »
You aren't going to get a very accurate reading in a bucket simply because you aren't going to be able to see it as well. Use a flask.

Offline Pi

  • Brewer
  • ****
  • Posts: 429
  • "I would never trade tomorrow for today"
    • View Profile
Re: Glass Hydrometer in Plastic Carboy
« Reply #9 on: December 17, 2016, 02:54:43 AM »
Primary:On Reflection APA
Lagering: Vienna
Drinking: Whenever I'm not working or driving