Testing the tester, hydrometer check

Been a bit quite around here. Sorry about that. Chas is taking it easy on the brewing front and I was away interstate for a nine day holiday. Back now.

As I mentioned in the write up of the bottling day of the Summer Ale, I cracked another hydrometer. That’s three dead in two years. Lucky for me I have a spare, but it’s still a pain. My preference is to have one really good hydrometer that I can use, and keep.

Over the last few days I was thinking about this, and feeling sorry for myself. I was also concerned that all the gravity readings for the Summer Ale might be wrong. What could I do? Then I realised I could check it against the good hydrometer. Get a reading with the broken one, and check what it is with the working one. I still have an older one with with a missing tip (where glass broke off) and thought it would be good to see what its readings were.

So, using water and a whole lot of table sugar that’s exactly what I did. I filled up a tube, added some sugar, stirred and shook it up, then took a reading with all three hydrometers. Then added more sugar tested with all three again, and repeated.

Gravity readings as follows:

Testing equipment

Testing equipment with tubes and hydrometers

  1. Not Broken = 1.000
    Cracked = 0.997
    Missing Tip = n/a (not enough to float in)
  2. NB = 1.005
    Cr = 1.001
    MT = 1.008
  3. NB = 1.025
    Cr = 1.021
    MT = 1.029
  4. NB = 1.048
    Cr = 1.043
    MT = 1.052
  5. NB = 1.060
    Cr = 1.055
    MT = 1.064

Overall it looks like the cracked one is 0.003 to 0.005 below what it should be. The one missing its tip is 0.003 to 0.004 above what it should be. Both of those are pretty close. The variations in the difference could be put down to me not reading the gravity correctly and/or sugar still dissolving into water. In theory I could continue to use these broken hydrometers and adjust by +0.005 or -0.004 each reading. That’s not ideal, so I’ll still buy a new one.

What does this mean for the Summer Ale? Not much. As original and final gravity reading would have been out by (about) the same degree, it’s still 3.3% alcohol. And it will be time to try it very soon.

– Mikey

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1 thoughts on “Testing the tester, hydrometer check

  1. Bishop says:

    Loved the hydrometer blog….my misadventure involved one where the bottom tip broke off and a lot of the weighting material was missing. It floated so high I thought I had and incredibly dense wort! No spare. Now I have two.

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