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Gravity Increase?

Discussion in 'Kits & Extracts' started by Chap, 26/1/17.

 

  1. Chap

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    Posted 26/1/17
    Hi all, not sure what is happening but my gravity readings seem to be a bit off. OG was 1042 on 19/1, then 1012 on 23/1. Then somehow gravity has increased to 1018 on 25/1 and today. The other issue is I give the hydrometer a spin and it then rises to 1022ish.

    I have noticed there are small bubbles in the tube I put the sample into, almost like there is some carbonation in the beer already. Is this possible and could it be the cause of my off readings? Or is there something else it could be?

    *Other background that may be helpful - Irish Red Ale FWK, aerated well, MJ15 empire ale yeast pitched at 22oC, fermented at 18oC, temp rise to 20oC on 23/1.

    Cheers
    Chap.
     
  2. Danscraftbeer

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    Posted 26/1/17
    Have you taken another sample? Its not carbonation. I test my beers that finish naturally carbonated and it reads correct. Just a bit of spinning the hydrometer will disperse any carbonation anyhow. Gently tap down the hydrometer to hit the bottom of the tube to shake off any bubbles that may be clinging to the hydrometer. Give the tube a gentle flick/tap should release the bubbles etc. Little things you learn to get accurate readings. Make sure the tap is clean and has no dried wort residue (assuming you use a plastic fermenter etc)
    A bit of malt goo in the sample would give such a false reading.
     
    McDuck likes this.
  3. Chap

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    Posted 26/1/17
    And just like that it's all good. Tap was clean and no residue (yes plastic fermenter). Pushed hydrometer down and tapped on the bottom. Lots of tiny air bubbles made their way up to the top. Reading 1012. I normally just spin the hydrometer and its normally pretty accurate. Thanks for the tip, like you said, it's the little things you learn.

    Cheers
    Chap
     
  4. swiftyb

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    Posted 27/1/17
    What about temperature difference? As in was one reading taken when it was significantly warmer than the other?
     
  5. Droopy Brew

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    Posted 27/1/17
    Yeah mate thats exactly what it is. As yeast ferment they produce alcohol and CO2 (amongst a myriad of other compounds). The CO2 does carbonate your beer and is most noticable during high ferment activity. As fermentation slows and stops the CO2 releases from solution.
    So yes the CO2 bubbles will cling to your hydro and give you a higher reading. So removing them by spinnning or knocking the hydro is required for an accurate reading.
     
  6. Lionman

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    Posted 1/2/17
    Some of my brews are carbonated enough that a pour from the fermenter tap will form head in the hydrometer tube.

    This will definitely affect the reading, apart from not being able to see the surface of the liquid through the head, the bubbles that form on the hydrometer make it more buoyant which will increase the SG reading.

    I usually leave it sitting on the bench for an hour or two to flatten out and then take the reading.
     
  7. McDuck

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    Posted 23/7/19
    My god thank you for this input, I was at 1016 yesterday and today I thought I was at 1025.
    Legend mate,
     

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