First timer, gravity reading question.

Discussion in 'General Brewing Discussions' started by Tmcg38, Feb 11, 2016.

  1. Tmcg38

    Tmcg38 New Member

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    Hi everyone.

    Brewed my first ever batch a couple weeks ago. All grain, full boil, a brown ale. Everything seemed to go very well, wort smelled good, nice brown color, very sticky. Never could get a very good gravity reading with a hydrometer, maybe because it was my first time. Seemed like it fermented very well, bubbling after about 14 hours from airlock, got a real good krausen(?), cleared up nice. Took a gravity reading today, hoping to bottle this weekend and my hydrometer sunk to bottom. No float at all. Any advice on what this means? Product still looked, smelled and even tasted pretty good. Do I have a batch of O"Douls???

    Thank you,

    Terry Mcg.
     
  2. newmanwell

    newmanwell Active Member

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    Whatever your using to hold the beer for measuring the gravity is it full enough to let the hydrometer to float at whatever the final gravity reading should be? Meaning if the final gravity is 1.010 can the hydrometer sink that far?
     
  3. Tmcg38

    Tmcg38 New Member

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    Thank you Shaun, Thought I had enough in the tube, now that you asked this I am doubting myself. I will try again tom morrow and see what happens.

    Thanks again.
     
  4. oliver

    oliver Well-Known Member

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    i use a plastic graduated cylinder, and i add the hydrometer first, then add the wort, so i don't have to worry about displacement.

    i'm quite impatient, but the hydrometer sample needs to cool down to whatever your hydrometer is calibrated to. Mine says it's calibrated to 60ºF.

    it sounds like you had some good fermentation, i wouldn't worry about it not being alcoholic. Unless you got an accurate reading at the end of the brew day, the latter reading won't mean too much. I usually take a final hydrometer reading once it's ready to drink.
     
  5. jeffpn

    jeffpn Well-Known Member

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    There is a calculator on this website to compensate for temperature differences. The beer doesn't have to be at 60° or 68°, whichever hydrometer you have.
     
  6. EbonHawk

    EbonHawk New Member

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    Just my thoughts. Heavy, dark beers early on (especially right after cooling down to yeast pitching temp) and depending on how much hops and/or suspended proteins (possibly) made it into the final product... it can be tricky to get a good reading.

    My best advice is to just practice measuring different things, see how the hydrometer reacts in different liquids (fruit juices, oj, a sugar solution made with honey or sugar, coffee with or without creamer) and get used to taking readings in different colored liquids and different specific gravities, etc.

    I have my cylinder that I float my hydrometer in, marked with a Sharpie marker at the level where I need to fill any liquid to, to get a good reading at slightly less than 1.000, because some things ferment to that low! So, put your hydrometer in the container and fill it up with distilled water and see how much it takes to make it float well above the bottom, but don't go crazy... you kinda want it at the level where it will measure 0.990 comfortably, with still a little bit of extra room at the bottom. You don't want to just fill it all the way up, because that's just waste unless you like to drink a lot of unfermented beer or syrupy sweet meads and wines.

    Also, once you get your hydrometer floating, it's ALWAYS a good idea to give your hydrometer a good spin or three (like a top) to get everything off of it that you can. Suspended gases and other extras in the wort will cling to the glass and cause some slight deviation in readings. Especially later in a ferment when the warmed up beer starts outgassing and all the bubbles are clinging to it, it can throw your reading off considerably. Just a few good turns usually does it, grasping it between thumb and forefinger and giving it a decent spin. You'll get the hang of it with practice.
     
  7. EbonHawk

    EbonHawk New Member

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  8. GernBlanston

    GernBlanston New Member

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    Minor clarification. Solid fines, yeast, hop bits and particulate matter do not effect the gravity reading of a hydrometer. Only the sugars dissolved into solution.
     
  9. EbonHawk

    EbonHawk New Member

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    Additional clarification... gunk floating in your sample, as well as a goodly supply of dissolved bubbles, will make it more difficult to read, regardless of the actual specific gravity reading.
     
  10. Nosybear

    Nosybear Well-Known Member

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    Fines, yeast, bubbles, gunk, etc. DO affect the gravity reading when they settle on the float. It's likely not enough of a difference to be detected with a standard, 2-degree graduated hydrometer, though. Bubbles in still-fermenting beer will stick to the float and add buoyancy, making your hydrometer read high. Dark beers make it hard to see where the bottom of the meniscus is.... The hydrometer reading is an approximation, as is any measurement, confounded by a bunch of variables you have little or no control over. Don't worry about the +/- 2 degrees any of these factors other than bubbles sticking to the hydrometer - they can throw you off by a lot. Spin the hydrometer in the sample jar to knock those off and you'll be close enough.
     
  11. GernBlanston

    GernBlanston New Member

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    Is that some official engineer lingo?
     
  12. Nosybear

    Nosybear Well-Known Member

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    Yep. It's how we build bridges and blow up rockets.
     

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