Dry hop gravity changes

Discussion in 'General Brewing Discussions' started by Mark Farrall, Oct 30, 2018.

  1. Mark Farrall

    Mark Farrall Well-Known Member

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    I've had a Tilt hydrometer for a while now and I've started noticing that when I add my drop hop the gravity drops then slowly climbs it's way back up to a lower level than before the dry hop. Before the tilt I wouldn't have noticed as I wasn't taking samples until the batch was finished.

    For example my current batch hit 1.011 for two days, I added my dry hop and it dropped to 0.993 in around 24 hours. It stayed around that level for about 36 hours and then started climbing gradually. Four days later it's stabilised at 1.002. Same thing happened for the last two batches I've dry hopped.

    I've heard people talking about hops being diastatic, but don't see how that explains a drop and then slow climb back up, just a slow drop. Anyone know what's happening with this?

    Edit: i'm appreciating it (assuming it's fermentation) as the last two batches have been a bit higher than I wanted until the dry hop cleaned it up and I haven't noticed any weird flavours in the beer.
     
  2. oliver

    oliver Well-Known Member

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    why not use a real hydrometer to make sure?
     
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  3. thunderwagn

    thunderwagn Well-Known Member

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    I've listened to a podcast (The Session I think) with Vinnie Cilurzo from Russian River, discuss more fermentation taking place after heaping in the dry hops and sugars from the hops fermenting more. Other brewers would come to him asking if he had ever seen this phenomenon, and he explained what was going on. It's actually a very good podcast. He's got great stories! I'd recommend it. I believe this is it.

    http://www.thebrewingnetwork.com/the-session-russian-river-brewing-company/
     
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  4. Mark Farrall

    Mark Farrall Well-Known Member

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    My batches are too small to do a hydrometer sample other than at the end. Which I do. I calibrate the tilt against the hydrometer using tap water at the begining of each batch.
     
  5. J A

    J A Well-Known Member

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    I'm going to speculate that your gravity isn't changing, at least not drastically. If that were the case there's no reason for it to go back up, not to mention the fact that dry hopping is pretty routine and doesn't result in .9-gravity beers. I suspect that increased nucleation from the particulate introduced in the form of ground up hops is interfering with the way the Tilt measures.
     
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  6. Mark Farrall

    Mark Farrall Well-Known Member

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    That definitely explains the initial large drop and the slow return. Now to work out how much of the remaining difference is due to any hop diastatic power or to bubbles that won't fall off in the time frames I'm prepared to wait.

    I'm going to package in a few days so that final hydrometer reading will be interesting.
     
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  7. okoncentrerad

    okoncentrerad Active Member

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    I've read several times about people whos tilt gone crazy after dry hopping
     
  8. The Brew Mentor

    The Brew Mentor Well-Known Member

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    The Tilt may be a cool toy for some, but @ ~ $135 and a 3 month battery life, it sounds like more trouble than it's worth.
    Another concern is that if you have multiple fermentors going at the same time, how do you easily remove it?
    I'll stick with a Thief and a regular Hydrometer.
    Sorry to derail!
    Brian
     
  9. Nosybear

    Nosybear Well-Known Member

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    I'll stick with my refractometer and correction software! Cross-checking with a hydrometer, I'm within a point of gravity, close enough for me. I agree with some of the posters above: The Tilt looks like a high-tech answer to a simple problem. It's money I'll spend building a recirculation system for my mash tun.
     
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  10. Mark Farrall

    Mark Farrall Well-Known Member

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    Yep it's a toy, but the battery life doesn't worry me, they're cheap and easy to replace and it's better than three months. And it's certainly precise enough to tell me when the batch is done, which is ultimately all I'm relying on it for. The rest of the data is currently just for interest.
     
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  11. Mark Farrall

    Mark Farrall Well-Known Member

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    So for multiple fermenters, they come in eight colours and the app you use will show the data as coming from a particular colour tilt. Then on the site here you say the data coming from your orange tilt is tied to your IPA brew session and it'll store the data on the brew session and the recipe will also show the latest brew session. So you can have up to eight going at once before you hit problems.

    What's the price jump on the pro fermenters that give you the constant readings of gravity, temperature and pH? Is that beyond the size/price of most craft brewers and really only the domain of the macro brewers?

    I was listening to one of the brewers from a craft brewery that's been bought by one of the local macro brewers. One of the first big purchases they got was new fermenters and they live off the data that's constantly coming from them. Their cooling jackets come on automatically when the temperature hits a cutoff (which caused problems when they weren't filling some fermenters completely and triggering the top cooling jacket constantly because it was reading air temperature).
     
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  12. Mark Farrall

    Mark Farrall Well-Known Member

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    Ended up at 1.004, so only a point off where the tilt had settled after the dry hopping.

    Surprised that it dropped around seven points from dry hop. Wonder how much is the hops creating new simple sugars and how much that it's just a bit of rousing..
     
  13. Beer_Pirate

    Beer_Pirate Active Member

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    Fermented beer has some dissolved gas in it. It may be possible that the hop material is introducing nucleation sites for CO2 to come out of solution and grab on to and lifting the tilt ever so slightly. I'd think it's akin to measuring a finished beer with a hydrometer, where the carbonation is going to interfere with a true measurement until you get all of the gas out. Not sure if this was addressed in the (3 hour! :eek:) podcast or not.
     
  14. J A

    J A Well-Known Member

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    It is surprising to see that big a drop but I usually count on at least a couple of points after dry hop. Hops aren't adding sugars in any significant way so it's just residuals getting used up.
     
  15. Nosybear

    Nosybear Well-Known Member

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    I'm tending to agree with the "gas" crowd. Some of the CO2 precipitated out, adhered to the hydrometer and lowered the reading.
     
  16. Mark Farrall

    Mark Farrall Well-Known Member

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    As thunderwagn mentioned It's not the hops adding sugar, it's the hops creating simple sugars. Seems hops have diastatic power and it's now the successor to the diastaticus panic of a few years back. There's concerns about bottle bombs and over-carbonated kegs. It's even got a name, dry hop creep.

    And this dry hop was 4g/L, so probably would make a difference, especially as my mash wasn't that efficient this time.
     
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  17. J A

    J A Well-Known Member

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    Hmmm... Interesting. I'll have to ask around about that and see what my brew friends are seeing. I've never noticed a trend in dry hopped beers being more attenuated. Good research subject.
     
  18. AHarper

    AHarper Well-Known Member

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    Will the SG change by much due to temperature changes? Would the dry Hopping alter the temperature?...
     
  19. Beer_Pirate

    Beer_Pirate Active Member

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    SG itself won't change, but the equipment used to measure SG (on a homebrew scale) is usually calibrated to a specific temperature and the instrument wouldn't show an accurate reading. That being said, dry hopping shouldn't change the temperature of the beer by any appreciable amount, especially after the hop material is dispersed throughout the beer.
     
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  20. Mark Farrall

    Mark Farrall Well-Known Member

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    Dredging up history...

    Same thing happened with the same beer (a kettle sour along the Gose/Berliner Weisse type). A gentle swirl or two of the fermenter popped the gravity back up to where it was prior to the dry hop. Now to see if it drops over the next few days...

    Strangely also dry hopped a session black IPA I had brewing. No change to the gravity readings from the Tilt. I'm assuming different amounts of dissoved gases in the two beers.
     

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