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Thread: Gelatinisation

  1. #1
    Join Date
    Jul 2009
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    The Netherlands
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    Gelatinisation

    When I'am brewing a Imp Stout ( 26 pl OG ) or other heavy stout, I have allways problems with gelatinisation when filtering.
    All the other beerstyle's no problem, only the IRS
    I maisch 716 pounds in 212 gallons and my lauterton is to small.
    I use a lot off caramelmalts en dark malts.
    I used every kind maischschedule, nothing helps
    Have somebody idea what i can do ??

    Cheers,
    Kees

  2. #2
    Join Date
    Sep 2005
    Location
    Louisville, KY
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    673
    Have you calibrated your thermometers lately? How are you mixing the mash, rakes or by hand? What is your strike temp? Could you have hot spots in your mash? Imp Stout is a large mash, do you have any other beers that have as large of a mash?
    Joel Halbleib
    CBO "Chief Brewing Officer" / Zymurgist
    Bluegrass Brewing Co
    636 East Main St
    Louisville, KY
    www.bluegrassbrewing.com

  3. #3
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    Jul 2009
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    The Netherlands
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    Hi Lou,

    My Thermometers are good, I mash in with rakes, and have no spots in the masch. The strike temp is between 104 > 149 F I have tried everything.
    The IRS is my haviest beer and with that beer I got the problem.
    When I brewing a Barley wine, just with pale and some caramel malts, there no problem.

    Cheers,
    Kees

  4. #4
    Join Date
    Jun 2010
    Location
    Edinburgh, Scotland
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    69
    Hey Kees,

    In your imperial stout, how much pale malt do you use? Also, when you make your barley wine, do you use the same amount of malt (~700 lbs)? With a grist load that big, you could be overloading your lauter tun. To much of a pressure difference (to thick of a bed) can plug it up. Any chance you could measure the diameter of the lauter tun?
    Roger Greene

  5. #5
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    Jul 2009
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    The Netherlands
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    Hi Roger,

    I think the diameter of the lauterton is 1.30 m, and for the big bers I brew to small. I use for Imp Stout 200 kg pale and for the barley 275.
    Other malts in the Imp stout are, bisquit, caramel 120, caramel 300 and alot off carafa spec 1 & 2

    Kees

  6. #6
    Join Date
    Jun 2010
    Location
    Edinburgh, Scotland
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    So, here is what I am thinking, with dry milled grain, the recommended loading of your lauter tun is ~140-175 kg/(m^2) (numbers from Technology Brewing and Malting, W. Kunze). If my calculations are correct, you have about 240 kg/(m^2). With the large mash size plus the amount of darker malts being used, I think this could lead to a slow filter. I would try to make the same beer, but cut down on the mash size and be sure to mill the darker malts mixed in with the pale.
    Roger Greene

  7. #7
    Join Date
    May 2004
    Location
    St. John's, Newfoundland, Canada
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    802
    Quote Originally Posted by bubone
    Hi Roger,
    I use for Imp Stout 200 kg pale and for the barley 275.

    Kees
    Sorry. I don't understand.

    Are you using 275 kg of raw barley in your mash for this beer?

    Trying to help...

    Pax.

    Liam
    Liam McKenna
    www.yellowbellybrewery.com

  8. #8
    Join Date
    Jan 2006
    Location
    Lawrence, KS
    Posts
    216

    imp stout

    We have found that with our larger mash bills, particularly those with roast malts, it helps to use the rakes as little as possible. It is also possible that you could try milling your roasted malts a little coarser as they tend to shatter and create more fines in the mash that could be slowing the runoff
    Steve Bradt
    Free State Brewing Co.
    Lawrence, KS

  9. #9
    Join Date
    Jul 2009
    Location
    The Netherlands
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    No Liam,

    I don't use raw barley, hell no !
    That will give big problem.
    First I used raw oatflakes, never again !

    Kees

  10. #10
    Join Date
    May 2004
    Location
    St. John's, Newfoundland, Canada
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    802
    Not knowing your grist load, I might suggest a few things.

    Water - ensure sufficient calcium.

    Mashing temps.

    I would avoid beta glucanase rest (~100 F).

    A short Betaglucan rest can be good if using undermodified malts/raw grains, but letting it go on too long will lead to viscosity problems with runoff/lautering. A betaglucanase rest will help free the starch for saccharification (with under modified malts) but will also 'free' beta glucans which can bring havoc to your runoff.

    I would suggest (if you can step mash) a twenty minute protein rest at 48-50 C (~120F) followed by a 45 minute saccharification rest at 63-68C (~145-155)(or until iodine -ve). Temp of saccharification rest will depend on the type of mouthfeel/body you are looking for.

    All of this, of course, depends on your use of well modified malts.

    Good luck.

    Pax.

    Liam
    Liam McKenna
    www.yellowbellybrewery.com

  11. #11
    Join Date
    Jun 2010
    Location
    Edinburgh, Scotland
    Posts
    69
    Quote Originally Posted by liammckenna

    A short Betaglucan rest can be good if using undermodified malts/raw grains, but letting it go on too long will lead to viscosity problems with runoff/lautering. A betaglucanase rest will help free the starch for saccharification (with under modified malts) but will also 'free' beta glucans which can bring havoc to your runoff.
    Watch out with this, a beta-glucan rest might not be need with well modified malt, but the enzyme that frees beta-glucans (beta-glucan solubilase) remains active at higher temperatures, with an optimum at ~60C and inactivation at ~70C. With the beta-glucanase having an optimum at ~40C and inactivation at ~60C there is always going to be beta-glucans released that are not broken down.
    Roger Greene

  12. #12
    Join Date
    Feb 2011
    Posts
    22
    Quote Originally Posted by Roger Greene
    So, here is what I am thinking, with dry milled grain, the recommended loading of your lauter tun is ~140-175 kg/(m^2) (numbers from Technology Brewing and Malting, W. Kunze). If my calculations are correct, you have about 240 kg/(m^2). With the large mash size plus the amount of darker malts being used, I think this could lead to a slow filter. I would try to make the same beer, but cut down on the mash size and be sure to mill the darker malts mixed in with the pale.
    I'm not pro, but first thing that came to my mind is exactly what Roger wrote. Also have in mind that roasted malts have more fragile husks and milling can "help" to your problems...

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