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  • 1.  Mashtun / Kettle after CIP staining

    Posted 01-25-2023 13:09
    Edited by Walter Heeb 01-25-2023 14:49
    Hello,

    I'm having trouble getting our Mashtun and Kettle from staining after CIP.

    ***Update:  The kettle came clean this time but not Mashtun... I ran the jackets on the kettle to heat up the caustic and I think that made a difference.

    I run caustic+hydrogen peroxide booster at 3% for 30 minutes. Then rinse and run phos/nitric acid 3% at 120-130F for 30 minutes.

    I have attached photos.

    Thank you,
    Zach

    ------------------------------
    Zachary Gordon
    Old Thunder Brewing
    Pittsburgh PA
    ------------------------------


  • 2.  RE: Mashtun / Kettle after CIP staining

    Posted 01-26-2023 11:50
    Hello Zach,

    The visuals of the defined liquid level and apparent splash markings above the liquid level (photo 1) appear to be surface metal etching from chemical attack.  On photo No. 2 there is a similar visual, however, appears to be fully affecting a defined area from top to bottom.  How are you introducing your chemicals and is this area in Photos 2 where these chemicals ae being introduced?

    If this issue is etching, then resurfacing the ID would be needed.  If this issue is residual chemical or other media, more aggresive chemical steps may be necessary.

    Feel free to call and discuss.
    Robert Schuck
    Astro Pak
    562.833.6402

    ------------------------------
    Robert Schuck
    Sr. Technical Sales Manager
    Astro Pak
    Costa Mesa CA
    ------------------------------

    Original Message


  • 3.  RE: Mashtun / Kettle after CIP staining

    Posted 01-26-2023 18:59
    I fill the mashtun with water, then dump the chemical through the door on top.

    It's around the entire mashtun though, I don't think its from splashing?

    ------------------------------
    Zachary Gordon
    Old Thunder Brewing
    Pittsburgh PA
    ------------------------------

    Original Message


  • 4.  RE: Mashtun / Kettle after CIP staining

    Posted 01-27-2023 14:22

    I agree the photos look like chemical etching in a pattern of splashing or chemical running down the sides.  Staining is typically something that has become part of the surface of the metal, not a soil or contaminant that can be cleaned with the typical caustic or acid steps.  Staining can be a result of using poor quality caustic with high levels of iron that is then deposited on the metal at high temperature (above 160F) and may then cause more corrosion.  Visually, this looks like a dark, more uniform color.  There is a procedure involving a strong oxidizer to remove this type of stain.  Passivation with a strong nitric acid (not phosphoric) is the best way to remove iron and some corrosion product.  Your pictures, however, look like the metal has been bleached.  My experience is that hydrogen peroxide can be very aggressive to stainless steel and one must be very careful about how it is used.  Heat really accelerates attack on stainless.  I recommend that no heat is added to the system after the H2O2 is added. If the sides of the tank are hot and allowed to dry or if heat is added by a steam jacket, the surface temperature can be much higher than the temperature of the water and cause attack.  It seems some of the brewhouse stainless steel arrives with a lower level of polish and even grade of stainless than one would see in the cellar or in the dairy industry.  This might make it more susceptible to attack as well.  Once the metal has been attacked, it is almost impossible to have a uniform look again without a strong oxidizing chemical (not recommended) or manually polishing.  The good news is that it will not affect cleaning or the beer.

     

    Mike Willis

    Northern California Territory Manager

    Certified Water Technologist

    Chemco Products Company

    1992 Rockefeller Dr. #800

    Ceres, CA 95307

    Office: 1.209.556.1222 x277

    Cell: 925.642.6901

    40@chemcoprod.com

    www.chemcoprod.com

     

     

    Leading the world to a cleaner safer place through unparalleled customer service one client at a time.

     

     




    Original Message


  • 5.  RE: Mashtun / Kettle after CIP staining

    Posted 01-27-2023 14:23
    You may want to manually clean an area accessible from the manway using a brush and rinsing with a hose to determine if your cleaning chemistry works.  That appears to be the type of residue that should be easy to remove, especially given the vessel.

    ------------------------------
    Ashton Lewis
    Manager of Training and Technical Support
    BSG Craftbrewing
    MBAA District Great Plains, Technical Chair
    Springfield, Missouri
    (417) 830-2337
    ------------------------------

    Original Message


  • 6.  RE: Mashtun / Kettle after CIP staining

    Posted 01-26-2023 16:24
    Hey Zach,

    I was having similar issues at a previous brewery I worked at. I was able to narrow it down to caustic scorching, especially right on the jacket. I switched over to non caustic alkaline cycles, running on the high temperature end for those chems, for cleaning my hot side and it seemed to completely eliminate future build up. I did have to do some aggressive acid cycles to remove the staining and run a few passivation cycles. Seemed to work for me!

    Hope this helps.

    Chris Munda
    Head Brewer
    Barrels and Bottles
    Golden, CO

    ------------------------------
    Chris Munda
    Head Brewer
    Barrels and Bottles
    Golden CO
    (719) 209-8595
    ------------------------------

    Original Message


  • 7.  RE: Mashtun / Kettle after CIP staining

    Posted 01-26-2023 19:00
    What acid % did you run to remove the staining?

    ------------------------------
    Zachary Gordon
    Old Thunder Brewing
    Pittsburgh PA
    ------------------------------

    Original Message


  • 8.  RE: Mashtun / Kettle after CIP staining

    Posted 01-27-2023 14:22
    I was running upwards of 6% phos/nite blend. It was also a product from DeLaval that is a "One Step" Acid cleaner. Great product, they advertise it as product that also can take care of light organic soil as well. 
    Another suggestion to prevent this kind of build up in the future Dana from Birko wrote a great article about a "ned" or different method of passivation that has worked wonders for me, haven't gone back since I read this.

    An Improved Stainless Steel Passivation Technique | Birko Corp

    Cheers!

    ------------------------------
    Chris Munda
    Head Brewer
    Barrels and Bottles
    Golden CO
    chrisbarrelsandbottles@gmail.com
    (719) 209-8595
    ------------------------------

    Original Message


  • 9.  RE: Mashtun / Kettle after CIP staining

    Posted 01-27-2023 16:05
    Chris Munda also said it, but I'd switch to a non-caustic alkaline cleaner. We use PBW from 5-Star and it works great. The hotter the better. Requires a rinse, and an Acid #5 wash. We've never had any problems with our stainless.

    ------------------------------
    Mike Frizzelle
    Head Brewer
    Able Ebenezer Brewing Company
    Merrimack NH
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    Original Message


  • 10.  RE: Mashtun / Kettle after CIP staining

    Posted 02-02-2023 21:08
    The problem could be a number of things.  My first guess would be along with some of the others that the method of dosing the chemicals results in concentrated chemicals contacting the still hot surfaces of the vessel and cause staining.  Peroxide on hot surfaces generally produces a blueish stain, but this is not apparent here. I have seen inferior grade caustic products produce staining, but this would be then throughout the vessel and not just above a certain level. It could also be that you have mechanical problems from your sprayball.  If you run your pressure too high, water can atomize and the resulting lack of water film thickness on the vessel can lead to deposits remaining.

    The 3% acid seems extremely high for brewhouse vessels. I also do not see no need to run the acid at such a high temperature. It will clean the same ambient.

    Have you tried if the stains wipe off before the rinse? Use a soft cloth and see if the deposit wipes off.  If it does wipe off, you have proof that the problem is fluid mechanical. 

    If these are in fact chemical stains, run a strong passivation ambient through your vessel to remove the stains.  I would recommend 15 - 20% Nitric Acid ambient for at least 90 minutes.  Repeat if necessary unless all stains are gone.  Assuming that the first run made a difference, off course.

    Cheers,  



    ------------------------------
    Dirk Loeffler
    Loeffler Hygiene & Safety Solutions
    (404) 229-7583
    loeffler.dirk@loefflerhygiene.com
    ------------------------------

    Original Message


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