Ask The Brewmasters

 View Only

  • 1.  Beer Pint base blow out after production.

    Posted 07-08-2022 09:22
    Dear all,
    After production Beer Pint transfer to WH, few days later found many bottle broken at the bottom.
    We didn't the real root cause yet so far! Kindly indicate the clear root cause and counter measure to prevent this problem happen in the future?

    Thank in advance for tip sharing.

    Kind regards.

    ------------------------------
    Ratny Khiev
    CI Executive
    Vattanac Brewery
    Phnom Penh
    (+855) 088 8777 909
    ------------------------------


  • 2.  RE: Beer Pint base blow out after production.

    Posted 07-08-2022 16:30
    There is not enough information to make an accurate assessment.  I will assume that you are using glass bottles but several questions remain.

    !.  Are the bottles reused glass?
        -If reused are they removed from old cardboard boxes using an in-line saw?
        -If reused are they washed in a hot temperature zone caustic bottle washer?
        -What is the initial temperature of the beer?
        
    2.  Are the filled bottles pasteurized and if so is it a tunnel pasteurizer or sterile filter?

    3.  Where are the bottles manufactured and do you have a quality inspection for new glass identifying flaws, bird swings, blisters, or any abnormalities using go-no go gauges?

    4.  What is the CO2 volume of the beer?

    5.  Glass is glass.  Are your conveyors smooth? Lubricated.

    6. How are the bottles packaged eg end loader, drop packer?

    Can you send photos of the broken bottles.  This would help identify the source.

    Regards
    Jim

    ------------------------------
    James Holden
    Brewing Consultant
    Retired
    jholden007@hotmail.com
    Canada/US/Mexico
    ------------------------------

    Original Message


  • 3.  RE: Beer Pint base blow out after production.

    Posted 07-14-2022 10:51
      |   view attached
    Dear James,
    Thank for your intervention, let see my answer in the yellow as below:
     1. Are the bottles reused glass? No, it is the One Way Glass Bottle.
        -If reused are they removed from old cardboard boxes using an in-line saw?
        -If reused are they washed in a hot temperature zone caustic bottle washer?
        -What is the initial temperature of the beer? Inlet filling bowl 5 oC.
    2.  Are the filled bottles pasteurized and if so is it a tunnel pasteurizer or sterile filter? Yes, It is pasteurized by Tunnel !
    3.  Where are the bottles manufactured and do you have a quality inspection for new glass identifying flaws, bird swings, blisters, or any abnormalities using go-no go gauges? Bottle from OI-BGC-Malaysia, We haven't perform any inspection for the first production of bottle by Supplier either at entrance control for the the above mentioned criterions.  
    4.  What is the CO2 volume of the beer? CO2 volume content from 0.5-0.55 % wt/wt
    5.  Glass is glass.  Are your conveyors smooth? Lubricated? Lubricated conveyor.
    6. How are the bottles packaged eg end loader, drop packer? No uased Drop Packer, Using Vacuum packer, Top Sealer & Manual Paletizer.
    Can you send photos of the broken bottles.  This would help identify the source. kindly see in the attached file.
    Kind regards & Thanks.



    ------------------------------
    Ratny Khiev
    CI Executive
    Vattanac Brewery
    Phnom Penh
    (+855) 088 8777 909
    ------------------------------

    Attachment(s)

    xlsx
    01. Info for bottle breakage.xlsx   278 KB 1 version
    Original Message


  • 4.  RE: Beer Pint base blow out after production.

    Posted 07-14-2022 16:56
    Thanks for the feedback Ratney.  Most craft brewers in the Americas predominantly package in cans so have little experience with glass.  Glass is a whole different experience.

    From your answers what comes to mind is that:
    1. Saw damage or Soaker thermal shock has been eliminated
    2. You use a Tunnel pasteurizer.
    3.  Your glass is not inspected for flaws and weaknesses.
    4.  From the photos the bottom breakage is a very clean break around the circumference 

    Most tunnel pasteurizers have separate temperature zones that 1.  Reduce thermal shock and 2. Achieve a  10 to 15 PU level at a maximum of 600C. (logarithmic calculation)

    Apparently your CO2 solubility in beer is 0.55(g/litre?) or 1.0 Vols.... Which doesn't make sense to this old guy so I will estimate it at 2.70 Vols in the bottle. At 20C that's about 10 PSI(0.7 atm or 70 Kpa)

    But at your Pasteurization Temperature of 600C you might very well be looking at pressures of 40 PSI to 60 PSI (2.7 to 4 atm).  That is a lot of pressure

    My advice.
    1. Get out your micrometers and measure glass thickness above the break all the way up to the shoulder, and below the break.  I suspect that there are thickness deviations from the spec.
    2. Contact your glass manufacturer for all of the bottle specifications including maximum pressures.

    Hope that this helps
    Jim



    ------------------------------
    James Holden
    Brewing Consultant
    Retired but Busy
    jholden007@hotmail.com
    Canada/US/Mexico
    ------------------------------

    Original Message


  • 5.  RE: Beer Pint base blow out after production.

    Posted 07-15-2022 12:08
    Hello Ratney,

    I purchased 12 oz long neck amber beer bottles for personal use many times from the same California retailer.  I started experiencing random breakage at the neck and base in the last two to three years or so and investigated what was going on.

    1. The older bottles (circa 2018/2019 or earlier) weigh 230 grams and are thick at the transitions at the neck and base. These bottles never randomly broke and are very reliable packages.

    2. The newer bottles are 188 grams and are noticeably thinner in these areas and the finish on the neck is not as strong, as they easily chip if mishandled and strike another bottle.  They are also very susceptible to breakage when filled/pressurized if any errant contact occurs to the neck and some have just randomly exploded (not from overpressurization) at the base.  I suspect this is due to either a flaw in the glass, or a strike in this area during cleaning and/or filling, causing a stress point that eventually fails.  NOTE: I examined and weighed several commercial beer bottles from a variety of brewers and found a variety of weights, most were on the 188 gram end of the scale, but with many variations in design. A bottle in the 230 gram range for a standard beer (not a Belgian, for example) was not common.

    3.  I have not found a current supplier of the 230 gram bottles I used to get, and have settled for the 188 gram bottles and the risk of failure.  At my scale, this is a nuisance, at a production scale it is a mess and a big expense as you are experiencing.

    I suggest you proceed as I have and James Holden recommends and investigate the breakage at multiple levels including the supplier, bottle specifications, cleaning/filling/packaging processes, and pre and post-fill handling procedures.

    I hope this helps,

    Harlan Coomes
    Dip.Brew




    Original Message


  • 6.  RE: Beer Pint base blow out after production.

    Posted 07-15-2022 16:53
    The bottles look more like they broke under thermal shock and not excessive pressure, but I would not bet much on that impression. Under excess pressure, bottles usually shatter into big pieces. If the bottles were insufficiently annealed during manufacture, strain could be left at the corner, which is where most of them snapped. Maybe get a sample of bottles from another manufacturer to see if they do better.

    Excess pressure can come from
    *Overcarbonation: The CO2 content you report would be insufficient to raise foam, so it would be good to recheck.
    *Thermal expansion of beer (lowering headspace volume) and increase in CO2 pressure because of Charles Law. This could come to around 3 atm at absolute = 2 atm gauge (30 psig) at 60 C. Worse if there is insufficient headspace (should be about 15 mL at room temp).
    *Escape of CO from solution into headspace. This could happen if there is dust or other bubble nuclei in the bottles or the beer (including glass dust and filter media like DE), or small pits or pores in the glass, or if the conveyor shakes the bottles in or just before the tunnel. This could lead to most of the dissolved gas crowding into around 10 mL of headspace at pressures that will certainly cause the glass to break.

    Roger Barth, Ph.D.
    Emeritus Professor of Chemistry
    West Chester University
    rbarth@wcupa.edu
    Author of
    The Chemistry of Beer: The Science in the Suds.  ISBN 978-1-118-67497-0.
    Mastering Brewing Science: Quality and Production. ISBN 978-1-119-45605-6




    This e-mail message was sent from a retired or emeritus status employee of West Chester University.



    Original Message


  • 7.  RE: Beer Pint base blow out after production.

    Posted 07-15-2022 18:45
    Hi
    Try reaching out to 
    James Hartman
    707-968-1609

    Does a lot of glass analysis as an independent.  Help us ID a small defect in the heel of our bottles that we could go back to the glass manufacturer with.
    Good luck


    Collin Godkin 

    Director of Brewery Operations 

    Full Sail Brewing Company
    KYLA Hard Kombucha
    506 Columbia Street, Hood River, OR 97031 

    Desk:  541-386-4219 

    Cell:    541-490-3940 

    www.fullsailbrewing.com  

    www.kylakombucha.com 



     





    Original Message


  • 8.  RE: Beer Pint base blow out after production.

    Posted 07-15-2022 18:43
    Hello Ratny,

    Based on your pictures you have low-level pressure breaks, meaning that the cause of breakage was low glass strength rather than high stress levels.  This indicates that there is some type of flaw or damage at the fracture origin which is decreasing the strength of the glass.  Insufficient glass thickness is likely not the cause of the failures.  A microscopic examination of the fracture surface would be necessary in order to identify the flaw or damage present.

    The two main areas of a glass bottle near the bottom where a fracture can originate are the inside knuckle (inside surface at the transition of the sidewall to the bottom) and anywhere along the outside bottom surface.  Based on the fractures where the bottom is split in half (creating a "D" shaped piece) the outside surface on the bottom likely contains the fracture origin.  An inside knuckle origin will cause the entire bottom to come off in one piece.

    You will need to have the fractured bottles examined in order to identify the flaw or damage causing the breakage.

    Glass, when under tension stress, exhibits a property referred to as static fatigue which lowers the glass strength over time.  This is why a bottle sitting in the warehouse can suddenly break.  However, an beer that is tunnel pasteurized will typically experience its highest equivalent stress levels while in the pasteurizer.  In this way, a pasteurizer will basically sort out the defective bottles, and any delayed breakage is rare unless the bottles are damaged after exiting the pasteurizer.  Once again, a microscopic examination of the bottles is necessary in order to determine the the flaw or damage present, which is the cause of the breakage.  If you do send the bottles to a lab for this analysis, you likely only need to send the bottom pieces.

    Please let me know if you need additional information.

    Regards,
    Steve

    ------------------------------
    Steve Spence
    Owner
    Missing Links Brewery
    Renfrew PA
    ------------------------------

    Original Message


Related Content