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Thread: Small Brewery Process Controls (SPC and QC)

  1. #1
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    Small Brewery Process Controls (SPC and QC)

    I am starting to work with a new very small brewery near my house to work on quality checks and process controls.

    My background has been in Industrial Engineering, Process Improvement, and I currently work as a Quality Engineer in a different industry.
    My understanding of brewing comes a lot from research I've done during my time as a homebrewer.

    When looking up quality I of course only see people talking about microbial lab work and sensory analysis. These of course will be implemented in the brewery. Just needing to reallocate room.

    But from my background I'm sure there is a lot more process controls that can be put in place to create consistency in the wort going into the fermenters... But I can't find any real discussion or articles about actual process controls.

    Does anyone have any advice on where to look into the processes for control either using something like SPC or important in process QC checkpoints.

    I was thinking of the milling process because I know that unevenly crushed malt can affect the extraction from the grains so I was thinking that Statistical Process Control (SPC) on the milling machine may be helpful to identify when the process is starting to go out to know to either adjust the gap or do other maintenance.

    I have found some studies where SPC control charts were used for tracking IBUs over many batches for big breweries. I don't think that would help here though.

  2. #2
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    Alright... I know that first post was very open ended... Which makes it difficult to really respond to and asking for a lot of information without putting in the initial effort.

    So I will try to expound on what I'm specifically wanting to know.

    Starting off with what I mentioned in the OP.

    I know that different crushes of the malt will affect the extraction and conversion in the mash. How do other breweries control the milling? Is there just a maintenance schedule for the mill, regular cleaning and checking the gap?
    In my day job we "qualify" the processes. Use SPC control charts. Perform regular tests on the machine or process and recording the data on the control charts. We have control limits, spec limits so we know when steps need to be taken to make sure the process stays in control.
    -Would there be any benefit to using this for milling? Regularly mill a small quantity of grain and either take measurements of how the grain is broken up or do something like the malt sensory analysis to get a standard extraction data point.


    A big QC area I know is packaging. Tracking DO and fill levels is important for both canning and bottling lines... But what checks and controls are useful on kegging lines? The brewery I'll be working with only does onsite sales currently, with eventually limited distribution expected. So the storage and sales will generally be structured. But what is really measurable at these points.
    Maybe something with keg cleaning? Time and thoroughness? Is DO and fill levels still important to track?


    For mashing I know that data collection is common. People record pH, temperature, and more. But other than taking immediate action like to adjust the temperature or pH or being able to look back to see what went wrong when a beer doesn't turn out right what kind of controls do people put in place with these?
    What actual QC checks are performed during or after the mashing? I know of the iodine starch conversion test which appears to be the most common way of knowing the mash is done.

    Would tracking lautering time be useful information? Working on the processes to speed it up?

  3. #3
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    Considerations.....

    Pantego Texas hahaha. That one is good for a laugh. I have to wonder what became of the Ridiculous Police department in that place.....
    Brewing is more Art than Science, a lot more in fact. Those who are attempting to turn this equation the other way round are both asking for problems and trying to reinvent the wheel.
    What needs to be stressed is that its critical to have a baseline operating procedure that is time tested and produces consistent results before all manner of extremely detailed analyses are invoked. What this really means is some serious time working the craft using methods that are industry proven.
    Deviation from doing things the same way by one person on the staff can create problems. Microbreweries can and do attract people who both do and do not have a talent for the work. Its a craft that some are drawn to for the wrong reasons.

    This type of thing would seem to only be practical in larger scale operations.
    If you are running a can seamer, there is a device called " Clearance Gauge " that I would consider a must for such an operation if you have a large capacity canner.
    Warren Turner
    Industrial Engineering Technician
    HVACR-Electrical Systems Specialist
    Moab Brewery
    " No Cell Phone Zone."

  4. #4
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    Quote Originally Posted by Starcat View Post
    Pantego Texas hahaha. That one is good for a laugh. I have to wonder what became of the Ridiculous Police department in that place.....
    Brewing is more Art than Science, a lot more in fact. Those who are attempting to turn this equation the other way round are both asking for problems and trying to reinvent the wheel.
    What needs to be stressed is that its critical to have a baseline operating procedure that is time tested and produces consistent results before all manner of extremely detailed analyses are invoked. What this really means is some serious time working the craft using methods that are industry proven.
    Deviation from doing things the same way by one person on the staff can create problems. Microbreweries can and do attract people who both do and do not have a talent for the work. Its a craft that some are drawn to for the wrong reasons.

    This type of thing would seem to only be practical in larger scale operations.
    If you are running a can seamer, there is a device called " Clearance Gauge " that I would consider a must for such an operation if you have a large capacity canner.

    Yes brewing is an art. I have heard recipe formulation described like composing music. Base malt being the drums, specialty malts like the rhythm lines, hops are the melody.

    But the production of beer is fully based in the science. It is industrial processes as well as artistic endeavors.

    Flow painting is absolutely an art but it is entirely dictated by fluid dynamics. Understanding the science of fluid dynamics coupled with an understanding of the art creativity can be very helpful.

    I am NOT trying to overly add in "extremely detailed analyses". There are MANY tools to use for controlling processes. I am not only talking about SPC. I am not looking to do stuff like Six Sigma process capability analyses.

    Adding controls of processes can be very simple. My understanding is that most (all) brewers control the mashing process in part by maintaining temperature, controlling PH, and water treatments. How much tracking is done of these though? Is PH taken every 5-10-15 minutes and adjusted constantly? Do people track all the data acquired by this?
    Are there any other controls people use?

    How do people maintain consistency in extraction efficiency? Is there anything more than milling consistency and the PH, Temperature, minerals?
    Also again with the milling how is it maintained? Do people just have a set schedule for cleaning and maintenance?
    Do people just wait for a problem to occur?
    Do breweries change the mill gap for every malt, for instance I believe the Maris Otter kernels may be a little smaller than the base malt the brewery uses.

    As I said, I am looking for the basic controls that breweries find useful for maintaining consistency. Any analysis can be looked into further down the line.

  5. #5
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    As far as milling is concerned, I have never used SPC, but that is no reason not to. The critical factors are runoff time and extract. So back calculating extract efficiency on every brew is a quick calculation and the result is SPC'able if you really want to. You could do time as well, though if it is manually controlled, you are probably not going to get anything meaningful. I would be tempted to use a cusum chart as fist step for these. To do anything with the grist as such, you would need a decent shaker set up - doesn't have to be a machine, you can make up hand sieves - perhaps even buy them, and then look at the results for each sieve. But again although all sorts of figures about grist ratios are spouted in the brewing texts, what it all boils down to is runoff time and extract. And there are so many variables in mashing and lautering, that you will have to consider accuracy of grist weight and composition liquor volumes, liquor treatment, mash in times, temperatures, sparge volumes, times and temperatures, and the materials you use in the grist. If you are making loads of different brews and each has a different grist, then each of those grists will have to have a different set of SPC charts for accurate analysis.

    Unless you have a really comprehensive MIS then I suspect you will struggle to get anything meaningful.

    If you want to use SPC, then have a look at a few in package analyses first, and then if you have wide variation at the end, you start working backwards with the investigations.
    dick

  6. #6
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    SPC can be applied to the whole brewery and it should be. To everyone that says its just an art, and thats the end of it, I hope you never have issues with any equipment or ingredients.

    The hardest part of applying SPC to the process will be identifying the best point of measurement that would tell you when a process is headed to be out of spec. For the mill, the easiest place is going to be the preboil gravity of the kettle. Any deviation, assuming the malts have not changed in their values, would be an indication of the gap falling out of spec. That said, if you loose efficiency due to an improperly adjusted mill, you are waiting too long to service it. They shouldn't have too long of interval between service, whether its cleaning or maintenance. We use a set of self made go, no-go guages to check the mill.

    A better place to look at for control is in the raw ingredient COA, small changes there may have little effect in the final product, but figuring out how big of deviation will net an unwanted result would be good. The other is yeast performance. Looking at temperature variations, but more closely variation in pitch rate, cell count of active ferment wort, fermentation time and lag time would all be points to look at to indicate if the yeast is struggling or should be dumped and not repitched.

    The engineer in me says go to town and have fun, you will figure out where the balance between trying to control it too much and not enough is. Just remember, its a living thing, so theres only so many ways you can constrain it and given enough time, it will find a way to still not work right. Brewing consisently is 100% science. Brewing something that tastes good is the art.

  7. #7
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    Thank you very much for your insight.

    I also talked with a friend that brews at the most established local brewery to get a better understanding of what they do.

    I definitely have a better understanding of where to start working here.

    I've started looking into the sieves to track the milling process. I also previously talked with the owner/brewer about really getting familiar with the raw material analysis. He gets his bags from a local home brew shop so I don't think ever thought to ask about that.

    I'm still trying to figure out what to do about the kegging process. I don't expect any canning or bottling line. Draught only in the taproom and limited distribution.

    But other than making sure the kegs are cleaned what kind of actual quality checks do people make in the kegging process to make sure that there's no inconsistency or problems introduced there?

    Clean and purge the kegs before filling? Is that it? Should I work to DO checks for this limited distribution path? Are there checks for the actual sanitation of the kegs? I assume ATP testers won't really work because the kegs are sealed so can't get a swab in.

    Sent from my moto x4 using Tapatalk

  8. #8
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    Crash course for new QA/QC persons...

    Read Mary Pelllettieri's excellent book: Quality Management and Charles Bamforth's book: Standards of Brewing. So many of your questions are answered there. Nothing in those books that you don't need to understand. For starters, I'd say that malt crush should be toward the last thing on your list.
    Phillip Kelm--Palau Brewing Company Manager--

  9. #9
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    Quote Originally Posted by gitchegumee View Post
    Read Mary Pelllettieri's excellent book: Quality Management and Charles Bamforth's book: Standards of Brewing. So many of your questions are answered there. Nothing in those books that you don't need to understand. For starters, I'd say that malt crush should be toward the last thing on your list.
    I have the Quality Management for Breweries book. It was good information. The first many sections are about the definition of quality, governance, and quality manuals then it goes into the FMEA process and basically just says to use that to figure out what needs to be checked and controlled.

    Then there is a lot of information about setting up labs and doing labwork, and sensory analysis. That's great information and I'll be doing it but that's not all that I want to do.

    I'll reread the packaging section.

    But it seems to really just talk about canning and bottling. I'm trying to figure out what from it can and should be applied to kegging for limited distribution.

    Other than the microbiological and sensory analysis sections the book really didn't seem to provide information about what is actually checked anywhere.

    So that's why I came here to try to figure out what breweries are actually doing. What they are tracking in the different processes and what they are using to control either to fix problems before they occur or quarantine and try to fix or dump product so it doesn't get to the customer.

    Sent from my moto x4 using Tapatalk

  10. #10
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    Sterile sampling techniques...

    There are techniques to sample from tanks and kegs that are aseptic. Standards of Brewing outlines some of these.

    There are lots of variables in the brewery. Sieve analysis on malt crush may be easy, but what can you do with a simple 2-roll mill to change the crush? Not much. If you're in a large brewery with a more sophisticated mill, then yield optimization could be warranted. But there is so much more that impacts beer quality. IMO, a fledgling QA program can start with yeast viability and pitch rates to obtain the desired fermentation profile. That might have more to do with final beer quality than most things.

    Monitoring for bugs from the heat exchanger/fermenter/filter/BBT and package to track sources of contamination would be useful. If you suspect packaging isn't perfect, there are efficacy tests for cleaners and sanitizers. Your chemical supplier should have those. I'm not usually too worried about DO in kegged beer.

    If you don't have one yet, then a good PM program is essential to maintaining consistency. Having quality and consistent compressed air, CO2, steam, electrical, and water utilities will also affect beer quality more than many other things you could do.

    Likewise SOPs, records, and the systematic review of those records are other keys to consistency and quality. The only way I see to control a process is to measure it properly. So be sure you have a calibration program for your pH meter and temperature monitoring.

    Point being that you can easily overthink one small item at the expense of large ones.
    Phillip Kelm--Palau Brewing Company Manager--

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