The second mistake: poor process data
The second mistake that food processors make is that they don’t have good systems to record process data and write it to the batch record. Without such a system, the effect of process variables on moisture remains a mystery.
There are three types of process data you need in your batch record: Ingredients, environmental data and machine settings.
We’ll start with ingredients. Do you get a certificate of analysis with moisture content on it from each of your ingredients suppliers? Remember that even if you do, it’s unlikely that this is a useful process variable because of the shortcomings of moisture balances we just talked about. Also, note that if you don’t know the moisture content of what suppliers are sending you, your process could be sabotaged by ingredients that are too wet or too dry.
Incoming ingredients can also refer to pre-drying process steps that may happen in your factory. For example, we have found a clear correlation between meat slice thickness and drying times for beef jerky. Failure to collect that data for each batch is a missed opportunity for drying process improvement.
The second factor that affects your process is your factory’s environment. This includes temperature and vapor pressure, as well as post processing storage steps in which moisture may be gained or lost. Remember that your yield depends on what makes it into the package, not what your moisture was when your product emerged from the dryer.
The third source of data which should be written to your batch record is machine settings. The changes that an operator makes to these machine settings are critical to the drying process. Take a moment and think of the best machine operator in your plant. How does he or she compare with the other operators and staff? How much better is that one individual than the average?
Chances are that person has earned a sterling reputation by successfully running a complex process. He or she changes machine settings whenever necessary to keep the process humming along without a hitch.
What isn’t clear, sometimes even to your superstar operator, is how he or she does it. Parameters like dwell time, steam settings, belt speed, and oven temperature can all be changed, but their correlation to moisture often remains a mystery.
What’s more, even skilled operators may not have the right incentives in place to achieve success. For example, we have visited pet food factories where operators are running at moisture levels that are 50% too low because they’ve been criticized in the past for causing mold issues.
Fixing these mistakes can seem like a daunting task. We at METER Group have spent the last five years building tools for nailing the moisture up every batch you make. Here are our recommendations for making an immediate improvement in your drying methods.