Pro Tip: Here’s how to create a first-class mold control program that will reduce consumer complaints.

The prevention of mold growth on or in bakery products is an important responsibility for bakery plant managers. Mold spores are all around us at all times.

It is the change in atmospheric conditions (heat and humidity) that leads to an increase in mold spore formation and germination. Unfortunately, bakeries often see the result of this in the form of increased consumer complaints. By instituting an aggressive mold control program, you can significantly reduce the number of these complaints.

All departments have a role in this program. Less than standard adherence to facility maintenance, good manufacturing practices, and equipment cleaning and sanitizing will lead to mold development in bakeries and products especially during this warmer time of the year.


What actions can you take from a sanitation perspective?

  1. Self-inspections: Make mold source identification and elimination a key component of your inspection program. One square inch of mold can produce enough airborne spores to contaminate an entire building. Pay particular attention to HVAC unit condensation on drain pans, ductwork, ceiling tiles, damp walls, refrigeration units, cooling tunnels, icing spirals and the undersides of all equipment.
  2. Air handling equipment: Wash and sanitize all air intake and exhaust units after winter’s neglect. This is the No. 1 source of mold spore development and distribution. After a thorough cleaning, determine the proper frequency of future cleanings to keep these units mold-free. Use the finest porosity filtration units possible. Keep in mind that they will clog, if effective, requiring frequent changes. Filter media are available that specifically trap and kill mold spores. Do not “aim” moving air directly at the product. If a mold source exists, you will be “bombarding” the product with mold spores. The same advice pertains to portable fans, which also must be placed on an increased wash and sanitize frequency schedule.
  3. Windows and doors: Exterior windows and doors should be kept closed. This can be a major source of unfiltered air that enters the building. Providing screens satisfies pest control issues but is ineffective in preventing mold spore intrusion. The major area of opportunity in most plants is in shipping and distribution. Overhead doors are to be opened only when a trailer is spotted in the dock.
  4. Equipment cleaning and sanitizing: Slicers and baggers should be washed and sanitized every four weeks or more. Daily sanitizing of hones, felts, air bars, scoops, crumb blowers, etc., will assist in the battle against these “invisible invaders.”
  5. Depanners, cooler conveyors, conveyor brushes, cooler wash tanks, catch cloths, emergency cooling racks, etc., should be placed on a periodic schedule for detergent washing and sanitizing. All equipment from oven discharge through the baggers must be monitored via self-inspection. 
  6. Overheads, floors and drains: Inspect overheads for condensation on pipes and maintain all insulation in like-new condition. Floors and drains should be washed and flood-sanitized weekly. Wash and sanitize all overhead catch pans when cleaning the associated air-handling units.
  7. Exterior conditions: Inspect roof areas for standing water and mold growth. Spray areas of concern with sanitizer in compliance with label directions. Eliminate sources of airborne dust that will clog filters or enter the bakery to contaminate the products. Inspect for sources of condensation due to temperature swings between days and nights. 


How are you addressing the following production concerns when it comes to controlling mold growth? Here are some suggestions that can help. 

  1. Monitoring of pH and total titratable acidity (TTA): The pH and TTA of all products should be controlled to prevent mold growth. The pH and TTA will vary with changes in fermentation and ingredients. The pH and TTA of products should be checked daily by management with particular attention paid to the whole-wheat varieties. Products should not be touched with bare hands. Management needs to ensure employees are practicing frequent hand washing and sanitizing. Proper use of vinyl and latex gloves is required when hand contact with products is necessary. Compressed air should not be used as a cleaning tool near the products.
  2. Bake and wrap temperatures: Post-bake internal temperatures need to be monitored and maintained at 198°F or greater. Bake out is critical on dense and “light” varieties. Product should be wrapped at 95°F to 105°F. If products are packaged above 105°F, condensation will occur, creating ideal moisture levels for mold growth.
  3. Ingredients: Practice first-in, first-out raw material use to prevent microbial development in ingredients. Care should be given to topping components that are applied after the bake.
  4. Finished product staging: All products should be staged until ambient temperature is achieved. Placing warm product on cool or very hot trailers will produce condensation inside the bag/wrapper. Do not place products in direct sunlight.
  5. Slicer oil: Where in use, make sure the oil has sorbic acid listed as a mold inhibiting ingredient.


Are these items included in your preventive maintenance program?

  1. Compressed air: It is critical that your air systems produce clean, dry air. There are many locations within each plant where compressed air comes in direct contact with product components and/or finished products. Any location where this occurs should be equipped with at least 0.3-micron filtration and as close to point of use as possible (in all applications after the oven or fryer). Periodic change (four weeks max) of all filters is required. Periodic flushing (every four weeks) of the compressed air system with atomized quaternary ammonia should be performed as well. 
  2. Air makeup unit service: Provide the “finest” filtration porosity possible while still being able to provide adequate airflow. Balance the building to a “positive” air pressure situation so cooler, filtered air is brought in and heated air is exhausted. Buildings exhibiting “negative” air pressure will bring in unfiltered air through any crack, crevice or opening available. Establish a “spring cleaning” exercise to check, lubricate and repair all air-handling units, in conjunction with sanitation cleaning.
  3. Ductwork: Consider the safe use of UV light applications where ductwork and condenser units are difficult to access and require frequent maintenance and cleaning. This is becoming a popular technology for enclosed areas where the potentially harmful UV light rays can be safely contained.

There are many issues to address regarding controlling mold spore entry and development in bakeries, which in turn, contaminate products. An integrated, aggressive, highly organized strategy must be developed in each bakery location. Is your mold control program world class or second class?

Rowdy Brixey is founder and president of Brixey Engineering Inc.

You can connect with him on LinkedIn.