How Clean is Your Ice?

The ice machine is a crucial piece of equipment in foodservice, but it can easily become the dirtiest place in the restaurant. The culprits are biofilm, or slime, and scale, which is calcium and magnesium buildup. Ice is food, so pizzeria owners need to make sure the ice maker works and is clean. 

“If the machine is making ice the maintenance is overlooked,” says Rodd Burger, director of technical support for Hoshizaki America, Inc. “That’s the tendency, but the machine is going to fail at the worst possible time.” 

Burger recommends having a professional clean the ice machine at least once a year. Pizzerias should schedule more frequent service, because airborne flour and yeast can get into the equipment. Although a restaurant manager or other employee can perform certain tasks regularly, such as wiping the exterior of the machine, the work of descaling and sanitizing is typically performed by someone who knows where to pour chemicals and how to toggle the various switches and valves. 

For owners or managers that want to perform the tasks, Hoshizaki offers a tutorial and instructional video on its website. “Make sure it gets done,” Burger says. “The last thing you want to worry about is if you’ve got ice or not.” 

Keeping the ice machine clean is a two-part process. Descaling is ridding the machine of the minerals that build up on components, which can impede the movement of the parts and cause premature wear. “Descaling is important because scale is very hard and creates an uneven surface that can host colonies of microscopic bacteria, known as biofilm,” says Aaron Brix, director of product management for Welbilt – Manitowoc Ice. Sanitizing gets rid of biofilm, or slime. 

The specific cleaning instructions will vary according to the machine’s software and other features of the machine. Some machines have a display screen with prompts, and some have certain automated features. 

Descaling 

There are several ways to tell whether the ice machine needs to be descaled. “One common sign of scale buildup is when ice sticks to the evaporator and doesn’t harvest,” Brix says. “Let the ice melt and fall off of the evaporator and clean the evaporator with a soft brush and an approved descaler.” 

Turn the machine off, harvest any remaining ice from the evaporator, and remove the ice from the bin. Ice machines have a “clean” button to start the clean cycle. One common error, Brix says, is people forget to add the proper chemical, or they add it too early, and the chemical gets purged before the machine starts the wash cycle. 

After the descaling cycle is complete, remove all interior food zone components, soak them and scrub them with a soft brush to remove any remaining scale. Rinse the parts with clean water, and descale the ice bin and rinse with clean water. “Never use a blade or a screwdriver to remove scale,” Brix says. “This can ruin the evaporator or gouge the plastic components, which creates an ideal space for biofilm to take root.” 

Sanitizing 

Next comes the sanitizing step, which entails placing the removed components in a solution of water and sanitizer. Let the parts air dry, and do not submerge electrical components. Also, take a spray bottle with the diluted sanitizer and spray the internal food zone of the ice machine and bin. “Again, do not dry,” Brix says. “Let the sanitizer do its work.” Reinstall the food zone components, and wait 20 minutes to let the sanitizer disinfect. Then press the clean button, add the appropriate amount of sanitizer to the ice machine’s water tray, and close and secure the ice machine so it can complete the sanitization cycle and automatically return to the ice making mode.  

Brix notes that larger operators, such as chains and franchises, often have a maintenance team to handle these tasks. They might also have a contract with the company that installed the machine to send a servicing technician on a regular schedule. If the ice machine is on the beverage dispenser, the beverage company might handle the cleanings. Still, it is possible to do the cleaning in-house. “NSF requires commercial ice machine manufacturers to print cleaning instructions on the inside of the front panel of the ice machine,” he says. “So there’s no reason that any employee, regardless of skill level, wouldn’t be able to perform a cleaning cycle on an ice machine.” 

Some operators might be unaware that they need to clean the ice machine, because they have a misconception that the cold temperature will prevent the growth of gross organisms. “But if you’ve ever cleaned a freezer or refrigerator,” Brix says, “you know that’s not the case.” 

Other tips

Green or pink slime indicates the ice machine needs sanitizing. “You’ll see that in the ice bin,” says Dan Bendall, principal at FoodStrategy, Inc. in Rockville, Maryland. “If you touch the sides, you feel the slime.” 

Bendall recommends descaling more often if the area has hard water, which means it has a higher mineral content. The water supplier, such as the municipality, can provide information about water hardness. A filter connected to the pipe can help limit the buildup of minerals. Replace the filter when needed. Follow the manufacturer’s guidelines, such as changing the filter when an indicator light comes on or lines on the filter change color. 

 Close the lid if the ice machine is in a food prep area, to further limit the amount of flour and yeast – which, Bendall points out, is a living organism – entering the machine. Train employees to gather ice with a scoop, not a glass that can break, and especially not with their hands. Wash the scoop, and the tray it rests on, daily in the dishwasher.

Finally, do not let anyone put their food or beverage in the ice machine. “If the health department comes through and they see a can of Coke stuck in there, they will stop service and have you empty the ice machine right away, not at the end of the shift,” Bendall says. “That could put a real damper on the meal period.”

Nora Caley is a freelance writer who covers small business, finance and lifestyle topics.