Soft-serve machines can dispense ice cream, frozen custard, sorbets and frozen yogurt. This equipment is common in frozen yogurt shops, ice cream stands, cafeterias, delicatessens, bakery/cafes, and quick-service restaurants to name a few.
To create frozen treats such as ice cream or yogurt, operators pour a liquid mix into a hopper and then prime the freezing cylinder according to the manufacturer's instructions. After initiating the freezing cycle, operators can typically serve the product in less than 10 minutes. Foodservice staff members hold a cup or cone under the dispensing door and pull a handle to release the product.
Gravity feeds the soft-serve product to the freezing cylinder in some units, while others use a pressurized system. With gravity systems, the mix is stored and refrigerated in the hopper located on the top of the freezer. A mix feed is then placed in the opening that connects the hopper and the cylinder. Mix is pulled by gravity into the freezing cylinder through the bottom of the mix feed tube, as air is drawn in through the top of the tube. Once in the cylinder, a beater shaft blends the air into the mix. When the product is frozen and ready for dispensing, the auger on the beater shaft pushes the product out of the cylinder.
Pressurized units freeze the mix the same way as gravity machines once the mix and air enter the cylinder. Unlike gravity units, pressurized machines use a mix transfer system that pumps mix from a container located in a refrigerated compartment below the cylinders up to the cylinders. Metered air is incorporated into the liquid mix as the mix moves up to the cylinder.
Overrun, or the amount of air introduced into the product, differs with these two types of systems. While gravity systems typically run at 42 percent overrun, pressurized units run at 60 percent. The greater the overrun, the higher the profit. Pressurized units can more accurately control the ratio of air to the product.
Some units are viscosity controlled, while others use temperature controls. Operations serving a variety of frozen treats should consider a viscosity-controlled unit, which provides the flexibility to serve different products without technical adjustments to the equipment.
When selecting an ice cream machine, operators must first evaluate the menu to see what items will contain soft-serve ice cream. Serving sizes, number of flavors and types of ice cream also need to be taken into consideration.
Product mix also will dictate the type of machine a foodservice operator should purchase. The freezing cylinder size is one indication of the frozen product capacity. If an operation offers hand-blended milkshakes from a soft-serve machine, a larger freezing cylinder will be necessary to accommodate the milkshake's average serving size. If cones are the only frozen dessert on the menu, a smaller-sized barrel will be adequate. A medium-sized freezing cylinder or combination unit can handle milkshake and cone production. Operations offering two soft-serve flavors may need a twist model that can combine flavors. Restaurants with banana splits on the menu typically require larger units.
One common mistake foodservice operators make is choosing an ice cream machine based on the space they have allotted. Instead, it's important to choose a unit based on the amount of product that operation anticipates serving. Estimating an average head count per day, while also looking at the number of seats and menu items, can help determine the appropriate unit size. For capacity considerations, it is important to know the location's traffic well enough to predict if a high-volume situation may happen more than once each day.
Ice cream machine capacities range from 3.5 gallons per hour or roughly 100 3.5-ounce or 100-gram servings per hour to twist units that provide 15 gallons per hour or about 425 3.5-ounce or 100-gram servings per hour per side. There also is a unit that produces up to 50 gallons per hour. Force freeze timers add capacity to machines.
Higher volume operations or those offering a variety of flavors should consider incorporating a batch freezer to store product. These units produce hard ice cream and are available in a variety of sizes. Batch freezers are typically used for high overrun ice cream, low overrun ice cream, Italian ice, sorbet, gelato and sherbet.
Operators should determine the space available for an ice cream machine. There has been much development in reducing the size of these units, while increasing the capacity. Floor and countertop units are available, and some models offer a narrow profile for tight spaces. Footprints range from 157/8 inches by 24¼ inches to 26 inches by 361/2 inches. Operators should keep in mind that adequate air clearance is necessary for air-cooled units.
Evaluate refrigeration systems by the heat removal capability or BTUs per hour. When selecting an ice cream machine, foodservice operators should be aware that compressors could have the same horsepower rating, but have different heat removal capabilities.
Operators should keep in mind that the electrical service at the location must have enough amperage to handle the equipment. Most soft-serve equipment is nominally 220 volt, and typically available in either single or three phase.
Higher volume operations may want to consider heat treatment soft-serve equipment that only has to be disassembled and cleaned once every 14 days. This saves labor in terms of cleaning time, while also conserving water and chemicals.
When specifying ice cream machines, foodservice operators can choose from a number of options. Popular additions include night switches, cup and cone dispensers, bottle racks for flavors, and syrup topping rails. Foodservice operators can use carts to convert counter-style machines to free-standing units.
Some units provide controls that offer product safety lockouts if the product in the equipment exceeds safe food temperatures. Other ice cream machines have remote monitoring capabilities.
Foodservice operations touting branded product with units in the front of house can select a machine with a wrap around, which merchandises frozen dessert items.
From a food safety standpoint, there has been increased interest in ice cream machines that heat treat the mix to kill bacteria.
When specifying ice cream machines, it is important to be aware of the cleaning and maintenance considerations that these units require. Along with the information below, it is important to follow manufacturer recommendations so as not to compromise food safety.
Certain local health departments require daily cleaning of conventional soft-serve equipment, but it is generally recommended that foodservice staff disassemble and clean these units no less than twice a week.
Some manufacturers recommend replacing all 'O' rings and seals every three to six months. It's important to have these checked periodically for tears or breaches.
If the refrigeration system runs longer than normal on the initial freeze down in the morning, that may be a signal to change the scraper blades, clean the condenser or request a service call.
Clean condensers on air-cooled units at least once a month to eliminate buildup of dust, lint and debris.
Water-cooled units require the water to be checked regularly.
It is important to regularly change ice cream machine scraper blades. If these are not in decent condition, the blades will leave a film of frozen product on the unit's cylinder walls. This buildup can compromise the machine's operation by producing longer freeze times and negatively impacting the unit's energy efficiency.