Types: Soft serve is a type of ice cream or frozen desert, such as yoghurt, custard, sorbet, that hasn't been hard frozen.
Soft serve machines add air to the ice cream mix, increasing its volume by up to 45%. The combination of higher temperature (around 18º F) and more air gives the ice cream a creamier consistency and makes it easy to dispense.
The amount of air in soft-serve ice cream is called overrun. A soft-serve product with a 35% overrun has 35% air mixed into the liquid mixture as it freezes, so one 1 gallon of ice cream mix will yield 1.35 gallons of soft-serve ice cream.
Applications: Soft serve ice cream and desserts can be served straight up in a cone or bowl, or as a base for desserts such as banana spilts, milkshakes and rootbeer floats.
Size: Machines are available in counter top and floor models. Even footprints of large machines are relatively compact, with a high volume twin barrel machines being about 26" wide and 36" deep.
Capacity: As with many other types of equipment, one significant point to consider when selecting a soft serve machine is capacity.
Machine capacity is measured in volume, either gallons per hour or servings per minute. Lower volume is generally 2-3 serving per minute, medium is 4-5 servings and high volume is 7 servings.
Features: Soft serve machines are self-contained unit that will store mix, then churn and freeze it into ice cream, and dispense it. Recovery time is therefore important. If you require a medium or high volume machine for production, the machine must be able to freeze additional product to replenish what is being dispensed. Two options: Gravity-fed machines require staff to manually load liquid ice cream mix into a hopper located on top of the machines, and gravity does the rest. Pressurized machines us pumps to supply the freezing cylinder.
Many models have touchpad LED displays to set the temperature and/or consistency of the final product. Once set, the machines automatically adjust for whichever mix is used.
Other controls include a low-mix light that indicates when it's time to replenish the mix hopper. Some models also have an audible signal to indicate when to add more mix. If the barrel isn't full, the mix can freeze solid, preventing the dasher bar from turning. A frozen cylinder can break the blades, bend the dasher bar, or burn out the compressor.
Several models have a safety mechanism to prevent compressor burnout. On some, the compressor automatically shuts down if you don't respond to the low-mix alarm within three minutes. The compressor will cycle every 10 minutes to keep the product cold until more mix is added. Other models shoot hot refrigerant gas from the condenser to the barrel to keep it from freezing solidly when the mix level is too low.
Energy Source: To ensure widespread compatibility with most foodservice situations, most smaller units run on single phase 115 volts and larger units 208-230 volts.
Temperature Range: A temperature-controlled machine allows the ice cream to dispense when it reaches a certain temperature, usually 18º F to 19º F. Many machines have a "night" or "sleep" switch that lets you conserve energy overnight, where permitted by local health codes. In this mode, the ice cream is allowed to thaw and be held at 38º F until you're ready to restart the machine.
Construction: The heart of all soft-serve machines is the barrel where the ice cream is produced. Each manufacturer uses its own design for both the freezing cylinder itself and the beater or dasher bar that mixes and pushes the ice cream to the dispensing head.
There are two types of dasher bar designs: low and high displacement. High-displacement beaters are typically designed for batch, hard-pack ice cream production. However, some manufacturers use them in soft-serve machines to improve the machine's efficiency.
Depending on the type of product you want to serve the dasher bar motor speed should be considered. If you plan to use a product with higher butterfat a higher rpm motor may churn the mix too much in the barrel.
Blades attached to the dasher bar scrape mix off the walls of the cylinder as it freezes. Most are made with some sort of plastic, however they do wear, and if worn blades leave frozen mix on the walls of the barrel, the machine will operate less and less efficiently. To keep blades sharp some manufacturers have "self-sharpening" blades. Others attach blades to the dasher with a calibrated spring. That puts constant pressure on the blade as it wears to press it tightly against the cylinder wall. Blades typically need replacing every six months or so depending on volume. To indicate when a blade is ready to be replace some have wear lines to show employees when to change them. Others are designed to prevent employees from installing them improperly when they're cleaned or changed.
The power of any machine should match the kind of production you need for your operation. Dasher bar motors, for example, range from ½ hp and higher. Compressor motors start at 1 HP on small machines, while most machines have 2 HP compressors to quickly pull product from 38º F down to 18º F, and dispense cone after cone. Many models now use Scroll compressors, which are more energy-efficient than traditional compressor motors.
While these powerful components are in operation the machine is going to throw off a lot of heat. Since most soft-serve machines are located behind the counter or out in serving areas, that heat can affect both employees and customers in addition to how hard the machine itself works. You have a few options on how to handle that heat. 1) Air-cooled units offer placement flexibility as they don't require a water hook-up, only an electrical outlet. Allow about 3" of clearance around the entire machine, and plan to provide air conditioning to dissipate the heat from the compressor, dasher motor and condenser. 2) Water-cooled machines are a good option if you buy a model that has a self-contained recirculating system so you're not paying for water to go down the drain. Alternatively, you can use the waste heat from the water that cools the soft-serve machine to heat water in the rest of your operation. 3) Soft serve machines with a remote condenser, usually roof-mounted, will dissipate some of the heat outside. However, you must have a relatively short run to the roof for the refrigerant lines.
Maintenance: Since dairy products are susceptible to coliform bacteria, which can rapidly multiply to dangerous levels, many health departments require daily break down, cleaning and sanitizing of soft-serve machines daily. Before purchasing a soft serve machines, check with your local inspector or health department to know the rules for your area.
Several methods have been developed to ease the cleaning process, including washout kits, which are essentially faucet hookups for the top of the machine that enable you turn on the water straight into the hopper. Most suppliers also offer parts trays that give employees molded spaces in which to store parts as they disassemble and clean them. This helps employees track parts to properly reassemble the machine.
Other models have an auto-cleaning mode that flushes and cleans the machine innards at the push of a button. Even these models require disassembly periodically to clean and sanitize parts that may not get a thorough cleaning. Auto-cleaning can save employees a lot of time, and employers labor cost, if it significantly reduces the number of times the machine has to be stripped for cleaning.
Certifications: Units must be NSF listed under standard No.7, and UL Safety and UL Sanitation listed.
Manufacturers: ACityDiscount offers a lower, medium and high volume soft serve ice cream machines from SaniServ.
Sizing Guide for SaniServ Soft Serve Machines
20 quart per side
Two 4oz servings per minute
Four 4oz servings per minute
Five 4oz servings per minute
Seven 4oz servings per minute
Seven 4oz servings per minute
Seven 4oz serving per minute, per side
Four 4oz servings per minute per side