Foodservice Equipment Reports

FER FOCUS: Freeze Frame

With winter long gone, it’s OK to bring the words “slush” and “ice” back into the vernacular. As the weather warms up, your customers will be looking for icy-cold drinks from granitas to carbonated slushies to frozen margaritas and daiquiris.

Just as customers have a tremendous variety of beverages from which to choose, you have a number of options when it comes to frozen-beverage machines. Your customers have the ultimate say over which type is right for your operation, but factors involved in selecting equipment include the types of beverages you plan to serve, the volume of drinks you anticipate serving and how quickly you have to serve them.

Basic types of frozen beverages include granitas (from the Italian for “grain”), which have a grainy mouth feel because of their larger bits of ice; frozen uncarbonated beverages (FUBs), often called slushies or smoothies, which have a finer, smoother texture; and frozen carbonated beverages (FCBs), which have a lighter, fluffier texture from the CO2 incorporated into the beverage.

While the machines that make each type of beverage are similar, they all have some distinct characteristics. And although some FUB and granita machines also make products with dairy, such as shakes, espresso drinks, frappes and some smoothies, for purposes of this article we’ll stick to non-dairy beverages. FUB machines, often called barrel freezers, also can make frozen alcoholic beverages.

As a side note, two other types of machines make frozen beverages, but they tend to work best in specific niche markets. One is a shaver/blender, designed for making individual or small-batch drinks; it’s often used in service bars for frozen cocktails. The other is a high-volume machine that blends and mixes drinks in individual cups but at high rates of speed for service in venues such as stadiums.

Turn Up The Volume

Volume will be a key factor in the type of machine you pick for a frozen-beverage program. Consider not only how many drinks per day you’ll serve in a particular-size glass or cup but also how many the machine will need to produce during a rush. Sports venues, for example, need to serve huge quantities in a relatively short time frame. Same thing goes for college/university or B&I cafeterias.

C-stores, on the other hand, may serve a high volume of drinks, but they’ll likely be spread out over the course of a day. Busy bars in warmer months also may serve a large number of frozen cocktails, but, again, demand will be fairly consistent over the course of a night. Restaurants may serve medium volume in terms of numbers but likely will sell more during meal periods, so units must have the pull-down capability to keep up with demand.

Most granita and FUB models are batch-type machines. You fill the bowl or product hopper with mix, and when the mix is frozen, operators can dispense drinks until the bowl or hopper needs refilling. Many models, however, now have built-in auto-fill systems or offer them as an option. Auto-fill systems usually are configured in one of three ways: They feature a refrigerated container of product, an incoming line filled with powdered mix and water or an incoming line filled with bag-in-box syrup and water.

Granita machines, with their clear polycarbonate bowls, are great merchandisers but are the smallest of the three machine types. The bowls typically hold 1 1/2-3 gallons of product. The machines freeze/refrigerate from the bottom, which is one reason their drinks are grainier and why they don’t have the same pull-down capacity of larger barrel freezers.

However, many of these machines come with an auto-fill feature, so product is constantly replenished as drinks are dispensed. If your volume isn’t very high, these machines will be able to keep pace, but if you serve several drinks in a row, it may take a while before the incoming mix freezes adequately.

Medium-volume FUB machines take you a step up in both capacity and product quality. These models are barrel freezers that range in capacity from about 5-12 gallons. The machines are designed for the product barrel to act as the evaporator. The mix freezes inside the barrel cylinder and constantly is scraped off of the walls.

Typically, these machines have a product hopper above the freezing barrel that holds refrigerated product in reserve. As the frozen product in the barrel is depleted, more refrigerated product is added. When the hopper is empty, however, you have to refill it manually unless the machine has an auto-fill feature. Like those on smaller granita machines, auto-fill systems for barrel-freezer models can take a few forms, depending on the type of product you serve.

FCB machines, which are similar to FUB models but designed to accommodate lines for water, CO2 and syrup from bag-in-box containers, generally have the highest capacity because they’re continuously replenished. Some of them can freeze and dispense as much as 35 gallons of product per hour. FCB units also typically give the most bang for your buck because CO2 adds volume to the product, meaning you need less syrup and water to fill a cup.

The Big Chill

No surprise, the larger the machine, the larger its refrigeration system. As with most refrigerated equipment, manufacturers do their best to size the compressor and condenser to the evaporator and the intended capacity of each model. When you spec models, check out nuances among the different makes that might affect performance as well as energy and water consumption in your stores.

First, the type of product you’re serving will determine the load on your machine’s refrigeration. Brix, or sugar content, acts as an antifreeze, which helps give slushies and smoothies their texture. Ideal brix range is 10-15%. Most drink mixes will freeze at about 28˚F. However, add alcohol—another antifreeze—and your machine will have to lower product temperature to about 19˚F or 20˚F before it will freeze.

Anywhere the ambient temperatures are hot—think the tropics or just about anyplace south of the Mason-Dixon line in the summer or close quarters in a kitchen—a piece of refrigeration equipment like a frozen-beverage machine will have to work harder to do its job. Manufacturers use a few different tricks to help their machines take the heat.

A couple of them make models with oversized condensers so they can more quickly lower temperature and decrease recovery time. One markets its model specifically to operators in hot climates.

In general, machines are air-cooled. But in many applications, air-cooled units wouldn’t get adequate circulation and would end up working too hard, possibly burning out the compressor. Air-cooled units typically need 6 inches of clearance on all sides for maximum efficiency.

If you plan to set several machines side by side on a countertop or recess-mounted in a wall, two other options will suit you better. Water-cooled machines work well in tight spaces where air can’t circulate, but that means you have to pipe in cold water. Closed-loop systems, usually tied in to the HVAC, are more economical because water used for cooling doesn’t go down the drain. The other option is to place the condenser in a remote location—on the rooftop, usually, but a storeroom with good circulation works if the roof isn’t accessible.

Other features that can make machines more efficient include standby or night mode as well as energy-saving components. Night mode lets you program a time or manually flip a switch when the machine won’t be in use. The machine allows the product to thaw but keeps it refrigerated at about 38˚F, so when the unit switches back to normal operation the product refreezes more quickly.

One manufacturer uses space-saving and more energy-efficient scroll compressors in its units as well as a design that sheaths the barrel in refrigerant rather than simply wrapping copper refrigerant tubing around the barrel. Greater exposure to the refrigerant means faster freeze and recovery times and less compressor cycling.

The Right Stuff

As mentioned previously, the primary feature of granite machines is their clear, polycarbonate bowls that help merchandise the product. Because demand on their smaller capacity is less, they tend to incorporate more plastic parts than larger, heavier-duty machines.

All frozen-drink machines have a beater or dasher with attached blades that resembles an auger. As the drive motor turns the beater, the blades scrape frozen product off of the evaporator, mix it with the rest of the product in the bowl or barrel and move it forward to the dispensing valve.

Beaters/dashers in granita machines are molded plastic and perform just fine if you follow the manufacturers’ recommended cleaning and maintenance procedures. FUB and FCB machines typically are constructed of stainless with a clear polycarbonate window just behind the dispensing valve that lets customers see the product. Beaters and blades in these machines also are constructed of stainless, as is the barrel-shaped evaporator they fit inside. In many models, the beater and drive shaft are two separate pieces and can be taken apart for cleaning, but at least one maker uses a one-piece stainless dasher, meaning there are fewer parts for employees to reassemble properly after cleaning.

Blades wear over time and should be checked occasionally and replaced when necessary. More importantly, a couple of factors can cause damage to the drive motor that rotates the beater/dasher. First, product that freezes too much can put strain on the beater/dasher, burning out the drive motor. Most models now have a torque sensor in addition to a temperature sensor to gauge the product’s thickness. If the product becomes too viscous, the compressor will shut off.

Sugar also can ruin a drive motor, and because virtually all of the drinks you’ll dispense from one of these machines contain sugar, it pays to follow the manufacturers’ recommendations concerning cleaning and maintenance. Most models have a seal around the beater drive shaft between the barrel or bowl and the drive motor. The seal or gasket keeps product from seeping into the motor where the sugar content can gum up the works.

These gaskets need replacement on a regular basis; depending on the volume your machine produces that could be anywhere from quarterly to yearly. Also, some products will have a more adverse effect on seals than others. Coconut oil, for example, deteriorates seals more quickly. If you plan on serving drinks such as pina coladas, one maker offers its machines with a special seal design to work with coconut-content drinks.

Other features to look for in all types of frozen-beverage machines include electronic controls that provide self-diagnostics and programmability for standby or night mode and auto-defrost cycles; mix-level indicators that alert employees when product needs to be replenished and a “mix out” safety switch that shuts off the compressor when the mix is too low; self-closing valves that prevent product from accumulating and melting; and environmentally friendly foamed-in-place insulation. Take a close look at the number of parts your employees will be expected to handle during cleaning and maintenance and really vet how easy these units are to disassemble, clean and reassemble.

Some other features you may want to consider include wireless monitoring that you can access from a computer, laptop, tablet or smart phone; an auto-mix system that automatically adjusts the ratio of powder or syrup to water to maintain the proper brix; and an auto-fill system if one isn’t built into the machine.


Keep It Working

Like the human body, a frozen-beverage machine can turn against itself. The very product this equipment is designed to produce can destroy it. Many a service agent can tell you horror stories of what happens when these units are mistreated.

Sugar is a frozen-drink machine’s greatest enemy, so it’s important to clean your equipment regularly according to the manufacturer’s recommendations. Usually, this means defrosting and draining the machine, disassembling the primary working parts—bowl or barrel, beater and drive shaft, dispensing valve, drip tray, etc.—and washing all of the parts in warm water and mild detergent. Rinse and reassemble the machine. You should sanitize the machine and lubricate moving parts with a food-grade lubricant at least once a month.

Machines should be wiped down every day, but—depending on local health codes and the products you’re serving—they only need to be cleaned every week or so.

Maintenance is simple but extremely important with these machines. If your units are self-contained air-cooled models, usually they’ll have a removable air filter that should be cleaned at least weekly and more often if the machines are in a dusty or dirty environment. Seals, gaskets and/or O-rings should be checked quarterly and replaced as necessary or according to the manufacturer’s recommendations. If they’re not, the drive shaft will scrape away at parts it shouldn’t. Make sure your counter is equipped with a tube of petro gel and liquid or powder sanitizer.

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