Foodservice Equipment Reports

Post-Mix Paradigm

We’re probably dating ourselves here, but some of us still remember getting cold sodas from the soda fountain in the corner drugstore (when a bottle of Green River or Grape Fanta just wouldn’t do). A good soda jerk could pull a cherry-vanilla cola or lemon-lime soda with just the right amount of flavor and fizz every time. Nowadays, post-mix beverage dispensers produce almost everything old-time soda jerks used to serve up, except maybe the small-town homilies.

Customers generally love the versatility of these new dispensers, and likely you will, too. But before you run out and snag one (or a few hundred) there are a few things you should keep in mind.

First, if a beverage distributor provides the dispensers you have now under contract, you may not have much of a choice in the models available to you. Typically, if you have an agreement with one of the big beverage companies, they supply the product and the equipment. You may be perfectly happy with that sort of arrangement, as it usually leaves the hassles of maintaining the equipment to the distributor.

Owning your own equipment, however, has its advantages, too. With your own dispensers, you’re free to choose whatever beverage products you want, even from competing beverage companies, giving your customers the flavors/brands they demand. You also get to select the equipment that best suits your needs.

Size Up Demand

Figuring out what size dispenser you require involves a number of factors of course, including physical space limitations, customer traffic, the number of brands or flavors you offer, and type of beverage service.

How many brands or flavors do you want to serve your customers? With conventional systems, the more flavors you offer, the more dispensing valves you need. Units with six to 12 valves are common, but some models have as many as 16 valves, and one manufacturer offers a double-sided unit designed for a service island with 20 valves, 10 per side.

Dispensers have grown more sophisticated over the years, however, and now can dispense multiple flavors from a single valve. A 4-valve unit, for example, can dispense four brands per valve as well as three bonus flavors per valve, giving customers more than 60 flavor combinations to choose from.

How do manufacturers prevent flavor transfer from one drink to the next? Clever design, basically. One maker’s dispenser, for example, blends the syrup with soda water about an inch below the nozzle in mid-air to prevent flavor overlap. Another solves the issue by having the soda- or plain-water stream run a bit longer than the syrup, to rinse any remaining flavor residue out of the nozzle.

The number of valves you spec may not simply reflect the brands you want to offer, but how many customers you need to serve. According to one manufacturer, studies have shown that a single dispense point can serve 12-oz. drinks to about eight people per minute. If you serve more than 480 customers per hour during peak hours, you may need more than one dispenser.

The number of valves, and the possibility you may need more than one dispenser, brings us to physical space limitations. Most of you have them, which is why dispenser makers have tried to pack more oomph into the same footprint in recent years. By building units that dispense multiple brands/flavors per valve, manufacturers can offer you more flexibility within your limited space.

A typical 8-valve unit takes up about 30” of countertop space. And, of course, now there are 30” models with four valves that can dispense 16 brands. Larger units generally run about 44” wide, but some are as wide as 60”. Remember, too, that the more brands you offer, the more storage room you’ll need behind the scenes for syrups and CO2 tanks. More on that later.

Keeping Your Cool

Space limitations also usually dictate your choice of a mechanically cooled dispenser or one that uses an ice-chilled cold plate. Mechanically cooled dispensers (also known as CEDs, or countertop electric dispensers) refrigerate incoming water with a compressor system. CEDs are used where there’s limited headroom, or in operations with a separate ice dispenser.

Less expensive ice-cooled dispensers take up more volume by adding an ice bin on top of the dispenser that usually holds anywhere from 50 lbs. to 300 lbs. of ice. The ice freezes a cold plate, which in turn chills a water bath. Incoming water runs through tubing immersed in the chilled water bath, producing a cold drink at the valve or dispensing head. These ice-cooled designs also have the advantage of being able to dispense ice along with beverages.

Dispenser makers play with both the capacity of the ice bank and the water flow rate to come up with a dispensing rate. Valves can typically dispense 2 oz. to 4 oz. per second. But to match a machine with your volume requirements, look at how many drinks a machine can dispense per minute without exceeding 40ºF.

One machine, for example, might be able to dispense 100 12-oz. drinks at a rate of two per minute before finished drinks exceed 40ºF. Adjust the water flow to allow the machine to dispense four 12-oz. drinks per minute, though, and capacity may only be 40 drinks before they come out warmer than 40ºF.

Space, or lack thereof, isn’t your only consideration when deciding whether to spec a CED or ice-cooled dispenser. Type of service also plays a role. The dispenser you spec for your drive-through window, for example, likely will be very different from the self-serve unit you choose to put out in the dining area.

For drive-through or counter service, you’ll probably want a model with an auto-fill feature that dispenses a set amount of beverage depending on which button a server selects. Auto-fill lets employees complete other tasks while the unit dispenses drinks.

Ice Is Nice

Most customers like at least some ice in their drinks, and on average, customers fill cups one-third full of ice and two-thirds full of liquid. You may remember from your physics class that ice takes up twice the volume of liquid, so a 16-oz. cup that’s one-third full of ice will still hold a little less than 11 oz. of liquid.

That also means you’ll use about a pound if ice for every three drinks served. Factor in your customer counts and you’ll have a good idea of how much ice storage you want. Don’t forget, though, that ice-cooled beverage dispensers require even more ice to chill cold plates and water baths. In general, for every pound of ice used in drinks, a dispenser will “burn off” another pound on the cold plate.

There are several ways to supply that ice. Some beverage dispensers have an ice bin on top of the unit that you have to fill manually. That may be OK if the dispenser is behind the counter, your employees are properly trained to refill it, and you use a sanitary means of transferring ice from ice machine to the dispenser. One type of dispenser specifically designed for this is a “drop-in” dispenser, a unit with a dispensing head on top of an open ice bin that you can set in place.

If your dispensers are self-serve, or you have a high-volume operation in which employees are too busy to refill the dispenser’s ice bin, an auto-fill machine is the way to go. You can choose between two types. Most common are units that have icemakers on top instead of just ice bins. The drawback, especially if the dispenser is intended for self-serve use, is that it puts the noise and heat of a compressor in your dining or serving area.

The way around this is a satellite or remote ice making system. Manufacturers of cube-ice and nugget-ice machines handle this in different ways. Some cube icemakers are designed so the compressor can be mounted on the roof. Customers are still subjected to some noise from cubes falling into the ice bin as they’re released from the evaporator plate, but the systems put the heat and noise from the compressor outside.

Nugget ice, because it’s essentially shaved ice that’s compressed into small chunks, can be pumped through plastic tubing. This allows you to situate chewable-ice machines either under the counter and out of sight, or, to reduce noise and heat even more, in a back storage room. One manufacturer makes ice machines that can be located as far as 75’ away from an ice and beverage dispenser. And a special diverter valve allows you to automatically fill two dispense points from the same ice machine.

Some customers prefer nugget or chewable ice over cube ice, and nugget ice is more popular in some areas of the country, (typically warmer, more southern climes). Obviously, higher ambient outside temperatures will have an effect on ice production, so size your icemaker accordingly. Also recognize that nugget ice doesn’t store as well in ice bins as cube ice. It clumps and freezes together, making it harder to dispense. Again, take care when sizing your ice machine if you plan to serve nugget ice.

To give customers the option to choose which type of ice they want in their drinks, at least one manufacturer offers an ice and beverage dispenser that produces cube ice, but has an ice crusher, so customers can dispense crushed or cube ice into their drinks.

Fizzy Flavors Galore

As we mentioned at the top of this story, what the latest ice and beverage dispensers offer is versatility and flexibility. Multiple-brand valves have been around for a while, and all dispenser manufacturers now offer optional flavor shots.

These additional flavors aren’t dispensed at the same time as the drink itself, but separately. Bonus flavors come in half-size bag-in-box packaging and can be stored alongside brand syrups in the storage room. You hook them up directly to the so-called “dosing” valves in the dispenser at ambient temps instead of running lines through the cold plate or ice bank. By letting customers mix and match these added flavors, beverage dispensers (whether self-serve or counter service) can come pretty close to providing the same flavors, if not the same experience, as old-fashioned soda fountains.

Of course, carbonation is what gives soda its fizz. In a conventional setup, a carbonator blends CO2 gas with water in the back room near the syrup containers, pumps and tanks, typically at room temperature. The thing is, water absorbs more CO2 at colder temps, becoming totally saturated at about 36°F, which means that water carbonated at ambient temperatures is a lot less fizzy than it could be.

One manufacturer addresses this by building a carbonator straight into the dispenser’s cold plate. The company says benefits of this built-in arrangement include fizzier water, lower installation costs and fewer service calls. Other companies situate the carbonator within the ice bin, but not inside the cold plate. In both cases, the process is called “cold carbonation,” an option to look for when setting purchase specs. Water also absorbs CO2 better at higher pressures, which means you may need a booster pump to raise water pressure.

Not all beverages on your menu are carbonated, however. Another cool feature on dispenser models from most manufacturers now is the ability to switch some valves from carbonated to noncarbonated beverages. That way, you can serve beverages such as iced tea or lemonade, and even some juices, from the same dispenser that serves your sodas, giving customers even more choices. Arnold Palmer, anyone? Or a raspberry-vanilla Arnold Palmer, perhaps?

On some dispensers, the change involves a quick service call to change a manifold. On one manufacturer’s models, you can easily make the switch simply by flipping a lever, making beverage menu changes or weekly specials easy to accommodate.

Odds And Ends

Post-mix dispensers have water inlets (typically 3/8”) for direct hookup to a water source. In the case of models with carbonated/noncarbonated beverage options, the units are pre-plumbed to both a water line and carbonated water line. Water quality is important, and poor quality water with high sodium, calcium or sulfur content, for example, can affect both taste and carbonation. If your water isn’t filtered, most makers offer filter cartridges as an option.

Best operating pressure is around 50 psi, and you want it to be steady. If your water pressure fluctuates, it will affect the mixing ratio, which obviously affects taste of the finished drink. Most carbonated beverages mix in water-to-syrup ratios ranging from about 4.5:1 to 5.5:1. Inadequate water pressure will change the brix, again affecting both taste and carbonation.

Your 3- or 5-gal. bag-in-box syrups or concentrates can be stored in a remote location and pumped to the dispenser where they’re mixed with water and CO2. Rack systems are available for both syrups and CO2 tanks, and depending on your storage area, often they can be expanded either vertically or horizontally to help you squeeze the most flavors and equipment into the smallest space.

Along with temps, pressures and ratios, cleaning is important, too. Drain lines on post-mix machines should be rinsed with hot water at least once a day or once a shift, depending on volume, to help prevent algae growth. To keep valves and beverage lines clear and working properly, you should run manufacturer-recommended cleaning and sanitizing solutions through them weekly. Remove the nozzles and diffusers from the dispenser valves on the same schedule and soak them in cleaning solution for 10 mins., then rinse and sanitize them before reassembling the dispenser.

Most manufacturers recommend cleaning and sanitizing the icemaker and/or ice bin at least once every three months. And it’s a good idea to ask for at least two service calls each year to calibrate the dispenser to be sure carbonation and brix are set at proper levels, and valves are dispensing at the correct flow rate.

Other options to consider include sanitary lever valves versus push button valves, a key-lock switch for valves to prevent product theft, custom graphics on lighted merchandising panels and more.

Take a close look at your application and figure out what your customers want, and you’ll find a carbonated beverage dispenser that fits your volume, space and service needs.

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