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April 2010
SPECIAL REPORT

Double Duty, Double Time

Two-sided cooking speeds service and doubles your capacity in the same space. Is it right for you?

By Mike Sherer

If someone bets that you can't double your capacity and speed service on your griddled and grilled items in the same footprint you have now, double down. By cooking both sides at the same time, two-sided equipment can cut cooking times of a wide range of menu items in half.

While most of you are familiar with clamshell griddles that make quick work of frozen burger patties, or the increasingly popular sandwich press (that usually goes by the fancier name of panini grill), you might not know that both types of equipment can cook a variety of foods, from bacon and burgers to poultry, tortillas and tilapia.

Like other pieces of foodservice equipment that seem to do it all (think combi ovens, or microwave ovens when they first came out), two-sided griddles/grills aren't right for everything. That's a good thing; imagine if the only way you could order your morning eggs was fried. But anything you already throw on a griddle, and most of what you put on a grill/broiler, you can cook on clamshell equipment and usually much faster.

Key factors predicating your decision to purchase two-sided cooking equipment are menu and speed of service. If you already use a griddle or grill for a lot of your menu items, then you might want to consider two-sided cooking to add capacity. If your grill or griddle is slowing down the entire kitchen during your busiest times, then two-sided cooking can free up the bottleneck and improve customer service.

With a sandwich press you can upgrade your sandwich menu with panini sandwiches, add new grilled sandwiches, and quickly heat/grill items like quesadillas. Many models also cook some of the same items that work well on larger clamshell griddles, which could increase speed of service and/or help you handle more volume.

You have lots of options when it comes to taking the plunge into two-sided cooking. If volume justifies it and you need to solve kitchen bottleneck issues noted above, you can jump right into large, automated two-sided grills. If you want to test some new panini-type sandwiches or experiment with two-sided cooking on some menu items (grilled fish, chicken, vegetables, etc.), you can start with a sandwich press or panini grill and add another later.

A third option is to add a platen (which is what the top half of the clamshell is called) to your existing griddle. A few manufacturers offer this option on their equipment, letting you add two-sided cooking capability to your griddle in about 1' increments.

Contact Sport
Two-sided cooking equipment uses direct contact to transfer heat and cook product. The top platens come in contact with the food on the griddle/grill below. Keeping the platen level so you get even distribution of heat on the top of the products you're cooking is important. The big difference between high-production, two-sided cooking equipment and lighter duty grills and sandwich presses has a lot to do with how big this gap is and how you set it.

Lighter duty two-sided grills and sandwich presses often allow a gap between cooking surfaces of as much as 4½". The top platen (or platens on a split-top grill) is typically gimbaled in some way to keep it level when lowered onto products. And most platens are counterbalanced, usually with springs, to make it easy to raise and lower the platen manually, as well as maintain even pressure on the product of about 3 lbs. or 4 lbs.

Obviously, the idea is to give you a great deal of flexibility over what you put on your grill, from thick sandwiches to very thin tortillas.

High-production grills generally allow you to set the gap between upper and lower surfaces only from zero to about 1½". These units are designed for high-speed cooking, not for heating or grilling sandwiches (though they'll generally handle a standard grilled cheese sandwich). The gap settings on most of these models can accommodate burgers, chicken breast filets, boneless steaks, fish, bacon, hash browns, pancakes and more.

When you adjust the gap setting on these units, you raise or lower the whole platen where it's hinged to the griddle/grill, keeping it level. Manufacturers have different systems for setting the gap and leveling the platen. One, for example, uses a three-point frame of reference; sensors feed this information to a microprocessor, so each time the platen is raised or lowered it can duplicate the same gap. Another uses a patented "micro-leveler."

A couple of manufacturers make automated two-sided grills. Their models automatically adjust the gap according to your settings. They also automatically lower and raise the platen at the beginning and end of each cooking cycle. One of these manufacturers uses air hydraulics to raise and lower the platen(s). The other uses a linear actuator (sort of like the rack and pinion steering on your car).

The idea is to take the guesswork out of the cooking process. With tight specs, for example, frozen burger patties will have a consistent thickness and weight. Set the gap for the thickness of the patty, set the time and temperature to cook the product from 0°F to 155°F, and the unit will take care of the rest.

On most models, menu items can be programmed, so all an employee has to do is load product onto the grill/griddle and push a program button. The unit automatically lowers the platen, then raises it when the product is cooked. Another advantage is that food safety is enhanced since products are cooked exactly the same every time (if your product specs are tight).

A couple of other manufacturers offer top platens as an add-on option to their existing griddles (at least one is available now, and another is being introduced at the NRA Show next month). These are manually operated but are available with automated lift.

Power On
You can spec clamshell griddles as electric or gas/electric combos. Top platens are always powered electrically whether the griddle itself is gas or electric. Since this type of equipment is intended to speed cooking, they're designed with quick recovery in mind.

Electric models range in power from about 4kW per 12" section of cooking surface (for a total of 8kW when you combine griddle and platen) to about 7kW (total 14kW) depending on the model. Input on gas griddles typically ranges from about 27,000 Btu to 33,000 Btu for each 12" section depending on the make and model; each section has an electric platen typically in the 4kW range.

In contrast, countertop panini grills generally range in power from about 1.7kW to 2kW total (top and bottom). Split-top units and light-duty clamshell griddles up to about 34" wide have roughly double the power with units ranging from 3.6kW to 6.5kW.

The Energy Star Connection
On the plus side, all this power doesn't have to come at an extra price, at least not for energy. Clamshells, along with griddles, joined the ranks of foodservice equipment categories that can qualify for the Energy Star program. Two-sided cooking equipment that qualifies generally uses 10% less energy than comparable traditional models.

Electric griddles that earn the Energy Star must have cooking efficiency of at least 70%; gas models must be at least 38% efficient. The specs also include maximum idle energy rates. For comparison, standard gas griddles on average are 32% efficient and use a 3,200 Btu/hr/ft2 normalized idle energy rate. Energy Star-qualified griddles have a normalized idle energy rate of 2,600 Btu/h/ft2.

Note that on electric models, manufacturers may configure heating elements differently. Most use tubular elements, though at least one uses flat elements. More significantly, on some models, heating elements may be attached to the back of the heating plate (usually steel ranging from 5/8" to 1" thick). Most, but not all, top platens are constructed with the heating elements sealed in die-cast aluminum.

What you should look for is consistently even heating across the cooking surfaces (both griddle and platen), whether gas or electric. There shouldn't be any hot or cold spots. Some manufacturers have test data on file that can tell you how their models perform.

Obviously, clamshells with gas griddles need both gas and electric hookups. You may need to update or change your electric service to accommodate either a gas/electric or all-electric clamshell. At the very least, you'll need a separate circuit, as these two-sided cookers use anywhere from 20 to 30 amps.

Most manufacturers make a couple of different versions of each model to accommodate more common 208V and 240V service, and there are even 220V models. Most also make a model to 380V or 400V for export (400V service is common in Europe), but you may be able to get such service here. Be careful in your selection. One maker's models, for example, are designed to be permanently wired in place, meaning you can't just unplug a unit and roll it to another spot under the hood if you want to change up your cooking line.

Again, contrast that with countertop sandwich presses that are typically wired for 120V service. Split-top grills and light-duty clamshells may be offered in 208V/240V versions. In most cases, you'll still need a dedicated circuit of around 20 amps.

Surface Talk
Another area where you'll find obvious difference between high-capacity clamshell griddles and lighter-duty grills is in materials used for the platen and cooking surfaces.

First off, you can get any model—clamshell or sandwich press—with a choice of smooth or grooved cooking surface. You also can mix and match surfaces on multiple-platen models—smooth surfaces on some sections and grooved on others, or even a smooth griddle and grooved platen to put grill marks on only one side.

Next up is the surface material itself. Let's start with big clamshells. Most griddle surfaces are polished steel plate. At least one maker has a special coating on its griddle surfaces to improve heat distribution, reduce heat transmission and make cleaning easier. Platens, however, may be either steel, coated steel or polished aluminum.

Whatever they're made of ends up being a moot point, as all makers use some type of nonstick "release sheet" that attaches to the platen. Most often Teflon (but in at least one case a proprietary polymer), these sheets are easy to remove and wash, and some are even reversible. Depending on use, they last from about 10 days to several weeks. Be aware, however, that they're on ongoing cost—about $10 to $12 apiece. But the upper platens would be nearly impossible to clean without them.

Panini grills and light-duty split-top clamshells are slightly different animals. Most manufacturers use fine-grain cast-iron cooking surfaces (smooth or grooved). At least one makes its units with polished aluminum cooking surfaces, one advantage being that the heating elements in the top platen are die-cast into an aluminum block, eliminating external wiring (it's in the handles).

At least one maker treats its cast-iron surfaces with enamel to make them easier to clean.

Staying In Control
Controls range from simple to sophisticated. Basic panini grills have an on-off switch, thermostat control and usually an indicator light to let you know it's heating. Slightly more sophisticated units have digital controls that include a timer.

Once you move from basic sandwich press to split-top light-duty clamshell grills, digital controls can include time and temperature settings that can be programmed for different products. An audible alarm signals when the product is done.

High-capacity clamshells have digital programmable controls that automate the cooking cycle. Set the program time, temperature and gap (product thickness); once an employee loads the griddle/grill, all he or she has to do is push a button and the controls automatically lower the platen, cook the product and raise the platen when finished. Models vary in the number of menu items you can set in memory from as few as three to as many as 75.

Temperature settings on thermostats range from 0°F to 570°F. A typical range is from 150°F to 425°F. The sandwich presses often have higher temperature settings of around 550°F or 570°F to brown bread more quickly or sear grill marks on products. You may have to play with your products in a manufacturer's test kitchen to find equipment with the right temperature range.

Safety features are common to most units. Most electric models, from panini grills to bigger clamshells, have temperature delimiting switches that prevent heating elements from getting too hot and burning themselves out. Automated models typically won't let employees start a cook cycle until the griddle/grill is at the proper temperature, which helps ensure food safety.

Most units have side-mounted grease troughs that are easy to empty and clean. Some models have grease troughs mounted in front—also easy to access and clean—but a couple have rear-mounted troughs.

And cleaning is about the only regular maintenance that's required. On gas/electric models, you should have the burners serviced according to manufacturer recommendations. And a regular tune-up (annual) is smart on automated units to make sure thermostat and gap settings are accurate.

For daily cleaning, also be sure to follow manufacturers' recommendations, particularly as to chemical cleaners. Cleaners are made specifically for certain surfaces; aluminum might react to one meant for stainless, for example.

Finally, don't forget that changing or adding a new cooking platform like two-sided cooking will change your operational procedures. That's certain to require some employee training, no matter how automated and easy equipment is to operate. And the increase in cook speed may mean an investment in extra warming equipment to hold cooked product until it's served.

Welcome to the world of fast.

Two That Break The Mold
There are two pieces of double-sided cooking equipment on the market that don't quite follow the rules of traditional clamshell griddles or panini grills. Depending on your menu or the operational problem you're trying to solve, either or both may be just the ticket.

The common denominator of most two-sided equipment is that it uses contact cooking. Food is heated/cooked by direct transfer of heat from the equipment itself, rather than through conduction (air in an oven), radiation (infrared heat from a broiler), or an intermediary (a pan on a stove).

A steam griddle uses a combination of contact cooking and steam heat to cook products, and like a traditional clamshell, does so in about half the time. The unit contains a steam generator that first heats a griddle plate, then circulates over the top of the product being cooked. The steam circulates only when the lid of the unit is closed.

Steam heating makes the temperature across the griddle surface perfectly uniform, and steam circulating over the top of the product is very efficient at transferring heat, so cooking is quick. The only disadvantage is that product can be browned on one side only, but a major advantage is moisture retention. It may not be ideal for burgers, but could be for fish.

The other product is a high-speed sandwich grill that combines contact heat, infrared radiation and microwave radiation to heat sandwiches and wraps to proper internal temps in about half the time of a traditional sandwich press, usually about 45 secs.

The unit has a quartz-glass bottom cooking surface. Foods are warmed from below with infrared heat. A top platen browns food (and can add grill marks to one side), and microwaves from the base of the unit speed cooking.

The unit is programmable for four overall cook-cycle times and four microwave time settings. Both upper platen and glass cook surface temperatures can be controlled individually, giving you a wide range of cook options depending on your menu
items.

The lid features an electromagnetic catch that locks closed until the cook cycle is complete. Both cooking surfaces are easy to clean. Heat activates a special cleaning solution for the quartz glass so all employees have to do is wipe it clean.

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