Checking Out Drop-Ins
A nicely lit, hot or cold food well built into a high-end countertop delivers a sophisticated, attractive food presentation. Installed properly, these units keep your hot foods hot (140°F and above) and cold foods cold (41°F and below) as required by the U.S. Food and Drug Administration Food Code. While drop-ins may seem like fairly simple pieces of equipment, there’s more to their selection and installation than meets the eye.
Both hot and cold drop-ins comprise a counter unit into which food pans nest. The drop-ins, which top-mount into the countertop, come in a wide variety of sizes to accommodate multiple pans in full-, half-, third- and even sixth-pan sizes. The drop-ins come in a variety of lengths as well as depths, including shallow “slim” versions that shorten the reach to the food.
A few basics about configurations: Hot wells can be set to hold foods hot at different temperatures. You can choose a single control on a single drop-in unit (which holds multiple food pans at one temperature) or you can gang individually controlled wells together into one long unit, but set each to a different temperature. Cold wells, on the other hand, just hold items between 33°F-40°F. Another category, which we’ll address later in the article, features combination units that switch back and forth between hot and cold holding. What many employees forget, however, is that these are holding units. You have to load hot foods hot and cold food cold to begin with, or you’ll never achieve proper temperatures.
Manufacturers offer drop-ins that are drawn—meaning they’re formed into the shape of a drop-in well out of a single sheet of stainless—or welded, which means they’re made of pieces of stainless welded together into a drop-in well. By pure physics, drawn wells will stretch and thin the stainless, especially in the corners. Welded drop-ins generally are considered the more durable product. Consultants suggest you check that the stainless is at least 18-gauge; 20-gauge or thinner is harder to weld. Remember, the thicker the stainless, the lower the gauge number.
The higher the grade of stainless, the greater its ability to withstand corrosion. You don’t want anything less than 304 stainless and 316 is the most corrosion resistant, but you’ll only get 316 in drop-ins if you pay for special fabrication.
According to an article by Yardney Water Filtration Systems, Riverside, Calif., all grades of stainless are corrosion resistant, but not corrosion proof. The corrosion- resistance properties of stainless are impacted by myriad factors, including temperature fluctuations; the pH of the water coming into contact with the stainless; chemical properties of the water, such as chlorines, sulfates and salts; dissolved solids; the metal’s surface condition and numerous other elements (see sidebar, “Stainless Care”). A best practice for hot and cold wells is to wipe them dry with a soft cloth at the close of service each day to prevent standing water and its deposits from eroding the metal.
More than one story has circulated about hot drop-in units cracking fancy countertops in brand new serveries. When it happens, it’s not only heartbreaking, but it’s expensive to replace what are sometimes very high-end counter materials. Cracking, warping, discoloration and other countertop catastrophes are easy to avoid, according to Stan Schwartz, Principal of Professional Foodservice Design Inc., Cleveland. “We always install a stainless countertop insert, integrated with the non-stainless countertops such as granite, stone or composition materials,” he explains. “It creates a thermal break between the hot drop-in and the counter material.”
In specification sheets, you might read that a hot dropin can run wet or dry, but the majority of specialists we spoke to recommend running units wet only. Hot units are heated from below by elements. They heat water in the bottom of the insert, which turns to steam and envelopes the food pans. “Most drop-ins that have the element actually require that you use water. The heating is too inefficient without it, and you run the risk of getting hot spots in the bottom, which can stress the metal,” says Trish Jass, Senior Equipment Specialist at Robert Rippe & Associates, Minneapolis.
With water in the equation, it’s smart to specify units with drains as well as floor drains. You can opt for drop-ins that come plumbed to fill the well automatically or install a fill faucet nearby. Otherwise, you’ll have to use a bucket to fill and empty the wells every day. Units should be insulated, no matter what wattage you choose: low, standard or high. “If we hear from a client that their food just isn’t hot enough, we may switch to using a higher wattage unit on the next project…and vice versa,” Jass says. You also need to watch the electrical configurations, which typically range from 120V single-phase to 240V 3-phase.
Truly waterless hot drop-in alternatives are a unit from one maker that wraps the hot wells in flexible elements, encasing them in a blanket of heat; a unit from another manufacturer that delivers heat through a triple dry-channel configuration; and an induction unit from another maker. Waterless units have the advantage of taking water out of the drop-in equation altogether. They’re worth consideration as they eliminate the need to supply water, maintain water levels and drain it after, and there’s no need to delime equipment.
Control choices are temperature presets or infinite temperatures within a range. Most operators prefer the infinite settings to ensure they can get all of their selections hot enough for their quality standards. Presets can run the risk of being too high or low for the foods held.
According to Schwartz, the current cold-pan market is moving away from cold pans requiring ice— and the labor to fill, empty or drain them each day—to two main, mechanically cooled technologies: air-over and cold-wall cooling. Air-over is actually air over, under and between food-pan inserts; these units generate and distribute cold air around the undersides of the food pans and sometimes over the tops of the foods. By NSF/ANSI 7, “Commercial Refrigerators and Storage Freezers,” standards, foods without cold air flowing over the top have to be recessed about 3 inches below the top edge of the drop-in to maintain their required temperatures. With cold air flowing over the top, foods can sit up higher in the pans, which makes the display more attractive and perhaps a little more accessible to customers.
How the air distributes over the top of foods is a point of differentiation among the manufacturers. Ask how and why their particular airflow keeps foods at temperature without drying out the top layer. Frequent batch changes will help you keep ahead of the effects of drying, too.
Cold-wall-style cooling means the components delivering refrigeration wrap around the drop-in well, either through copper tubing or by submerging wells in a eutectic liquid. Either way, cold conducts through direct contact with the insert walls. Some cold-wall-style units allow you to load foods higher in the pans than 3 inches from the top edge and still meet NSF/ANSI 7 requirements. Ask how high pans should be filled when you’re in the specifying process.
With cold drop-in units, make sure the architects and installers understand that the refrigeration system under the counter needs to be able to disperse its heat. The counter base needs to include louvers or some other means of ventilation. You even may want to install fans below the counter to dissipate heat.
Be sure to install a floor drain below cold units to take care of condensate. Keep the condenser both accessible and clean; if it gets gummed with dust and debris, it insulates the coil to the point where it can’t expel its heat. The refrigeration system will work harder and harder until it fails.
A great approach, if budget permits, is to remote the refrigeration altogether. It’s more expensive, but it takes the heat and noise out of the servery. Plus, remote refrigeration is easy to service and maintain.
Hot/cold combination units are growing in popularity. Their biggest advantage is flexibility and saving real estate. If you can reduce the amount of counter space you need to serve your menus throughout the day, you save money.
Hot/cold units operate in a few different ways, depending on the manufacturer. You can choose a unit that switches from all hot to all cold. Other styles mix hot-only and cold-only wells within one ganged unit. Finally, there are models in which each individual well in the ganged unit can switch from hot to cold as needed.
Combination models accommodate every menu mix you can think of in a small footprint—warm oatmeal with cold fruit; hot baked potatoes with cool sour cream, bacon and chives; hot taco meat and shells with chilled cheese, lettuce and tomato—all side by side. All of the units that switch between hot and cold will take time to reach their respective temperatures— maybe even an hour—and some hot/cold units come with special instructions and switches that need to be activated to convert from hot to cold and back. It’s likely we’ll see more of these combination units on the market.
When it comes to making your hot and cold drop-in units last, stick to mild detergents or manufacturer-recommended cleaners and soft cloths. Stainless is tough, but chemicals such as chlorine will result in pinhole leaks, scrub pads will scratch the surface and hard water will eat through it after a time if you don’t maintain the metal. Dry your units thoroughly to remove standing water.
Hot & Cold Drop-In Unit Makers
*APW Wyott Foodservice Equipment/ Standex
*Atlas Metal Industries Inc.
*Duke Mfg. Co.
*Low Temp Industries
Marsal & Sons
*Mfg. also makes units that switch from hot to cold.
CookTek Induction Systems LLC/ Middleby
FMP/Franklin Machine Products
LaRosa Refrigeration & Equipment
* Mfg. also makes units that switch between hot and cold holding.