Any cabinet of this type will keep food warm until it's ready to be served. The most basic holding models will simply maintain a steady temperature, usually up to 190 degrees F. However, not all cabinets will work as proofers, which provide the added benefits of humidity and air velocity control. That enables these units to make fresh dough rise at the right speed and keep moist foods warm longer without drying out.
Proofers and combination models will have a reservoir to hold water to produce humidity and most include individual controls for temperature and humidity. These levels will need to be monitored to ensure that food maintains quality and dough is kept in a moist-enough environment to promote the activity of the yeast.
Some cabinets also offer rethermalizing capability, which can bring pre-cooked and chilled foods back up to serving temperature. Cabinets are made up of modules that allow for heating, holding, and proofing. These modules are removable for easy cleaning and simple upgrading. When upgrading or going from a heated cabinet to a proofing one, you don't need to replace the cabinet, just the module.
Access and Slide Types
Cabinets come in roll-in and roll-thru types, which accept full pan racks or specialty racks to make it easier to hold foods warm in large quantities. Reach-in and pass-thru types are available with various slide options. Many have fixed slides designed to hold standard-sized sheet and steam pans. Some are available with adjustable, universal wire slides for holding a variety of sizes and styles of pans. Some may have extra depth, allowing for 16-inch pizza pans.
Heated cabinets come in four sizes—full, three-quarter, half, and undercounter. The size you'll need will depend on what you're using the unit for. If you're simply moving a few pans of food around in the kitchen, a smaller unit may work. If you're preparing several complete, plated meals to be delivered, or preparing dishes for a buffet or catered event, you'll likely need a full-sized unit. It's important to know that half-size units will not fit under most counters, so look for an undercounter model if you need that capability.
Another consideration is whether you want the unit to be mobile or stationary. Mobile units have large, sturdy casters that enable them to move not just around your kitchen, but to off-site serving locations. All you need is a proper electrical outlet and you can serve hot food from one side of town to the other. Be aware that units with NEMA 5-20 connectors require a 20-Amp plug, which may not be available in all facilities. To ensure you can plug it in everywhere you go, choose one with a NEMA 5-15 plug.
It is also important to consider what type of casters you will need on your cabinet. If the mobility of the unit is necessary only for cleaning or moving short distances, regular casters should be sufficient. However, if the cabinet needs to move across uneven floors, will be taken outside, or will have to travel longer distances, heavy duty wheels may be needed. Wheels and casters with swivel and braking capability are recommended for these applications.
Most heated holding cabinets are available in aluminum or stainless steel. They may be insulated or non-insulated. While non-insulated varieties may be less expensive initially, they may cost more in the long run due to increased energy costs. Many are also covered with polymer armor panels, which may add to energy conservation, but, more importantly, protect your box from dings and dents when you move it. These panels have molded hand holds and can prevent against damage to walls and doors. They also provide a cool-to-the touch exterior for easy moving and provide options for colored exteriors.
Doors may be full- or half-size. Full-size doors often provide greater accessibility and convenience, since you can open the entire unit at once. Half-size doors reduce energy costs by allowing you to open only a portion of the unit, reducing the amount of heat that escapes when the door is opened. It may be beneficial to consider whether door hinges are field-convertible as well, as these will allow you to easily switch between a right-hand and left-hand opening door.
Doors are available in a few types, depending on your needs. They may be solid or have inserts made of glass or polycarbonate, which allow the operator to see inside the unit without disturbing the heating or proofing cycle. That means you can check on the condition of your foods, find ones you want to remove, or locate empty slides without opening the door.
Solid doors provide more durability and insulation to keep heat where it belongs.
Of the transparent inserts, glass is the clearest and the longest-lasting, but comes at a higher cost and, of course, can be broken if abused.
Polycarbonate doors are break-resistant and shatterproof. Polycarbonate also has a lighter weight than glass and typically is less expensive, but it is also susceptible to scratching and clouding over time.
Digital controls are available, which can make for reliable temperature and time adjustment. Many models with them also have programmable cycles for specific types of food, reducing the likelihood of operator error. Manual controls might be preferred by some due to their simplicity and lower cost. Either type can be placed at the top or bottom of the unit. This can help prevent accidental manipulation of the controls and damage that can occur in transit. Typically, if you're going to be proofing or otherwise creating a humidified environment in your cabinet frequently, you'll want to opt for controls on the bottom of the unit.