Rotisserie chicken ovens have been steadily gaining popularity in commercial kitchens since 1985, when Boston Market first introduced them to the restaurant industry. Today, more than 750 million rotisserie chickens are sold every year in grocery stores, club stores and food-service outlets.
While the slow-cooked birds are an easy meal for consumers and a smart choice for retailers, the grease they generate can present a challenge for commercial kitchen owners and for municipal water treatment systems. But how much grease do rotisserie chickens actually produce?
And what options do kitchen operators have to ensure they still comply with municipal pretreatment and plumbing codes?
A greasy situation
Unlike conventional ovens, which use racks to bake, broil, or roast meat, rotisserie ovens are created for one specific purpose – to roast meat on all sides and produce the taste and tenderness of slowly cooked meat. In commercial rotisserie ovens, chickens are typically skewered on horizontal rods and rotated to cook evenly.
As the chickens roast, fat and juices continually drip down into a collection pan at the bottom of the oven. A personal rotisserie oven, one that cooks up to two chickens, can create half a cup of greasy drippings. A small commercial oven can hold anywhere from six to 15 or more birds, producing three to seven cups of oily liquid.
At these low levels, the grease produced is not a problem; employees simply empty out the drip pan when it becomes full.
But some commercial kitchens, like those in club stores, have high-capacity rotisserie ovens roasting 70 or more chickens at a time. That can add up. A high-volume rotisserie oven can discharge up to 70 pounds of grease daily from its roasting chickens.
In these cases, the drip pan system is simply not feasible. Instead, a water bath system removes renderings from the collection pan as the meat cooks. The ovens are plumbed to a supplemental water line, and water flows into the shallow “bath” at the bottom of the oven. The water and drippings drain through an overflow pipe and into a grease trap at the source or to a central grease removal unit.
Thermaco’s Big Dipper grease interceptors are already being used with rotisserie oven installations to prevent oils and fat from entering the sewer system.
Avoiding leaks and clogs
But grease interceptors don’t work if they reach capacity and allow fat, oil and grease to leak into the sanitary sewer system. While an interceptor may appear to be sized properly for your kitchen, if you have a high-volume rotisserie oven, the amount of grease it produces can vary from season to season and even hour to hour.
Demand for hot-cooked meals tends to peak in colder months, and so the number of rotisserie chickens cooked in winter will likely be much higher than in summer. Kitchen operators must take into account seasonal shifts and factors like coupons, discounts and menu changes to help predict surges in rotisserie use.
Rotisserie ovens produce more grease at higher temperatures when they are roasting chickens. After the roasting period, ovens lower to “holding” or “warming” mode. Operators can use this information to help predict which times of day will result in higher grease volume.
If a grease interceptor doesn’t have the capacity to handle surges in rotisserie use, it will back up and allow fats, oil, and grease to pass into the water system. Accurately calculating the amount of grease your commercial rotisserie oven produces throughout the year is key to avoiding costly plumbing expenses.
The automatic solution
One way to prevent grease buildup in source-point grease traps is to install a trap with a digital control unit. Digital systems automatically skim grease from the surface of captured water and direct it to a separate container, which can be easily emptied by staff whenever it gets full.
Thermaco’s 51k Series Big Dipper has a digital control that can be configured specifically for rotisserie operations. The grease trap can be programmed to turn on its water supply and skimmer during temperature increases, and turn it off when the oven is in warming mode, avoiding unnecessary wear and tear on the interceptor.
Automatic features make it easy for any commercial facility operating a rotisserie oven to avoid clogs and backups in its plumbing and stay in compliance with pretreatment regulations.