At the St. Helena restaurant Press, gone are the days when kitchen staff scraped leftovers into trash bags destined for the landfill.

Instead, the restaurant has installed a state-of-the-art dehydrating system that takes wet food-waste along with other compostable materials and turns it into a dry, nutrient-rich soil additive.

The St. Helena restaurant is the first eatery in the Napa Valley to install the technology, which was developed in South Korea, where it has been in use for 12 years. It has been in the United States for 18 months.

Press’ kitchen staff will never have to cope with flies, rodents and smells or worry about clogging the sewer system with the food waste.

Chef Stephen Rogers said employees have had no trouble adapting to the new technology, which is in a storage room just off the kitchen. “Everyone is really excited about this. We used to throw everything in the trash.”

Rogers said the machine is filled with food waste after all the morning preparation is done. The machine runs twice a day turning about 100 pounds of unfinished dinners and excess trimmings from kitchen prep for a nine-hour sterilization cycle. Paddles inside continuously mix the food waste.

After nine hours, the waste is reduced to 15 pounds of a sterilized nitrogen-rich soil additive that can be mixed with compost or tilled into the soil.

Rogers said they put almost everything in the dehydrator including egg shells, macaroni and cheese, coffee grounds, mashed potatoes, vegetables and bread. It can decompose just about anything. 

Press does not put bones, corn cobs, poultry or meat into the composting dehydrator — but they could. The only things that can’t be put in the machine are glass and aluminum foil.

“What is cool is almost nothing is going into the garbage,” Rogers said.

Press has always been active in recycling and about 90 percent of what had been left at the restaurant is food waste.

The food waste dehydrator comes in five model sizes, with the biggest able to handle around 3,300 pounds of waste.

The unit at Press is the smallest model being marketed by FRG Waste Resources Inc., of American Canyon.

FRG Waste is marketing the technology in Northern California, Oregon and Washington and is operated by Tim Shea, whose business card reads “trash and recycling guru.”

Rogers said the waste at Press is picked up twice a week by local grower Jon Brzycki, when he delivers vegetables to the St. Helena restaurant, next to upscale retailer Dean & DeLuca.

The farmer incorporates the sterile nutrient-rich waste back into his soil.

Rogers said Press decided to use the new technology not to save money, but because it is the sustainable thing to do, and “it’s the right thing to do for the environment.”

Shea added that this system should reduce the restaurant’s garbage costs.

Shea pointed out the system is a closed process. Open the hatch on top after the process is complete and the end products smells like sweet molasses.

Press’ stainless steel appliance could be mistaken for a dishwasher on the outside, but inside the walls are filled with an oil that is heated to 180 degrees Fahrenheit.

The dehydrator makes barely a whisper when it runs.

Shea added that clean up is a snap — wipe off the inside of the lid and seals and rinse off a small wire mesh screen. The equipment is user-friendly.

“It’s a straightforward piece of equipment,” he said.

As an alternative to the FRG technology, some local restaurants trying to be green have been putting their food waste into large plastic barrels that are picked up several times a week by a truck that takes it away to a composting facility.

But such a strategy involves rinsing out the barrels and coping with flies, smells and rodent control.

The starting price tag for the dehydrator starts at around $17,000 or can be leased for about $300 a month.

Besides being used as a soil nutrient supplement, Shea said research is being done to see if the end product can be used as a livestock feed or even formed into charcoal briquettes. “This technology is constantly evolving. It is earth friendly,” Shea said.

Tim Healy, assistant general manager/district engineer at Napa Sanitation, said there is no doubt organic food waste can be a problem to the sewer system.

Large amounts of organic food material puts a strain on a sewage treatment plant’s capacity. It can also lead to a rotten egg smell in the air.

Anything that can be done to reduce the amount of food in the system improves the capacity of a sewage plant, Healy said.

Also, restaurants have grease interceptors that divert grease from the sewer system.

“If a restaurant puts too much food waste down its disposal system, it fills the grease interceptors quicker, and they have to be cleaned more often,” Healy added.