Thieves stole fryer grease from a Keys chowder house, cops say. Here’s what it could mean

Police in the Florida Keys are asking restaurants to be on the lookout for thieves targeting grease traps that collect their used cooking oil.

There’s a market for the oil — and not just for making batches of croquetas or fries.

The used fryer grease has become a sought-after commodity for both legitimate collection businesses and those looking to make quick cash on the black market. The new value comes with the rise of biodiesel, a fuel made from renewable sources like cooking oil, animal fats and soybean oil.

Monroe County sheriff’s deputies on Tuesday arrested two men they say siphoned about 300 gallons of used cooking oil from the back of Herbie’s Bar and Chowder House in the Middle Keys city of Marathon.

READ MORE: Grease frying food at Miami eateries recycled into biodiesel fuel to slow climate change

Reynier Rivero Gonzalez, 36, of Hialeah, and Yadriel Luis Zaragoza, 24, of Miami, remained in jail on grand theft charges as of Wednesday afternoon — both held on bonds of $5,000.

The men were driving an unmarked white van when deputies pulled them over around 12:30 p.m. Tuesday after witnesses reported them taking the oil, said sheriff’s office spokesman Adam Linhardt.

Deputies said the van smelled of cooking oil, and the inside of the vehicle was covered in oil. Two 250-gallon containers containing cooking oil and a large pump were found inside the van, Linhardt said.

A pump is shown in the back of a van that Monroe County Sheriff’s Office deputies say two men used to steal about 300 gallons of cooking oil from a Florida Keys restaurant Tuesday, July 4, 2023. MCSO
A pump is shown in the back of a van that Monroe County Sheriff’s Office deputies say two men used to steal about 300 gallons of cooking oil from a Florida Keys restaurant Tuesday, July 4, 2023. MCSO

The restaurant owner told deputies he contracts with a company to collect and recycle the used cooking oil, and his kitchen workers told him no one from that company came by that day.

The owner of the oil collection company confirmed he didn’t send anyone, and he wanted to press charges against Rivero Gonzalez and Zaragoza, Linhardt said. He told deputies that the amount of oil the men stole was worth around $1,290.

Monroe sheriff’s Lt. Nancy Alvarez, the lead investigator in the case, is asking other restaurant owners to contact the sheriff’s office if they also have been targeted. She believes thieves are hitting Keys restaurants for the oil and selling it to buyers on the mainland.

“What else are you going to do with it?” Alvarez told the Miami Herald/FLKeysnews.com.

If anyone has information on the case or similar cases, Alvarez wants to hear from them at 305-481-8060.

Cooking-oil theft isn’t just happening in the Keys.

In April, for instance, authorities in western New York arrested two men accused of stealing cooking oil from restaurants in the middle of the night. Prosecutors say they resold the stolen cooking oil — which “can be refined” into biodiesel fuel for $4 to $5 per gallon — and made thousands of dollars.

What is biodiesel

According to Clean Fuels Alliance America, a renewable fuels lobbying group, the use of biodiesel has become so prevalent in the past few decades that almost 80% of new diesel-powered vehicles are approved to use a blend known as B20 — meaning it’s a mixture of conventional diesel and 20% biodiesel.

Biodiesel is made by separating glycerin from the vegetable oil or animal fat.

The process not only produces the fuel, but the glycerin left behind can be used to make products like soap, according to the Clean Fuels Alliance.