HUDSONVILLE, Mich. (WZZM) -- For several years, diesel fuel has cost about 40 cents more per gallon than regular unleaded gasoline.

When fuel prices first started spiking, a market for home brewed biodiesel emerged in 2007. It can be a lot cheaper, but there are competing views on its safety, and whether there are environmental consequences.

Creating biodiesel is relatively simple. You can use vegetable oil, canola oil, or head to a restaurant and ask for leftover oils from the fryer. But after you make the fuel, there's leftover gunk. And what to do with it is where the debate lies.

It starts in the fryer of Cliff Westendorp's kitchen at the Hudsonville Grille. No, not the making of an appetizer to fuel the body.

"We're making three to five gallons of fryer oil per week," said Westendorp.

After he mixes it with diesel, this is fuel for his truck.

"It basically cost me $1 per gallon versus $4 per gallon," he said.

Westendorp doesn't just brew delicious entrees, he home brews biodiesel.

"I filter the oil twice before it goes into the tank," he said.

Biodiesel is a renewable fuel made from either new soybean or canola oil or waste restaurant oil. Westendorp puts his waste right back in the original five gallon jugs and hauls them to his auto shop.

There sit two large tanks; he collects 35 gallons of waste oil in one tank.

"I let it sit in here for a few days to settle," he said.

Next, he mixes it with 20 gallons of diesel in the other tank.

"Then I circulate it through two filters. That cleans it, then once it's mixed really I'll put it right in the truck."

This is one method of home brewing which took off in Michigan in 2007, after the price of fuel rose dramatically.

"If you can collect the oil, you can make the biodiesel for $1.67 a gallon," said Dennis Pennington, a bioenergy educator at the Michigan State University Extension Office.

That's the other type of home brewing Pennington is talking about. He makes biodiesel, and a lot of it for his program, which is located in a building a few miles off campus.

They actually grow their own crop, and use an oil press.

"We have to squeeze the oil out of the seed," he said.

But Pennington can also whip up a batch of real home brew, and he measured everything out to show us how. It starts with the oil. If you use fryer oil, you need to first strain the particles out.

"I drew one milliliter of the clean oil and put it into this beaker," he said. Then he mixes in an alcohol.

"We would use methanol," he said.

Next he adds a one percent mixture of sodium hydroxide and a color corrector. Once the oil is filtered, it ends up in some type of tank, depending on how much you want to make.

That's where the brewing process can begin. It takes about 2.5 hours. The tank must have a funnel at the bottom so the byproduct can settle. The final result: Biodiesel on top, byproduct on the bottom.

"It's caustic and dangerous and you have to know what to do with it," said John Miller.

Miller is a chemist and fuel expert at Western Michigan University who loves talking biofuels.

"It's one of the things that gets me up in the morning," he said.

And he'll be honest.

"I would recommend that they not home brew," he said.

He was all for this method when the boom happened, but now he believes safety and environmental impacts of the byproduct are too great.

"This red layer is the glycerin layer," he said, pointing to a jar in his lab.

The non-biodiesel waste stream consists of glycerin, methanol and the base catalyst. Miller says it's basically drain cleaner, and says the methanol component is poisonous.

"Our fear is that they're putting it down the drain, our fear is that they're land applying it. But we really honestly don't know," he said.

Pennington says dumping it down the drain is of concern, but not land application. He says it can be applied to farmland as a fertilizer source. Some do keep the glycerin to make soap and cosmetics.

"I don't have any concerns regarding home brewing in terms of environmental or safety concerns," Pennington said.

Pennington says very small amounts of methanol and unspent catalyst are left in the byproduct. In commercial production, facilities are in place to remove those impurities and properly dispose of them. In small scale production, Pennington says it is not cost effective to do this.

Whether or not you think it's environmentally wrong, it is legal.
Now you can decide if this alternative fuel is worth the cost to save some serious cash.

The National Biodiesel board told us they do not recommend dumping glycerin in the ground. The U.S. Environmental Protection Agency emailed a statement that says: "We do not have enough information on biodiesel byproducts to determine whether it may present environmental concerns that require it to be managed with restrictions. We believe that this product may have levels of alcohol (which is a flammable liquid) that would cause it to pose a hazard when managed improperly. That is to say that the product could ignite if managed improperly. "

A Kent County Regional Wastewater Treatment Facility spokesperson said they've never had anyone drop off the byproduct before, but said they would take it in a small quantity if someone did.

For more information on the biodiesel industry, head to

According to the National Biodiesel Board, biodiesel has grown into a large commercial industry. There are currently 200 commercial biodiesel producers across the country that produce more than one billion gallons a year.

Nearly 80 percent of auto manufacturers selling diesel vehicles in the US warranty their vehicles for 20 percent biodiesel.

You can also find Retail locationsacross the country where biodiesel is sold at the pump.