You’re driving on the Bay Bridge towards San Francisco and you notice a familiar smell: fried chicken. While it isn’t beyond the realm of possibility that KFC could attempt to franchise a restaurant on the bridge, it’s highly unlikely that you can get a two-piece original recipe meal on I-80. So either there’s a chicken dinner sitting on the passenger seat or you’re trailing a B100 powered vehicle.

B100 is one hundred percent bio-diesel; a renewable diesel alternative that can be produced from plant products, animal fats and recycled cooking oil. For nearly four years, a station in Berkeley has been powering engines with the eco-friendly fuel. Two aspiring businesswomen will soon open the first retail B100 station in San Francisco in the Dogpatch neighborhood near Potrero Hill.

About five years ago, a horticulture student and friend at UC Davis exposed Robin Gold to the virtues of bio-diesel. “She worked on the farm, and they were brewing their own bio-diesel in an apple-seed processor,” says Gold. “They were using it to fuel their farm equipment.” Gold made the trip to Davis one day and helped brew the bio-diesel, and it wasn’t long before she bought her first bio-diesel compatible Mercedes-Benz.

Bio-diesel is produced through a chemical process called transesterification. The fat is separated from glycerin and that leaves methyl esters, the chemical name for bio-diesel. The glycerin is a valuable byproduct that gets sold for use in soap and other products. According to the National Biodiesel Board, bio-diesel is lower in emissions than petroleum, less toxic than table salt, and biodegrades as fast as sugar.

In San Francisco, recycled restaurant oil has been fueling MUNI fleets since November of 2007 with the help of SFGreasecycle, a free used cooking oil recycling program introduced by the San Francisco Public Utilities Commission. But there had yet to be a public retail station in the city of San Francisco.

Gold was already a full-fledged bio-diesel consumer when she met Michele Swiggers, her future partner in life and business two and a half years after her first experience with bio-diesel. After settling together in San Francisco, they began to dream of starting a small business and realized that bio-diesel made a lot of sense. “We really liked the idea of having our own business of some sort, and no one was doing the bio-diesel thing in San Francisco,” says Gold. “We just couldn’t believe it, so we thought it was the perfect opportunity for us.” Not having to answer to anybody else was also another motivation.

First, they needed to find a vacant location that wasn’t already zoned for condominiums. “Space was really hard to find,” says Swiggers. “It took nearly a year to find a suitable place that had all the qualities that we needed at a price we could afford.” Even after finding an ideal location, they had to deal with tons of forms and applications. Gold and Swiggers believe that the reason it took so long for a bio-diesel station to open in the city is because of San Francisco’s stringent environmental standards and strict planning codes.

The volume of paperwork was daunting for Swiggers and Gold, and each hurdle challenged their conviction. They had a layout that they thought was going to work, but when that plan fell through, doubts began to arise. “Every time we had a set back we thought, ‘Should we be doing this?’” says Swiggers. “But there’s been a lot of support from the existing bio-diesel community so there’s been a lot of help.”

Dogpatch Biofuels hopes to provide more than just alternative fuel. Swiggers and Gold are striving to provide an educational experience for their consumers. And instead of the typical convenience store selling sodas, chips and bottled water, Swiggers and Gold hope to sell juices, healthier snacks and water bottles instead. To them, being local and sustainable is the key in what they do. “It’s mainly about doing something we love and care about, and we really want to see it done the right way in that sustainable model,” says Gold. “We don’t want to see the bio-diesel market fall to petroleum providers, because their only interest is the bottom line. We don’t want to see palm oil bought in Malaysia and shipped halfway around the world.”

Swiggers and Gold’s station has received overwhelming support from supervisor Sophie Maxwell and the residents of the Dogpatch. It’s no wonder considering that bio-diesel is environmentally friendly and comparable in price and efficiency with petroleum-based diesel. It also doesn’t hurt that the exhaust smells like food. “Some say it smells like chicken, some say popcorn, and others say French fries,” says Gold. For Swiggers and Gold, it’s the smell of success.