Another billboard has claimed the corner of Van Ness and California. "It's the Cheese," it declares. A tourist in Hawaiian print is posing with an orange chunk of processed variety found in any supermarket. Large commercial cheeses like these aren't threatened by mandatory pasteurization, but if new regulations pass, what will happen to the quality artesanal ones? Their market has been expanding all over the state.

So far, regulations have allowed the sale of cheese made from raw milk, as long as it's aged more than 60 days. Otherwise, pasteurization is the rule.

For quality artesanal cheeses, pasteurization can be a problem. Cheesemakers who pasteurize, but still care about flavor, heat the milk to 144 degrees Fahrenheit for 30 minutes, while those concerned more about time heat it to 162 degrees for 30 seconds. If done the "bad" way -- quickly at 162 degrees -- the curd is left with a burnt flavor, or not much flavor at all.

"When milk is boiled," explains Sal Antonin of 24th Street Cheese Company in the San Francisco, "or if it's slightly boiled or heated, it loses the 'barnyard' taste. The flavor is gone. The flavor of real good old cheese disappears when it's pasteurized." No barnyard, no flavor, and that makes all the difference in the cheese world.

And what a world it is becoming in California. We are the nation's largest farming state, with cheese being the fastest growing dairy product. We threaten to overtake Wisconsin with a steady increase in production of commercial and artisanal cheeses.

The diversity of our cheeses mirrors the ethnic diversity of our state. We produce everything from Jack to Cheddar, to Mexican Queso Fresco, to European-style cheeses like Gruyere. Ever heard of a Humboldt Fog that melts in your mouth with a tang? Or what about Laura Chenel's aged crottins that compare closely to the ones produced in France?

California cheeses have been getting better and better -- and no, they're not all pasteurized.

So what if cheesemakers were faced with mandatory pasteurization? Richard Tarlov, Vice President of Merchandising for Oakville Market, has strong feelings on the subject. "That would be the worst thing that could happen in the 20th Century," he says, laughing. "Pasteurization is not the answer. It would set a new standard and ruin flavor in the process, while we struggle through another decade or two of occasional flare-ups of problems and realize that we'd have to address them in other ways."

Keeping cheese safe and sanitary before it hits the tummy is not assured solely by pasteurizing it. There are other considerations, like the places at which milk is moved or stored, temperature maintenance, and the health and hygiene of livestock and feed. Yet another outbreak of bad cheese just might be the perfect excuse for the Department of Food and Agriculture to lean towards mandatory pasteurization.

The American Cheese Society, which represents many small-scale and specialty cheesemakers, is taking no chances. In short, they're sticking by their cheese, local and imported, and lobbying against any threats of pasteurization. They say a big "NO" to scalded milk, which they claim would be "an unnecessary hardship on those cheesemakers dedicated to safe and healthy practices."

Complying with the new regulations would be expensive for those cheesemakers that don't pasteurize their milk and age their cheese longer than 60 days. For one thing, you need to have the equipment to pasteurize, and equipment can be hard to find, expensive, and costly to maintain. Some producers retrofit machinery or buy it used. Cypress Grove, which works out of McKinleyville in Northern California, upgraded from a 150-gallon pasteurizer to a 600-gallon used machine at a cost of $6,000, not including installation. For the larger companies who mass produce and package cheese like the kind you see on billboards, the price of machinery is no problem.

"It's already expensive to make cheese," Tarlov says. The process of aging cheese is where the character comes in, and that can be very expensive. That's why there's so much cheese in this country that is sold in the fresh category -- fresh meaning not aged, and therefore, still full of water. It's very simple to calculate the cost and margin. It's when you age the cheese (remember, it doesn't have to be pasteurized if you are patient enough to wait 60 days), and it loses a third to a half of its weight, that the calculations get messy. If laws required pasteurization, who would bother with all that?