On a stretch of California grassland, workers milk 70 Jersey cows and bottle several hundred gallons of milk into quart glass bottles topped with bright yellow caps _ without heating the milk to pasteurize it.
Claravale Farm, two hours west of Fresno, has been producing milk with minimal interference between the udder and the customer for about 80 years. It's one of two licensed raw milk dairies in California, which allows the retail sale of milk that has not been heated to 161 degrees Fahrenheit for 15 seconds.
But even as consumers inspired by the local food movement line up at farmers markets and specialty stores to buy raw milk, pressure on the producers has intensified in California and elsewhere around the country.
"People have been drinking raw milk for thousands of years around the world," Claravale's owner Ron Garthwaite said. "But recently, raw milk has become a biohazard."
Five other states _ New Hampshire, Pennsylvania, Idaho, Vermont and South Dakota _ have adopted stricter standards to regulate the amount of bacteria in unprocessed milk in the past three years, according to the Raw Milk Survey released last month by the National Association of State Departments of Agriculture.
And states have cracked down on small unlicensed farmers selling raw milk to friends and neighbors. Three people were arrested in California this week for allegedly producing and selling raw milk without a license. They ran a herd share, in which several people split ownership because an animal's owner can legally drink its raw milk without state inspections.
Raw milk has been consumed since about 10,000 years ago, when goats were first domesticated, but only 1 to 3 percent of Americans consume it today. Federal law prohibits the sale of raw milk from state to state, but allows states to regulate its sale within their borders.
Thirty states allow some sort of raw milk sales: 13 restrict sales to the farm, 12 allow for retail sales and the other five have a combination of regulations.
Raw milk enthusiasts say pasteurization _ the process of heating milk to kill disease-causing bacteria _ kills bacteria beneficial to human health and argue that unprocessed milk is fresher, full of nutrients and tastier.
The Centers for Disease Control and Prevention, however, warns that raw milk "can make you very sick or kill you." According to the CDC, raw milk can be contaminated with bacteria such listeria, salmonella and E. coli.
Raw milk producers, who are subject to extensive pathogen testing, say their product is unfairly maligned.
"Government officials want to force us to create a sterile environment. What they don't understand is that our customers don't want industrial milk, they want a living product," Garthwaite said. "It's ironic when you can freely smoke cigarettes and drink alcohol, yet the government tells you raw milk is supposedly deadly."
Michael Marsh, chief executive of Western United Dairymen, which lobbies on behalf of California's dairy industry, said the primary concern among conventional dairy producers is that raw milk can give all milk a bad image.
"Consumers don't always discriminate between the two," Marsh said. "They just hear `milk' and that it made somebody ill. Our concern is, if people get sick from raw milk, it stains the rest of us and demand for all milk goes down."
From 1998 through 2008, the CDC reported 86 outbreaks with 1,676 illnesses due to consumption of raw milk or raw milk products. During that period, no deaths were attributed to drinking raw milk, according to the agency. Two deaths occurred due to consumption of queso fresco, cheese made with unpasteurized milk.
During the same time period, pasteurized milk products _ which are consumed by the vast majority of Americans _ caused 27 outbreaks with 2,494 illnesses and 4 deaths.
The lack of retail availability of raw milk has led consumers to flock to so-called herd shares.
But California has recently moved to shut down shares in El Dorado, Placer, Riverside and Los Angeles counties, said Department of Food and Agriculture spokesman Steve Lyle. Local prosecutors have also taken up several cases against herd shares, Lyle said.
"Herd-sharing arrangements where milk is distributed off the property is a commercial distribution subject to state law," Lyle said. "It must be licensed and inspected by the state. It's about making sure the food is safe."
Evergreen Acres Farm in San Jose, which ran a 100-person herd share with 20 goats, has been told to shut down. Owner Michael Hulme said his farm may go out of business, because he can't afford the bottling equipment and other requirements to become a licensed dairy. He estimates there are 70 to 100 herd shares throughout California.
Another farmer told to shut down her herd share _ 2 cows shared by 15 people _ is hoping for legislative help. Pattie Chelseth, owner of My Sisters' Farm in Shingle Springs, wants a bill that would let small producers sell goods like milk and cheese directly to consumers without government oversight.
"It's about a private, contractual relationship between you and your neighbor," she said.
Follow Gosia Wozniacka on Twitter at (at)GosiaWozniacka