The explosions and white-hot fires that sometimes follow should come as no surprise. Over the years, narcotics detectives have hung several nicknames on the laboratories of these amateur chemists: "Beavis and Butt-head labs," a reference to the moronic cartoon characters, or "coffeepot labs" because that's what crank often is cooked in.

More recently, drug cops have taken to calling them "user/dealer labs" -- those where the meth cooks make fairly small batches of crank, use most of it themselves, then sell portions to buy the ingredients to make more.

Whatever they're called, there are lots of them. In the entire Central Valley, more than 260 small-time labs were busted in 1999, an average of five a week. In Stanislaus County alone, 53 such labs were taken down in 1998. The number jumped to 70 last year, and in the first four months of this year alone, 50 meth-manufacturing arrests were made.

A standard Beavis and Butt-head lab involves three or four people who pool money to buy supplies. They manufacture about an ounce at a time, which costs roughly $140 to produce. Ten boxes of pseudoephedrine pills cost $80, and 2 ounces of iodine and red phosphorus run about $40 combined. There are several other ingredients used, such as Coleman fuel, sodium hydroxide and hydrochloric acid.

The mixture is cooked from four to eight hours, often in coffeepots, though a few cooks graduate to glassware. Once it cools, other chemicals are added to help separate the meth from toxic liquids. Red phosphorus and iodine are filtered out, leaving an ounce of crank worth about $400.

Valley cops say there are common elements to many lab sites, from the preferred brand of beer consumed by the cooks (Bud Light, followed by Corona), to the linens of choice used to strain the meth (the Martha Stewart line because of its high thread count and availability). But there can be decided variations in the process, depending on how resourceful -- or how pathetically desperate -- the meth makers are.

One variation is called the "Nazi method" because it supposedly mirrors a meth-making procedure followed by the Germans during World War II. Instead of hydriodic acid, the Nazi method uses anhydrous ammonia, a nasty substance that can produce a poisonous gas if its liquid form is released into the air. Central Valley drug fighters say they have taken down maybe eight of these labs in the past two years. Five of them were traced to a man from Missouri who had moved into a trailer park near Fresno and was teaching this method, which is popular among small labs in the Midwest.

Another method is more earthy. In some areas, so much meth by-product has been dumped into the soil that cooks are excavating hundreds of cubic yards of earth from the sites to process the dirt and extract the chemicals to make meth. "It looks like a moonscape," says Bill Ruzzamenti, a DEA special agent and director of a Valleywide meth task force. "It's mining for meth."

But Ruzzamenti can top that for stomach-turning absurdity: In some sites -- appropriately, if inelegantly, dubbed "pee labs" -- agents are finding that the ingredients include human urine.

"If you take the urine of a speed freak, and process it , you get back about 40 percent of the meth he used because the body only absorbs so much," he says. "So they are processing their own pee. It's unbelievable."

Suspending disbelief, however, is part of the job in hunting down small-time meth makers.

"We were surveilling this guy one night who kept coming out of the house to smoke, so we figured he was cooking," says Stanislaus Drug Enforcement Agency detective Steve Hoek. "The next morning when we hit this guy, we find him upstairs. He's surrounded by about 70 or 80 open quart jars of ether and acetone he was using to separate this meth. And he's sitting there on the floor smoking. The whole place should have blown up. I've seen a lot of stupid s*** in this job, but that was amazing."

Hoek tells of another man who hid containers of red phosphorus in the attic over his garage. The chemical is heat sensitive, so it began to turn to white phosphorus, which is air reactive. It started a blaze so hot the fire department had to give up and let the house burn.

Some meth makers don't reserve all their stupidity for chemical mistakes but save some for poor geographical choices: In the past few years, four labs have been taken down within three miles of the Stanislaus County Sheriff's Department. One lab hidden in a bamboo field on the same street turned out to be one of that county's largest lab busts.

"Once in a while, I'll be standing in the [Sheriff's Department] parking lot, and I can smell it," says Stanislaus County sheriff's Sgt. Doug Leo. "They'll cook anywhere. Nothing is sacred anymore."

What small-time meth makers lack in smarts, however, they make up for in numbers. On a day in late spring, narcotics detectives Mark Ottoboni and Pat Sullivan put on white suits, old shoes and two pairs of gloves apiece and begin sifting through the ashes of a house on Paradise Road in west Modesto.

Just outside the burned-out frame, they stack the evidence: charred metal containers of Coleman fuel, blackened glass flasks, a heating mantle and several partially melted, 5-gallon buckets of white and yellow powders. The yellow powder is crank; the white substance is something used as a cut.

This has become a typical day for Ottoboni and Sullivan. There are so many lab mishaps, the detectives spend most of their time searching charred labs and lab dump sites for evidence instead of combating manufacturers.

"I've been working labs since I got here four years ago," Ottoboni says. "There are so many now, it's hard to proactively work them. When I go to a lab, it takes about two days to do the reports, process evidence and run background checks on  to see if they've bought chemicals."

No one was at the Paradise Road residence when firefighters arrived at 2 a.m. the night before, the house fully engulfed in flames. Those responsible have, more than likely, moved somewhere else to cook. Crank labs can be moved quickly from place to place. The coffeepot and chemicals fit into a square, plastic storage tub that easily fits into a car trunk. Meth cooks can drive to a new location, set up shop and leave six hours later with a fresh batch.

The landlord is largely uncooperative; he tells Ottoboni he rented the house to someone named Guadalupe. No last name. No rental agreement.

"Take one down, three more pop up," Ottoboni says, as he picks through the remnants of a back bedroom. The floor is covered in blackened soot, burned folded clothes, pots and pans, magazines and propane bottles. He picks up a broken piece of a glass beaker, and the toxic red sludge eats through his first layer of rubber gloves. This hadn't happened to him before. The sludge is a mixture of red phosphorus, iodine and pseudoephedrine.

Sullivan walks around the house, looking for clues. He examines the mangled tin sheeting that walled the largest room. The force of the fire, or an explosion, sharply indented the sheeting, shooting rusty nails across the yard. The only thing left standing is a charred gas water heater, which probably helped start the fire.

"We've seen it a few times the last couple years," Sullivan says. "Gas water heaters have a flame. Acetone and denatured alcohol are extremely flammable. The fumes are heavy and hug the ground."

Basic chemistry.