Since 2006, the U.S. Food and Drug Administration has stepped up enforcement against dairy farmers whose product, the agency says, poses a significant risk to public health. And Pennsylvania - the country's fifth-largest dairy producer and home to many traditional Amish and Mennonite farms - has become a flash point for the conflict.
But for raw milk devotees, Allgyer - who declined to be interviewed for this article - is just the latest farmer to fall victim to a federal law that they say doesn't make sense in today's world.
"He is being treated as if he were a drug lord," said Jonathan Emord, a lawyer representing Allgyer's customers in Maryland. "This is fresh milk we're talking about."
Federal law has prohibited state-to-state sales of raw milk since 1984, while allowing states to decide what can be sold within their borders. In Pennsylvania - one of 12 states to allow them - more than 110 dairy farms hold raw-milk permits but must submit to rigorous government inspection every three months.
Unpasteurized milk can contain dozens of harmful pathogens such as E. coli, salmonella, and those that cause typhoid and tuberculosis, the FDA says. And according to the Centers for Disease Control and Prevention, more than 1,007 illnesses, 104 hospitalizations, and two deaths were traced to consumption of raw milk between 1998 and 2008.
"The actual number of illnesses is almost certainly higher, but not all cases recognized are reported," FDA spokeswoman Siobhan DeLancey said.
Raw-milk enthusiasts maintain that the benefits far outweigh the risks. Pasteurization - a process by which milk is briefly heated to 161 degrees or more before being chilled - kills off not only bad bacteria but also the good, they say. The procedure leaches vitamins, enzymes, and taste from the milk, they say.
It took Liz Reitzig, a Maryland mother who routinely paid more than $6 per gallon to have milk from Rainbow Acres shipped to her home outside Washington, only one sip of the creamy, mouth-filling alternative for her to swear off what she called "supermarket swill" for good.
She now talks about unpasteurized milk with the same cultlike zeal shared by many of its other fans - a mix of foodies, naturalists, and health-conscious consumers. On Internet message boards, they speak of the "dead" and "alive" versions of milk in slogans that echo the language of religious transubstantiation. Some even contend raw milk can cure autism.
"None of us is going back to pasteurized milk. It's a dead product," Reitzig said days after the FDA filed its case against Rainbow Acres. "We can't go back to drinking watered-down chalk."
The raid on Allgyer's farm has left Reitzig and other customers in a tight spot.
In recent years, the FDA has launched similar investigations against unpasteurized-milk sales at California food co-ops and on Midwestern farms. A YouTube video of a raid on a California business last year showed agents - with guns drawn - pacing among coolers of milk intended for customers.
Mark Nolt, a Mennonite dairy farmer in Newville, Cumberland County, has watched these developments with growing concern. Known among those in the movement as the "Rosa Parks of raw milk," Nolt opted in 2007 not to renew his state permit, saying government oversight conflicted with his community's belief system.
But after Nolt ignored several government cease-and-desist notices, authorities led him from his property in handcuffs. The next year, dozens of protesters flocked to his trial, where, defending himself, he refused to enter a plea or pay any of the more than $4,000 in fines.
The Rainbow Acres case, which made its way into a Philadelphia courtroom last month, has played out along similar lines. Government lawyers are seeking an injunction to shut down Allgyer's raw-milk business. A judge has yet to set a date for a preliminary hearing.
Like Nolt, Allgyer does not have a license to sell raw milk in the state. Instead, his customers participated in a "cow-share program" - an increasingly popular loophole around government restrictions.
Instead of buying the milk directly, customers pay an up-front fee to buy a piece of a cow. They are then entitled to a portion of that animal's future dairy yields. (The Pennsylvania Department of Agriculture said it did not view unpermitted cow-share programs as illegal.)
The FDA targeted Allgyer, though, based on where - not how - he was delivering his milk. After stumbling across an online message board that his customers used to coordinate purchases, undercover investigators placed 23 orders for unpasteurized milk between December 2009 and March, each order to be delivered outside the state.
In electronic messages to his consumers, the Amish Allgyer spoke of making trips to Maryland late at night to avoid detection, according to government court filings. At one point, he advised customers not to share information about the buying group with doctors or government agencies.
Three years removed from his own legal problems, Nolt finds the lengths to which Allgyer's farm had to go to deliver its milk exasperating.
"In today's world, with the kind of inspections we have, there's no reason to be afraid of raw milk," he said.
Bucks County dairy farmer Mike Tierney agrees that the laws are outdated but worries that rogue operations like Allgyer's could tarnish the entire industry.
"All it takes is for one outbreak from one of these farms and all of us get a black eye," he said.
Instead, he maintains, dairy farmers should work within current legal confines while also working to reform them.
On Tierney's Birchwood Farm in Upper Makefield Township, each gallon of milk goes straight from the udders of his 30 Jersey cows into a system of stainless-steel pipes that deliver it to an on-site cooling tank for bottling. Cows are tested for all manner of bacteria; his farm's standards, he says, are more rigorous than the state's.
He keeps his permits up to date and remains ready for inspections at any time.
That attention to detail has paid off in business. On a recent afternoon, one car after another - many bearing license plates from New Jersey, which prohibits sales of raw milk - filed into his farm store parking lot to pick up gallons of milk as well as cheeses, yogurts, and ice cream made from his unpasteurized product.
"The regulations are hard," Tierney said. "But most of them exist for a reason."
All except one: the interstate sales ban, he argued.
On Monday, more than 500 of Allgyer's customers and supporters, and one dairy cow, descended on Washington to protest the law behind the FDA action against him. The crowd - an unlikely mix of foodies, concerned mothers, and libertarians - donned T-shirts with slogans such as "The revolution will not be pasteurized."
Though not at the event, Rep. Ron Paul (R., Texas), the presidential candidate and outspoken libertarian, took the occasion to reintroduce a bill that would eliminate the interstate sales ban. Echoing recent statements on what he describes as "pasteurization without representation," he criticized the FDA for throwing roadblocks in the way of small businesses.
"If we are not even free anymore to decide something as basic as what we wish to eat or drink," he said, "how much freedom do we really have left?"
For a video tour of raw-milk production at Mike Tierney's Bucks County farm, go to www.philly.com/watch_milk
Contact staff writer Jeremy Roebuck at 267-564-5218, firstname.lastname@example.org, or @inqmontco on Twitter. Read his blog, "MontCo Memo," at www.philly.com/montcomemo.