Boiling Oil

1 / 3
Bob Day, right, fastens the clips on the kettles
2 / 3
The Day family reenacts the past
3 / 3
A view of the worm weed distillery

You’ve probably never heard of Fry’s vermifuge. It hasn’t been around for a good many years, but, once, it was a worm treatment. Its main ingredient was worm weed oil, produced from the seeds that grow on worm weed plants. There aren’t any bulk growers of worm weed plants in the U.S. these days because modern chemicals have replaced the oil in medicines.

In fact, there never was much worm weed grown in the U.S., as far anyone can tell, but, for some unknown reason, a worm weed industry came into being in Westminster, Md. (in 1860), triggering the growth of a cash crop on small family farms in Carroll and Frederick counties.

‘Worm seed oil is similar to olive oil,’ said Bob Day, who lives on the Day family farm in southern Frederick County. ‘It’s a basic worm medicine used for animals. It was also used to protect calves’ ears from being licked by other calves. Its official name is chenopodium. You plant the seeds in hot beds in early March in sheltered places. You sprinkle straw on them and then transplant them in May or early June. The plant blooms in late August. It’s about 3 to 4 feet tall and looks like a big tumbleweed.’

Bob’s farm has been in the Day family for more than 200 years, with a history that dates back to land grants issued by Lord Baltimore in the late 18th century. A hundred years later the family started growing worm weed along with their tobacco crops.

‘Back then the hot beds were dug in the woods,’ Bob said. ‘They used horses and harrows to roll the beds. It was a cash crop that went with tobacco. Tobacco is harvested in August. Worm seed is harvested the last week in September through November. It was a way of life.’

In 1970, the Day family rebuilt their worm weed still from used equipment to accommodate the crop, so Bob Day speaks from experience when he describes the harvesting and distilling processes.

Harvesting the worm seed plants was done by hand using a special hand-made two-bladed chopper with a 2-foot-long handle. ‘You would bend the plant at the ground, cut it and leave it there,’ Bob explains. ‘It lays there for seven days and goes from green to brown. The sun makes the oil crystallize in the plant.’

The plants were then loaded into wagons, a chore that had to be done in the early morning, when they were dew-covered, so the seed pods would not shatter. The next step was the distillery, still present on the Day farm, though no longer in use.

Two heavy iron kettles, each eight feet wide and eight feet deep, standing side-by-side on a six-foot platform were used for the first part of the distillation process. A set of chains was placed in the bottom of the kettle. One person stood on the wagon with a pitchfork while a second person stood on the floor of the kettle.

‘You have to pack the weed as tight as you can get it,’ Bob said. ‘You’ve got to stomp it down. When it’s half full you put the second set of chains in, then fill it with more weed to the top of the kettle. Then you put the lid down slowly, making sure no stems show. It’s like using a pressure cooker. Springs are applied to the lid to make it airtight.’

Pipes attached the kettles to a stationary railroad steam boiler (dating back to 1850) powered by a Sun oil burner that also dates to the 19th century. When the kettles were firmly sealed, the steam was turned on for 15 to 20 minutes to soften up the weed. The second kettle was loaded and the steam pressure was increased to release the oil from the seeds. The steam condensed and the combination of oil and water flowed into a collector vat. The oil rose to the top and the water ran off into a concrete trough that emptied into a 1,000-gallon in-ground tank.

‘When the oil and water and plants are still in the kettles you cook them for 90 minutes,’ Bob said. ‘The cooked stuff is called erb. You can use that for fertilizer. Cows can eat it when it’s been cooked but they can’t eat it raw – it’s poisonous. When the kettles are cool, they’re opened up. The chains are used to get the weed out.’

The next step in the distilling process was to fill the in-ground tank with steam to pull the water into the redistill tank where it cooked for an hour until the water was clear. The oil resulting from this process was heavier and of a higher grade. Test bottles gave the operators opportunities to check on the oil production.

‘At the end of the day you collect all the oil by drawing it off in the bottom of the receiving vat,’ Bob said. ‘There could be 100 pounds of oil after a 10-hour distilling process. One hundred pounds of plants per acre represent seven kettles.’

At the turn of the 20th century, the oil was sold to brokers and shipped to the nearby port city of Baltimore for further processing by pharmaceutical companies. In the 1970s it was used for perfumes, with the distilled product being shipped mainly to France and Germany. Today, there is no market demand for it, so there is no worm weed harvest. It’s just another chapter in the centuries-old history of Maryland farming.

Jill Teunis is a frequent contributor to Farm Collector. She lives and works in Damascus, Md.

Farm Collector Magazine
Farm Collector Magazine
Dedicated to the Preservation of Vintage Farm Equipment