LEWISTON — At its most basic, soap-making is a combination of caustic lye and a fat of some kind, mixed with a chemist’s precision.

“It’s kind of magical,” Lewiston’s Tracey Miller said. “It’s chemistry, which is sort of ironic, because chemistry was probably my worst subject in school. You start out with these very different components, but you wind up with something wonderful.”

What began as a fun day trip for Miller and her mother years ago has turned into a neat little business called Second Story Soapworks. Operating out of her White Street home, she makes custom soaps she sells through a few local shops and online at Etsy.

It’s given her a hobby she enjoys, plus a little extra income. And it makes her house smell really nice.

“It’s taken me a while to learn how to do it without letting it take over the whole house,” she said. “Also, I have to make sure the kitchen is totally clean first, which is hard with kids.”

Miller said she and her mother took a soapmaking class for fun a few years ago. A professional graphic artist, she’s taken many similarly creative classes before, but this one stuck.

“I knit, I sew, I’ve done batiking,” she said. “I just like to try new stuff, and my mom’s the same way. So we did this together, and we both got totally hooked.”

At first, they’d make soaps together, giving them as gifts to their friends. She stopped for a while when her children were young and her mom moved on to other things.

“But I decided — to make a little money and just stay creative — that I’d get back in to the soaps,” she said.

She began selling them in one local shop and then others. People loved the soaps — so much so that she had trouble keeping up with demand.

“I wanted to keep it a microbusiness while being able to live my life,” she said. “I scaled back a lot and turned down a couple of offers to distribute them more widely.”

It’s now running at a scale she can manage. All of the soaps are made in her kitchen and laundry room. They cure in an upstairs closet and are packed by hand in paper and labels she designed.

They come in a variety of smells and mixes. The Maine Coast, a combination of lemongrass, flowers, sea salt and seaweed, is one of the favorites, but she can make custom versions.

“When I first came up with and took it out of the mold, I hated it,” she said. “But my customers love it.”

Others smell like peppermint, ginger or pine.

“I experiment with other things, here and there,” she said.

It’s the melding of craft and science she really enjoys.

“There is a level of precision and attention to detail required but, within certain parameters, I have the freedom to experiment — with different fragrances, herbal additives and oils,” she said.

The lye and the fats are heated to identical temperatures, then thoroughly combined with each other and with the herbs and essential oils. It’s all poured into a mold to be wrapped and allowed to cool slowly. She likes to wrap them in blankets and set them aside in a corner of her dining room.

“They call it ‘putting the soaps to bed,'” she said. “I usually just set it here, and sometimes the cat sleeps on top while it sits. Once it’s at room temperature, you know the chemical reaction has completed.”

The soaps are firm enough to handle after a day or so and have the consistency of fudge. They can be cut down to size, but need to cure for a few weeks before they’re ready to ship.

The pretty bars, smoothly consistent with nice sharp corners, get wrapped in paper and prepped for sale or shipping. Odd or ugly bars get covered with a felt skin and a set of monster eyes — which she also does entirely by hand.

“Honestly, my soaps are not that pretty. I don’t fancy them up. But sometimes a batch is so ugly, I can’t sell them. I love drawing silly faces and wanted to come up with something more for kids. So that’s how I came up with the monsters.”

Do you know a creative person with a technological bent? We’d love to talk to them. Contact Staff Writer Scott Taylor at [email protected], on Twitter as Orange_me or call 207-689-2846.