This past March I spent a long weekend in Montreal with the family to celebrate my birthday. At the end of the trip my mother and I took a side excursion to the city’s southeastern suburb of Saint-Bruno-de-Montarville to visit Les Laines Biscotte.

Though the store carries a wide variety of yarns from diverse producers, it may be best known for its sock yarn. On the website, you can join Biscotte’s Mystery Sock Club to receive a skein of sock yarn and a pattern every other month. In-store, how...