Yo siempre había sabido que cocinar a bño maría implicaba usar las cacerolas dobles (double boiler), donde la comida nunca entra en contacto con la fuente de calor, sino que es calentada por el vapor que emite el líquido en la parte inferior. Creo que aquí se refiere a un baño o inmersión total en agua hirviendo. ¿Me equivoco?
http://pubs.ext.vt.edu/348/348-594/348-594.html
Boiling water bath canning involves packing jars with food, completely covering the jars with water, heating the water to boiling (212 degrees Fahrenheit (F), 100 degrees Celsius (C)), and processing for 5 to 85 minutes, depending on the food product, style of pack, and jar size. Boiling removes the oxygen remaining in the jar, which helps to form a tight seal between the lid and the rim. The heat used for this method of canning is sufficient to kill vegetative bacterial cells found in the food.
The translation workplace 
peer agreement (net): +5
