The string was untied, the satchel opened... A whiff of fetid decay escaped the bag and quickly entered restrained, unwilling nostrils...
Trial by cheese—also known as la souffrance de roquefort, French for 'the Roquefort anguish' or 'the Roquefort torment'—was an obscure witch-hunting technique used in the Middle Ages which involved exposing the subject to a properly christened specimen of Roquefort cheese.
Due to the lack of pasteurization in the process of creating Roquefort cheese, listeria infections and other fun maladies had a small but non-negligible chance of occurring. Combine that with the bootleg cheesemongering trade of the late 16th century underground, and the general carelessness of the French when it comes to communicating recipes to the English, and one suddenly has a
metric imperial assload of readily available poor-quality cheese. Of course, the national sport being the systematic hunting and disposal of witches, sketchy Roquefort was quickly put to use as yet another alleged method of discerning witches from more agreeable and less preternatural women.
The trials usually went more or less as follows. The accused was to be restrained in a seated position, whether by rope bindings or by live men with their faces covered. A carrier would then, in presence of onlookers, was bring out a bag of Roquefort: specifically, one that had been blessed by a local priest and then left out in the sun for a full day, if not longer. After sufficient exposure to the smell, a large piece would then be broken off and fed to the suspected witch. If the woman refused to eat the cheese, or vomited at any point, she was deemed a witch—the general justification was that witches would not be able to ingest the bacterial culture in the cheese after it had been properly blessed—and to be burned at the stake promptly afterwards.
Unfortunately, this method was quickly deprecated and retired due to tendency of the cheese to simply cause horrible discomfort to the subject, and not actually leads to many witch confirmations. Despite looking good on paper (if you squint really hard), in practice, more reliable witch-producing methods were preferred to this one, and the trial by cheese was quickly forgotten. However, there were recorded cases of the occasional deaths and/or miscarriages of those women who had survived the test, which confirms the potential presence of listeria in the rancid cheese.
The almost ironically named 'trial by cheese' has since been regarded by historians as an unfortunate loss of life, a pointless waste of cheese, and also a complete fabrication.