According to Maimonides, poison in wine was particularly dangerous and difficult to detect. "The trick is easily done by mixing the poison with wine," he wrote, "because the latter as a rule covers up the poison's appearance, taste, and smell, and speeds it up on its way to the heart. Whoever drinks wine about which he has reason to suspect that someone has tried to outwit him is certainly out of his mind."
In the late sixteenth century, the powerful minister of Spain, Gaspar de Guzm·n, Duke of Olivares, was evidently well aware of the dangers of poisoned wine. According to a report in the Medici Archives in Florence, Olivares, when dining in the city of Valencia, "having taken his first drink and tasting a very unnatural flavor in the wine, he feared poisoning and jumped away from the table in a great fury asking for remedies. Meanwhile the wine steward, having heard what was going on, reassured His Excellency that the bad taste resulted from his not having rinsed the wine flask well after washing it with vinegar and salt. When the steward then preceded to drink the same wine, he [Olivares] finally calmed down."
Girolamo Ruscelli agreed with Maimonides. He wrote the 1555 book The Secrets of the Reverend Maister Alexis of Piemont, Containing Excellent Remedies Against Diverse Diseases, Wounds, and Other Accidents, with the Maner to Make Distillations, Parfumes, Confitures, Dyings, Colours, Fusions, and Meltings, which swept across Europe in numerous translations and editions. In a section called "For to preserve from poisoning," he noted, "You must take heed that you eate not things of strong savor, or of a very sweete taste, because that the bitternesse and stench of poisons in this maner is wont to be covered, for the over-sweet, souer, or salte thing mixed with poison, doth hide the bitternesse of it."
Ambroise Paré, physician to four kings of France, wrote in his 1585 treatise on poisons, "It is a matter of much difficultie to avoid poisons because...by the admixture of sweet and well-smelling things, they cannot easily bee perceived even by the skillful. Therefore such as fear poisoning ought to take heed of meats cooked with much art, verie sweet, salty, sowr, or notabley endued with anie other taste. And when they are opprest with hunger or thirst, they must not eat or drink too greedily, but have a diligent regard to the taste of such things as they eat or drink."
For thousands of years, kings hired tasters to test each dish before it reached the royal mouth. However, poisons—even a hefty dose of arsenic—don't necessarily work instantly. Contrary to what we see in film, the victim of poison didn't swallow something, grab his throat, and hit the floor dead. The length of time required for the first symptoms (abdominal pain, vomiting, and diarrhea) to appear varied greatly depending on the individual's height, weight, genetics, general health, and how much food was already in the stomach, which would slow the poison's absorption.
One of the few recorded examples of this phenomenon occurred in 1867 when a group of twenty guests sat down to a meal at an Illinois hotel and ate biscuits mistakenly made with arsenic instead of flour. One guest fell ill shortly upon rising from the table, while the others became sick over several hours, although they all consumed the arsenic at the same time. All the victims had nausea and diarrhea, but other symptoms varied, including a burning pain in the gut, a constricted throat, cramps, and convulsions. One victim had diarrhea and difficulty urinating for several weeks. None died.
Certainly, the royal family wouldn't wait at the table an hour or two after a taster tested their meal to see if he started retching—their food would be stone cold. Evidently, kings and their physicians weren't aware of this time lag and expected poisoned tasters to start gagging and vomiting immediately. They also must have relied on the taster to test for unusual flavors or textures.
According to Maimonides, it was preferable if the taster—or a host whom the king suspected of unkindly intentions toward him—took a great heaping helping of the food rather than a polite nibble. "Someone who wants to guard himself against someone else whom he suspects," the philosopher wrote, "should not eat from his food until the suspect first eats a fair quantity from it. He should not be satisfied with eating only a mouthful, as I have seen done by the cooks of kings in their presence." To prevent the poisoning of his hard-won son and heir, the future Edward VI, Henry VIII had tasters stuff their faces with the young prince's milk, bread, meat, eggs, and butter before the boy took so much as a spoonful.
By the Middle Ages, the tasting of the king's food developed into a complicated set of protocols, rituals, and safeguards. Testing began in the royal kitchen. A 1465 report of the banquet held to celebrate the installation of George Neville as Archbishop of York described the numerous assays, or tests, of the dishes. "In the mean tyme the Sewer goeth to the dresser," the author explained, "and there taketh assay of every dyshe, and doth geve it to the Stewarde and the Cooke to eat of all Porreges, Mustarde, and other sawces... And of every stewed meate, rosted, boylde, or broyled, beyng fyshe or fleshe, he cutteth a litle thereofe...and so with all other meates, as Custardes, Tartes, and Gelly, with other such lyke."