I recently watched "Supersizers Eat Medieval" ... I know .... I really should do this to myself. Every time I go in hoping for a realistic portrayal of medieval food, and almost every time I'm disappointed.
This time wasn't as bad as it could have been. While they did repeat and reinforce some of the usual myths, they did get some things reasonably close to right. Below are some comments on things that were said, done, or shown in the episode - in no particular order.
Trenchers
The show did depict the use of trenchers as a sort of disposable plate, and noted that they would have gone to the poor when the diner was through with them. That's reasonably accurate, though trencher use was not prominent until the late 15th century - which is much earlier than most of the other stuff depicted in the program.
It's also worth noting that, from the accounts I've read, trenchers were made from three-day-old bread (rye?) specifically baked for that purpose. One description of trencher loaves has them as being rectangular, flat, and about 4" x 6" in size. This is in contrast to the show's hosts cutting slices off of a round, apparently fresh loaf.
Lack of Vegetables
Where are the veggies? Contrary to popular belief, and to what was depicted in the program, the wealthy did eat vegetables (and the poor did eat meat, but that's a whole different matter.
Size of Meals
There is definitely something strange going on about the size of the meals - but it's not necessarily the fault of the program. Even medieval accounts had each diner sometimes receiving absurd portions of meat (e.g. 10 pounds). I suspect a large portion of that was passed on to the poor as an act of charity, or it was shared with members of the diner's household, or some such.
Water
The popular belief that nobody ever drank water in the middle ages is repeated. It's simply not true. We can thank the Victorians for this myth.
Beer
I have no idea where the bit about spitting in the beer came from. If someone can point me to a reliable source, I'll accept it (after all, that's one of the ways they (used to?) make fermented beverages from corn in South and Central America (e.g. "chicha").
Average Lifespan
This is one of those ideas that seems to be unkillable. People are always confusing "average life expectancy" with "maximum life span". Yes, the life expectancy of people in medieval Europe was pretty low (e.g. 30 years), but that doesn't mean that no one lived long enough to get old, nor does it mean that 35 was considered old.
The average life expectancy was brought way down due to infant mortality, but if an individual survived childhood then they stood a decent chance of making it to their 60s.
Peacock
At one point in the program, they make a big deal about how nasty peacock tastes, with the implication that medieval people had to be nuts to eat it. It was relatively common though to use a peacock's feathers to dress a capon - thus making a good tasting bird look really fancy. I've also seen a recipe in a medieval French source that called for the roasted peacock to be dressed with the capon's feathers - not to be enjoyed by the noble, but to be served to some unsuspecting diner as a prank. The implication is that medieval Europeans didn't like how peacock tasted either.
Turkey
At one point in the program they are served turkey. Since turkey is a new world bird, it would not have been available for most of the middle ages (possible for any of it, depending on how you define "medieval").
Gilded Gingerbread
This is a strange one. I've seen lots of recipes for gingerbread, but none that call for gilding. There are recipes for sugarpaste that might have been gilded, and I think there is one (late medieval) case where sugarpaste was called "gingerbread" (it was flavored with ginger). I'm curious where they got this.
Leach
At one point they translate "leach" as "licking". Um ... no. Leach (or leshe) is "slice" - both as a verb and a noun.
Marzipan
Marzipan is described as being expensive. This is sort-of true, in that it is made from almonds which were imported, and that (in 1438 for example) a pound of almonds cost almost twice what an unskilled laborer would be paid for a days work. However given what was also being bought for medieval feasters, that's not that extravagant. Marzipan shows up a *lot* in medieval cookbooks.
Barnacle Geese
The stories about what was and wasn't considered to be "fish" in the middle ages are quirky and fun, and it's tempting to say "Look how daft they were!" However I'm inclined to think that the whole bit about beaver tails, barnacle geese, and the like were just a sort of culinary "technicality" to get around religious dietary restrictions.
For this particular claim, the Wikipedia page on Barnacle Geese has the following note:
At the Fourth Council of the Lateran (1215), Pope Innocent III explicitly prohibited the eating of these geese during Lent, arguing that despite their unusual reproduction, they lived and fed like ducks and so were of the same nature as other birds.
Like I said, it could have been worse. They didn't bring up rotten meat at all.
