As I spend more and more time in the SCA (Society for Creative Anachronism), there is one thing that I am becoming more of a staunch proponent of. That is the hard cut-off of 1600. For those who may not know, the time span studied in the SCA ("Period" or "In Period") ends at 1600 AD. There is what is known as the "Grey Period", which covers 1601~1650, but it's most common usage is in documenting possible names, as records from the Grey Period may include names that were given to a person pre-1600.
Which brings me to Sir Kenelm Digby, born in 1603 and died in 1665. While known of a handful of things, Digby is most notable for "The Closet of the Eminently Learned Sir Kenelme Digby Kt. Opened". This text a common source of mead recipes in the SCA. THIS NEEDS TO STOP! Why does it need to stop? Simple, the text was published by a close associate of Digby's in 1669, 4 years after Digby's death. Looking back on the time span of the Grey Period, you'll see that the publication date falls well outside of that time frame, 19 years outside. Digby, the man, was born in the Grey Period, not before, and his mead recipe was, by virtue of his birth year, in the Grey Period as well. Birth year, possible year of recipe formulation, and year of publication, 3 strikes against Digby as a "Period" source for mead.
Now you may say, "Uji, what do you expect us to do? Digby's recipe is easily approached and made." To that, I present "Tractatus de Magnete et Operationibus Eius", a 13th Century treatise by Petrus Peregrinius. Along with information on magnets, among other things, there is a recipe for a simple mead. One that I've made, and documented here. This mead is made with 3 ingredients: honey, water, and the dregs of a previous mead brew (though, you could easily make a "starter" for the initial batch). Simple as simple can be. The resulting mead is delicious and sweet, with a hearty bit of effervescence*.
If you want me to twitch like I've been plugged into a light socket, tell me that you've made a mead out of Digby. If you want to see a pleased smile on my face, and hear a delighted chuckle, tell me you've made Peregrinius' mead. With some time, and spreading the knowledge, we can hopefully move away from Digby as the go-to source for mead, and instead look to a 13th Century treatise on magnets.
*-Seriously, this stuff is FIZZY. Make sure the brew is thoroughly done fermenting before bottling. Otherwise you may end up with a mess of shattered glass, and sticky mead.