(translated by u/ralfv)
New to these? Read the introduction first: it explains what is left out on purpose and what the yeast of the time could do.
Source: Nuremberg, Germanisches Nationalmuseum, Hs 3227a, c. 1389 (the miscellany best known for the oldest Liechtenauer fencing text), recipe 1.
Language: Middle High German
Style: Hopped mead; caramelized honey added for colour
If you want to boil good mead, take three parts water and one part honey and let it boil well. And when it is well boiled, take two viertail or more, according to how much mead you are boiling, and carry that into a heated room and set it behind the stove, and let it stand until it gets a little cap; that is then called a tampfel.
After that put hops into the other pots and let it boil well, and stir it constantly and very hard, and do not go away from it, or the mead will catch and turn burnt. And when it is well boiled, put it in a cask and pour the tampfel into it, and let them work through one another.
Item, for the colour take clear honey and boil it very well, and stir it constantly with a piece of wood. And when the colour is well boiled, test it: take a little board and drip it on it. If the drops stand and are hard, it is good. And when it is fine and red, pour it, hot as it is, into the mead. Then let it stand eight or fourteen days. Then you have good mead.
Translation: fyndling.de (CC BY-NC-SA 4.0). It was made from the original-language text as transcribed by CoReMA – Cooking Recipes of the Middle Ages, University of Graz, ms. N2 (CC BY 4.0). That transcription is not reproduced on this page; you can read it next to the manuscript scan via the link below.
Original scan and transcription: fyndling.de/rezepte/n2-001. German-language site; Google Translate works well for reading it.