>DOUGH
https://en.wikipedia.org/wiki/Ancient_Roman_units_of_measurement
Take rainwater kept for several years, and mix a sextarius (546 mL) of this water with a [Roman] pound (328.9 g) of honey.
For a weaker mead, mix a sextarius (546 mL) of water with nine [Roman] ounces (246.6g) of honey.
The whole is exposed to the sun for 40 days and then left on a shelf near the fire.
If you have no rain water, then boil spring water.