This year, I am adding a somewhat archaic bit of brewing equipment to the gear brought out by the Regimental Brewmiester. The yeast ring or gjarkrans is a piece of traditional brewing gear from medieval Sweden and Denmark. This tool resembles a complicated wreath of small pieces of whittled wood. Yeast harvested from one batch of beer to the next is dried onto the complex surface of this ring thereby allowing us to store and propagate our yeast was we brew.
Brewers who brew batch after batch of beer in the same location and always with the same yeast have the luxury of simply inoculating each batch with the wort of the previous batch but what do you do when you brew infrequently or in many different locations? This is where the yeast ring comes in. Because it has a very high surface area with lots of nooks and crannies, yeast can easily be adsorbed onto the surface of this wreathlike structure in a very thin layer making drying easy. This allows the brewer to safely store their yeast in much the same way modern homebrewers and bakers store lyophilized yeast.
These are actually very pretty structures and most people hung their yeast rings in the open to dry. The yeast ring is very likely the origin of the Christmas wreath as brewers would hang these out on their doors to advertise that a successful batch of beer had been brewed.
For those of you who want to try your hand at making and using one of these devices, I have included my instructions here.