Persian Berries: Part III

Another year, another buckthorn berry harvest.

The 2013 crop was late (hence a New Year posting), but it seems to have been particularly good. I wasn't able to collect it myself, but thanks to the generosity and hard work of Cheryl Porter, Bob Proctor, and Vincent Daniels, I had a decent amount of juicy berries and the chance to experiment again.

This year I worked from a 14th century Netherlandish recipe. It's pretty relaxed about quantities, but specific regarding the method.

First, the berries are crushed and bruised in a bowl before being placed in a muslin square and squeezed to extract the dark viscous juice. This took a bit of elbow grease, and a strong piece of muslin. Next I added the water, and then briskly boiled the mixture on the hob to reduce it a bit. I stirred in a small amount of alum and in the absence of an ox bladder decanted the mixture into a glass jar to cool and evaporate further.

I painted the colour out at each stage. The raw dark berry juice first appears as a vivid purple. Once cooked with the addition of alum it is still a rich purple colour, but now it morphs to green when painted out with water. Finally the colour dries and settles as the bright sap green colour seen on the page of medieval manuscripts. It is this colour which was so desirable that it was harvested and stored for use after the Autumn. It is an incredible transformation.

(Left) Painting out the prepared sap green, at first purple, then bright green once water is added. (Right) Raw juice without cooking or alum, and then once prepared and allowed to dry.