July 19, 2012
Several plants with fatty seeds has been grown in Scandinavia prior to the medieval period and it is possible that seeds from flax, hemp, rapeseed and gold-of-pleasure (Camellina sativa) as well as hazelnuts could have been used for oil which in turn could have been used both for cooking and for various crafts. From historical sources we know that rapeseed oil was in use in Holland at least in the early 16th century and that recipes for making walnut oil and almond oil can be found in danish cookbook from the 13th century. In Eketorp a site that was in use both during the late Iron Age and through the medieval period a small “cake” consisting of seeds from both flax and gold-of-pleasure was found and later analysed.
However, less is known of how the oil was actually manufactured during the Viking Age. In this experiment I aim to try to make flaxseed oil using the methods and material that may have been available at the time.
Method I: This one is inspired from a 13th century recipe for walnut oil. In the original recipe the nuts are placed in a heated mortar and then the oil is wrought through a cloth. As stone or metal mortars are lacking, and I can not get hold of a soapstone vessel, I intend to crush the seeds into a paste with a heated stone on a saddle quern and then wring out the oil through a wollen cloth if available (Woollen cloth rather than linen was used in the flax oil industries as they will absorb less oil, I guess). In order to get a better force in the wringing I would like to fasten one end to the wall/ a tree or something else firm and in the other end use a branch to help me wring it.
Problems: The cloth will still absorb quite a lot of oil, and will I be able to get the oil out of the cloth. Another potential problem lies in the durability of the cloth – will it hold? Finally is ofcourse the question if we will be able to extract any oil at all?
Method II: This one is inspired from later industrial production of flax seed oil. First I’ll bruise and crack the seeds on the saddle quern and then pack them into a bundle, again in a woollen cloth. The bundle will be put in a mansized wooden mortar.[ Though no finds of them survives, there are some large wooden artefacts that may have been used as pestles.] Repeated beating with the pestle may give the same result as pressing the seeds.
Problem: The main problem with this method is of course if the mortar will absorb most of the oil. In actual use the mortar would probably be saturated from everything that has been pounded in it – to properly simulate a well used mortar I could perhaps try to soak it in some other oil before we start the process.
Method III: Crush & boil. In this trial I’ll first crush the seeds and then pour the paste into boiling water and let them boil with it so that the oil collects on the surface. The the oil is skimmed of or decanted. This method however seem to have no connection with traditional ways of making oil as far as I could find.
Problem: I am not sure that I can achieve that with the available material.
Now oil extraction lies a bit outside my expertise, so any input on making traditional oils or methods of pressing seeds in pre-historic Scandinavia is welcome.