Rapeseed (Colza) Oil: Ripened, Threshed and Pressed

Colza, or rape, is a cabbage relative whose small seeds give an oil that lit the lamps of France and Belgium. Andrew Ure (1839) notes the seed yields oil only in proportion to its ripeness, so the plants are cut a little early, before the pods shed, and left to finish ripening in heaps before threshing. The pressing is the same as for linseed oil. The picture: a rapeseed (colza) field in flower.

初学者

A day of pressing

说明

Ripen, thresh and winnow

Let the cut plants finish ripening in an airy heap, thresh out the seed, winnow off the chaff and sift it.

此步骤所需材料：

油菜籽3 公斤

所需工具：

簸箕

粗筛

Dry the seed

Spread the seed thinly in the air to dry before pressing (Ure).

所需工具：

晾晒席

Press, settle and decant

Press the dry seed in the screw press, let the oil settle and decant it clear, exactly as for linseed oil. Keep the pressed cake: Ure notes it fattens cattle.