On a one hectar field you are able to harvest around 500 kgs of pumpkin seeds. These seeds must be dried and cleaned. For 1 litre (31,88 fl oz) oil you need around 2.5 kgs of dried seeds.
The dried seeds are crushed and fine milled. Water and a little bit of salt is added to the seed flour. Then everything is dispersed. The water is necessary to hold the flavour and the oil at the following roasting process. This process is done at a low temperature to protect of burning the seed flour.
The roasting brings the typical flavour and makes the oil tasting so fine! After roasting, when the seeds have the typical flavour, the pressing is done with high pressure to gain the oil.
The fresh pressed oil is stored for some days, because some parts of the seed flour have to rest down. Then the oil is bottled or canned at your convenience.