A lot of companies, particularly in the Middle East, will use industrial machines because they can press more seeds in less time, thus producing more oil. When the seeds are pressed, they end up looking like shiny, flat pieces of plastic. Because so many seeds are pressed at once, many of them still contain oil after the pressing process is finished. They exit the press still wet, and then the companies put them back into the press for a second extraction.
In a way, this makes sense. These are big companies who are looking to supply big markets and need to squeeze as much out of their product as possible to make up volume.
The problem is that the quality diminishes during this second press. It’s not as clean, and the texture and flavor are altered.
In a single press process, the black seeds are spread out in the press in an even layer for maximum extraction. They’re minimally processed in this way to produce a better, cleaner oil