We have a fairly broad selection of oilseeds available to us in our area and the better part of the last year was spent researching the uses and comparing the different types of oil extraction equipment, we decided to try a rotary expeller.
There are three types of rotary expellers available, commercial high volume presses, small volume electric countertop presses and the Piteba hand-crank press. We bought the Piteba press with plans to move up to a commercial press when possible.
You can order the Piteba directly from the factory but it can be found in the US if you watch the auction sites. It arrives unassembled and includes clearly written assembly drawings and instructions for expelling oil from several types of seeds . Below are the main pieces of the press.
Along with these parts, there is some mounting hardware and a small oil lamp. Our press did not come with the metal oil lamp clamp that was shown in the photos at the Piteba website. Instead we were provided with 2 rubber bands.
Mechanical assembly is straight forward and simple: insert the screw shaft, attach the crank handle and thread the endcap onto the housing There is a thrust washer at the crank end of the screw-shaft that needs to be well lubricated before use. The oil-lamp must also be assembled and it actually took longer to install the lamp’s wick than it did to assemble the rest of the press.
I’m not sure where or how we’ll be mounting this yet so for this trial run it was just clamped it to a bench. A 2 liter pop bottle was sacrificed for the feed funnel.
We used sunflower seeds for this test and, for best results, the seeds needed to be warm. The oil lamp was lit and the press was pre-heated for a few minutes before starting to run the seeds thru it.
Exactly 2 cups of seeds were put into the feed funnel. It took several cranks to get a good flow of “seed-cake” started and some oil was lost out of the front of the press. Once the cake was fully formed, the oil began to run out of the bottom as it should. There’s definitely a rhythm to it, you want to feed continuously yet get maximum oil flow. It took only a couple minutes to process that amount of seed.
The 2 cups of seeds provided 1/3 cup of oil. There was some sediment in the oil as you can see in the photo. I filtered the oil immediately after this but you could also put a screen over your oil funnel and just let any remaining sediment settle out over time. The seed-cake is supposedly loved by rodents and birds….I don’t know, but it looks like good kindling or compost to me.
I like this press. It does what it claims to do but I do think there’s room for improvement.
- I think the oil lamp mounting method is a safety hazard and will be the first thing that will be changed.
- I’ll be adding a better bearing arrangement on the screw-shaft. I’d like to investigate the possibility of adapting this press to a bike but the current bearing arrangement would never last.
- This press needs to be cleaned immediately after use! I let it cool down before cleaning and was left with a rock-hard mess at the seed-cake outlet. I’d also recommend getting a couple extra 1″ – 1/2″ bell pipe reducers for spares.
Hopefully, we’ll be posting our results with other oilseeds.