Batch Roasting & Milling
Our small-batch methods, step-by-step
1. Seeds
Seeds arrive at our production kitchen in large sacks, which have already been cleaned and dried by the farmer.
2. Seed Roasting
Just like chocolate or coffee beans, seeds are loaded into steel roasters, similar to coffee roasters, to modify seed texture and add flavor. The length and temperature of the roasting steps varies depending on the seed type.
3. Seed Pressing and Milling
Seeds are removed from the roaster and run through expeller presses. The presses apply mechanical pressure to press out the oil.
4. Oil Filtering
Oil from the expeller press is allowed to rest for a brief period, to allow gravity to gently settle out particulates, and then the oil is lightly filtered to remove seed particles that may remain suspended in the oil. Filtering helps to increase the smoke point of oil, as the particulates in oil cause oil to smoke at lower temperatures.
5. Oil Bottling
Oils are bottled the same day as filtering, so oils go from seed to bottle in a matter of several days.
6. Reserving Seed Presscake
Seed that emerges from the expeller press after the oil is removed is called “presscake” and is reserved for seed flours. The presscake is high in protein and nutrients from the seed hulls.
7. Milling Seedcake Powder
Presscake is milled into a fine powder to be sold as varietal protein powders – pumpkin, butternut, and flax varieties. Sunflower presscake is reserved for animal feed.
Extracting oils from seeds
There are three main ways to extract oils from the seeds: cold pressed, expeller pressed, and solvent extraction. The first two involve a machine that applies pressure to extract oil from the seed. The last one requires immersing seeds in a chemical brew to extract as much as the oil from the seed as possible.
How oil is extracted does matter–for taste, product quality, and environmental health. You may have noticed the different oil options that are available to you on the shelves of your supermarket. Canola oil, for example, might say, “expeller pressed” or “cold pressed” on the bottle. Or it might just say “canola oil.”
Solvent extraction is the method used for most mass-produced conventional cooking oils, like canola, corn, and other vegetable oils. This method uses chemical solvents like hexane to extract oils from the seed. These oils are relatively inexpensive to produce, but the harsh refining process can leave chemical residues in the finished oil and impair flavor.
Expeller pressed means that oils are extracted using a chemical-free, mechanical process. The harder the nut or the seed, the more pressure that needs to be applied to extract the oil. This pressure results in more friction and higher heat.
Strictly defined, cold pressed–the method used for delicate fruit like olives–means that the pressing temperature is kept below 122 F. While many expeller pressed oils use the description “cold-pressed,” this is often used loosely and there is no regulatory standard. We prefer not use the term “cold pressed” for our oils, since the mechanical friction of the press does add some heat (reaching temperatures of approximately 140F), but these temperatures are low enough that the taste, nutrients and overall quality of the oil are retained.
