When you are first learning how to use an oil press, one of the first unfamiliar tasks that you need to master is seed preparation. Properly cleaning and preparing the seeds is essential for successful using an oil press to produce your own vegetable oil.
While the specifics of the preparation process vary depending on the species of the seeds being used, there are two main steps involved in cleaning that are generally applicable. The first step involves taking off the hulls or seed coats from the seeds. Depending on the type of seed, you may be able to use these hulls for other purposes. For example, soy and sunflower seed coats can be used as an additive for animal feed. Regardless of the type of seed, you can add the removed hulls to your compost bin.
The second step involves the separation of the seeds out from the chaff. You can use a considerable variety of smaller or medium scale methods and devices to aid you in both steps. The available technologies range from a small fanning mill to a spiral separator.
Required conditions of seeds
Seeds must be fully clean. Obviously, stones and large particles of dirt can damage the machinery of the oil press. However, other types of dirt and sediment can also cause problems. Over time, sand can wear down the smaller parts of the press. Chaff remaining with the seeds can interfere with the process by absorbing a portion of the oil. Even small amounts of dust particles can interfere with the machinery of an oil seed press.
Seeds must by dry. In general, most varieties of seeds need to be have a moisture content of 10 percent before being processed in an oil press. Seeds that are too moist can cause the machinery to become clogged. They can also lead to lower yields of oil. A more serious potential problem is the fact that overly moist seeds can become moldy.
Seeds must be warm. If the seeds are within the proper temperature range, they will produce a greater amount of oil with the same amount of effort. This range is between 100 and 160 degrees Fahrenheit. This temperature can be achieved by several means, depending on the amount of seeds being processed. Small amounts can be successfully heated with an oven, double boiler, or solar collector. Larger batches require a heated hopper.