Oil made with ripe olives will offer more health benefits than that made with unripe olives, but the taste and smoking point shouldn’t differ too much. Also note that unripe olives produce green-tinted oil and ripe olives produce gold-tinted oil. [1] X Research source
During this time, you should also sort through the olives and pick out any leaves, twigs, stones, or other debris mixed in with the fruit. These elements can ruin both the oil and the equipment used to produce it. After rinsing the olives, allow the excess water to drain and pat the olives dry using clean paper towels. The olives do not need to be perfectly dry since any water will eventually separate from the oil, but they should at least be mostly dry, especially if you don’t plan to process them right away.
If you do need to wait before making the olive oil, transfer the olives into an open plastic or glass container and refrigerate them as needed. Pick through stored olives before use and discard any that appear rotted, shriveled, or unusually soft.
For homemade olive oil prepared in your kitchen, it’s best to use a bowl or similar dish with sides rather than something completely flat. While the first round of grinding won’t produce much liquid, using a bowl will allow you to collect any liquid that does come out more readily than a flat board or stone would.
A standard meat tenderizer should work well for this step. Metal and plastic versions are advised, however, since wooden mallets may absorb some of the liquid. Note that you can use either face of the mallet for crushing the olives. Consider removing the pits while you work. Since the pits are relatively fragile, you might be able to crush them into the olive paste. Doing so won’t have a negative impact on your olive oil, but stray bits of seed can damage some of the electric tools you’ll need later in the process, so removal is advised. When ready, the olives should be thoroughly crushed, and the mash should have a slightly shiny coating over its surface. This sheen is the oil. The crushing process breaks apart the flesh of the olives, thereby releasing the oil contained within its cells.
While you can technically keep the olive mush in its current bowl, the next part of the process can get extremely messy, and using a glass or dish will taller sides may help reduce some of the inevitable splatter. Alternatively, you can spoon the paste into a durable, high-speed blender. Fill no more than one-third to one-half of the blender.
You only need enough water to help facilitate the upcoming blending process; do not add enough water to completely cover the olives. The water should be hot but not boiling; the extra heat should help release more oil from the paste. Ideally, the water should be filtered or distilled before use since using unfiltered tap water may introduce impurities into the final product. Note that the water you add will separate from the oil later.
Continue the process for at least 5 minutes. Blending the paste for longer intervals should release more oil from the olives, but it also increases the amount of oxidation that occurs, which may result in a shortened shelf life. [3] X Research source Use a relatively high-powered blender if you didn’t remove the seeds while mashing the paste; otherwise, bits of seed can ruin the blades. If you did remove the pits, however, a standard-power blender should suffice. You can also use a standing blender for this part of the process, but you’ll need to pause and check the progress every minute or so. During professional extraction, this part of the process is known as “malaxing,” and it encourages the smaller beads of oil to combine into larger beads.
Try to stir the olive paste using circular rotations. The force of each rotation should help draw more oil out of the solid “pomace,” or pulp. This step is also considered part of the malaxing process, but instead of using high speed to separate the oil, you’re relying on the direction of the force to separate out the various components.
At the end of this waiting period, it should be even easier to see beads of oil along the surface of the olive paste.
Fine mesh strainers are optimal for this project, but the cheesecloth should sufficiently trap any solids even if you need to use a wider-gap plastic colander instead. If you don’t have cheesecloth, consider using large sheets of filter paper or clean (i. e. never previously used) painters’ straining bags.
Note that the cheesecloth should completely cover the entire batch of olive paste. If it isn’t large enough, you should consider separating the paste into even smaller batches.
If you’re concerned about how sanitary the weight is, you can wrap it in plastic wrap before placing it on top of the bundle. Alternatively, you can place a smaller bowl inside the strainer and on top of the olive bundle. Fill this smaller bowl with dry beans or similarly heavy material to apply constant pressure on the bundle.
Every 5 to 10 minutes, gently yet firmly press down on the bundle using your hands to help the extraction process. When you’re ready to move on, the bowl should contain a decent puddle of liquid and the olive solids inside the cheesecloth should look relatively dry. Note that you can discard these solids at the end of the draining process.
Due to the difference in densities, the oil should naturally separate off into its own distinct layer, and that layer of oil should rise to the top of the bowl. It may take a little practice before you can draw off only the oil without also collecting some water or juice. Inspect the body of the syringe immediately after collecting the oil; if there are separate layers within the utensil, expel the water and leave only the top oil layer.
Glass bottles are ideal, and tinted bottles are even better since the tint should help protect the oil from the harmful effects of strong light. If necessary, however, you may use a plastic container. Note that any bottle you use should be thoroughly cleaned with hot water and dish soap, rinsed well, and dried before you pour the oil inside.
The exact material shouldn’t matter too much as long as you can create a tight seal around the mouth of the bottle. Carefully wipe away any oil from the mouth and sides of the bottle during this step, as well. Dab away small spots with a dry paper towel; wipe away larger splashes using a soapy dish cloth, followed by a clean damp cloth, and finished with a dry towel.
Homemade olive oil won’t have the same shelf life as commercially prepared oil, so you should use it within 2 to 4 months for the best level of quality.
