Pecan Oil Extraction Guide

In response to Will's pecan extraction guide, I will write about a much more difficult process: the extraction of pecan oil.

Complete extraction occurs over two stages:
Pressing.
Extraction.

There is no cracking involved; this isn't the petro industry. Plus, the last time I checked, the cost of a cat cracker was approaching 2 billion dollars.

There are two methods to pressing: hot pressing and cold pressing. Unless you're a housewife with a wedge press and infinite amounts of time, you're going to go with hot pressing. C'mon you want be a man don't you?

The heat will affect the oil quality, but let's say we're targeting the massage oil market rather than the cooking oil market. So we'll go for maximum yield. The heat makes the oil less viscous and increases the yield.

First we start feeding our nuts into a screw press. As the press operates, the friction and pressure involved will heat up the seed cake. We pass the effluent oil through a filter and collect the product.

But we can still increase the yield further by the method of solvent extraction. In particular we need a non-polar solvent because washing out oil with water is just silly goosery. Let's use MIBK.

HAHA! Just kidding!

Let's use hexane, because everybody uses hexane for everything. Hexane is a good choice because it's relatively safe, volatile and unreactive. So we wash the seed cake out with hexane. Now we need to separate out the solvent again for recycling and because people don't want to eat/rub themselves with hexane. As much as I like flashing, I can't say that high pressures and temperatures are good for the product. Steam distillation is a much better choice because we can boil off the hexane at a lower temperature than otherwise and is an overall more gentle process.

Once we remove the hexane, we can easily separate the water from the oil because they are immiscible. The product is ready for bottling; for maximum freshness store in a cool dark place.