The procedure:

1. Put 25g of each size coffee grounds in three beakers (total of 3 samples for each size)
2. Add hexane to each beaker until the coffee grounds are completely submerged then cover the beaker with aluminium foil
3. Let the beakers sit for 3 days, stirring twice a day.
4. Put coffee filters over a new beaker and pour the contents of a sample beaker through the coffee filter
5. repeat step four with all the other samples
6. remove the coffee filter from the beakers and let the beakers sit until the hexane evaporates, then record the mass of the oil that is in the beakers

Along with this, I also used an additional experiment where the coffee beans were homogenized with hexane to further reduce the size of coffee grounds in some samples.

Hexane extracts oil from different compounds because both oil and hexane are non-polar molecules, and bind together.

To measure the particle size I used an optical microscope.