I should say my view of this is, environmental conditions (medium and temp) will change the outcome because the fatty acids have changed. I was thinking in terms of the huge variations in the oils used in soap recipes, and even the slight differences in the temperatures when "cooking" it. However, even the genetics of different olive trees would have some impact -- in my mind anyway.
This shows the fatty acid variation in mid-oleic sunflower oil based on location (soil and weather). The seed in question is specially bred to have less linoleic and more oleic fatty acids in its oil. There are three different types of sunflower oil on the market that produce distinctly different results in soap. Plus, as you can see, each of those has its own variations depending on growing conditions.