The colour of the oil is influenced by the degree
of ripeness of the fruit when pressed, and also
by the cultivar. Usually greener fruit produces
a greener coloured oil. So dont let the colour
of the oil influence your choice to much, although
oil from a riper fruit (a pale golden colour)
generally has a milder flavour.
Virgin extra oil keeps better in the dark, away from the heat and light. Try to buy oil in a dark bottle and away from a source where the oil is stored in a cool place away from direct light.
Supermarkets may be convnient, but the are not
necessarily the best place to shop for extra virgin
Price is not always an indicator of quality. Smart
packaging, especilly smart glass, is expensive
and adds to the price of oil. When you find an
oil to your taste, check to see whether you can
buy it in a plastic container at a reduced price
and bottle it into glass yourself when you get
home. Infact, one of the best reasons for buying
olive oil direct from the farms, is that the price
is often lower than that in the stores.
If you are keen on flavoured olive oils, remember that these oils can no
longer accurately be referred to as "extra virgin",
because foreign elements have been introduced
into the oil. You may need to check the quality
of the oil as well - after all no one makes gluhwein
from good quality wines!