Hippy Fats: Free Fatty Acid Explainedadmin | February 1, 2010
Many extra virgin olive oil producers state the free fatty acidity (FFA) of their oils on the back label. Usually it is in the form of a statement like “Acidity less than 0.2%”. But what does it mean? Is acidity good or bad? Can you taste it?
But first I’ll have to give a bit of Fat 101. The fat molecules which make up olive oil are made up of three smaller parts called fatty acids. The figure below shows what one looks like.
Inside the olive plant cell are little compartments – some contain perfectly formed fat (oil) molecules (like the one shown above) while other compartments contain water and the enzymes that degrade the oil molecules. So, if at any time, these compartments are damaged the enzymes can come in contact with the the oil molecule cleaving off and freeing one or more of the fatty acids.
If the olive is undamaged and disease free then the fat will remain protected, cocooned inside its own compartment. If these good quality olives are crushed immediately after being harvested and are quickly turned into oil, then the oil molecules will only remain in contact with the degrading enzymes for a very short time. Under these circumstances the amount of enzymatic damage that can be done to the oil is minimised, and so the amount of free fatty acids created is very small.
On the other hand, if the olives are damaged either before or during harvest, or (more typically) if the olives are left in piles whereby the olives begin to ferment, then the fat degrading enzymes will have ample opportunity to break off the fatty acid bits of the oil molecules increasing its free fatty acidity.
The free fatty acidity of the oil made from these olives which have been left to sit around for a month before processing would be through the roof! Maybe even as high as 0.8% ….
So in short, the FFA value is a broad indicator of the quality of the olive fruit and how quickly the olives are processed into oil.
Ok, the lower the free fatty acidity of the oil the better. But how low is low? The International Olive Council has set a limit of FFA in extra virgin olive oil of 0.8%. But, frankly this limit is a complete joke. You can totally abuse an olive and still meet this limit. Recent research has shown that even olives that have been left on the ground for 5 months prior to milling have still produced oil under this limit! I guess it allows a lot of poorly made substandard oil to be put on American and Australian supermarket shelves by large European conglomerates, and still be labelled Extra Virgin.
As chief judge of the Australian National Show I’m privileged to have access to the FFA readings of the hundreds of Australian extra virgin olive oils entered into that show. I’ve compiled the results of two shows and these are given below. Note the large percentage of oils which had FFA’s under 0.2% i.e. those less than 4x the IOC limit. So based on this pretty representative sample of what good extra virgin producers are doing in Australia and presumably elsewhere including the US. It would be fair to say to look for extra virgin olive oils with a free fatty acidity of less that 0.2% . For ‘late harvest’ oils an FFA below 0.3% would be a good place to start. Oils of this type need a bit of leeway as they naturally come in a bit higher regardless of what a grower or processor does.
And no you can’t taste the acidity. FFA’s are technically acids, but as far as acids go they are very very weak. So weak that our taste receptors aren’t sensitive enough to detect them.