What’s on our supermarket shelves? – Cobram Estate Rich and Robust
admin | August 14, 2011Cobram Estate Rich and Robust
Batch: 1039
Purchased: 11/5/2011, Woolworths Shepparton Victoria.
Price: $AUD5.49, $AUD14.64 /L (approx $USD 13.70 /L)
Best by date: 8/2/2013 (so presumably packed in February 2011)
Package: 375ml green glass
Australian extra virgin certified: Yes
Analysed: 15/5/2011
My measure of FFA: 0.39%
My measure of UV232: 1.485
My measure of UV270: 0.125
Tasting notes: Good intensity aroma of banana and dried herbs. Flavour was a little less obvious, but still generous enough for this style. Medium bitterness and a higher level of pepperyness on the finish.
Recommended use: Bruschetta, oily fish such as herring
Comment: Overall a good example of a supermarket robust oil, in that it was more ‘commercial robust’, rather than ‘specialty robust’ – but knowing the producers I’m certain that this is more by design than by chance. The acidity is one of the lowest of supermarket oils reviewed to date, as were the measures of secondary oxidation (UV232) and further oxidation (UV270). So relative to its competitors, a pretty good offering.
The packaging seemed a little outdated, with a standard 375ml half wine bottle format. However, since purchasing this oil I’ve noticed that the producer seems to have focussed more on a more attractive 500ml square amber bottle format. But the label text is still very hard to read.
I think its worth pointing out that the best before dates on Cobram Esate olive oils are based on considerations of rancimat tests and other chemical attributes of the oil such as levels of DAGs (di-acyl-glycerides), UV tests and PPP (pyropheophytin). This is leading edge oil life prediction but for the average Australian producer the good news is that either Modern Olives or AORL can do these tests and give a pretty good estimation of the actual liukely life and therefore best before date for a given oil packed in dark glass.
So no need anymore just to blithely assume 2 years and in fact this is dangerous esp. for oils such as Arbequina that would normally not last 2 years. AORL is also doing the work now to adjust for clear glass although why anyone would want to store a light sensitive product such as olive oil in clear glass in a hi UV environment such as a shop or a kitchen bench ………….
Thanks for your comment Paul. While there are lots of indicators for the oxidative status of any oil, it still eludes me how they can be used to definitively determine a shelf life. It all gets down to the criteria that one uses to assess whether an oil is rancid or not. Unfortunately peoples perception of rancidity varies as does their acceptance of it. Somehow there needs to be an objective criteria that can be applied to determine when an oil is past it, and a solid method to predict when an oil will get there from the current chemistry that can be measured by a laboratory. Happy times.
The Asutralia standard sets limits for UV, PPP and DAG that i think are pretty good indicators of when you would say an oils has ‘had it’. What we should do is get together with oils at various stages of their lives according to these three parameters and see what you think. Then we could communicate this to those using these tests. I know some prodcuers are very happy with the outcomes.
Hello gents,
Richard, you wrote:
Somehow there needs to be an objective criteria that can be applied to determine when an oil is past it, and a solid method to predict when an oil will get there from the current chemistry that can be measured by a laboratory.
It’s now pretty clear that after the first 6 months (during which the rate of DAG isomerization varies significantly with initial FFA), the DAG ratio and PPP change in a pretty predictable ways, unless the oil is truly abused, and it sure seems (from looking at RIRDC studies, the CHOICE study, the UC Davis study, and soem lecture slides from Gertz (any idea why the man won’t PUBLISH??)) that exceeding the Australian DAG and PPP cutoffs strongly predicts failing the organoleptic test in a way that the IOC parameters don’t. It would be nice to have an even more carefully-controlled study with multiple oils with a nice continuum of ages and starting chemistries, but I would think at this point we’d be in a very good position to predict when an oil is going to go bad from the parameters Paul mentions?