Olive oil can indicate a harvest date in addition to a best-before date. What's the difference and how should you use this information?
You've heard it before. Olive oils and wines are similar in how they can be appreciated for their different flavors, geographic origins, varieties, and how they are paired with foods. But there is one crucial difference. Wines can last for many years and generally get better with age. This is not the case with olive oils. The flavors of an extra virgin olive oil will soften over time. If you're a fan of full-bodied oils, yesterday an olive oil was always better for you.
So what do you need to know when choosing an oil? Take into account any information on the bottle regarding harvest date and best-before date.
The harvest date is when the olives were picked from the trees.
The olive oil best before date (or best before date or best before date etc.) is a calculation by the producer/bottler of the olive oil of how long the olive oil can be kept under good storage conditions from the date of bottling.
A harvest date on a label can be important information for olive oil companies and consumers. However, the lack of a harvest date does not indicate poor quality. A company may choose not to include a harvest date on the label for a number of legitimate reasons.
For example, if a product made in October is still on the shelf a year later in November, a consumer may think the oil is too old and opt for something else - although the oil may still have another year of good quality left over . (Indeed, a retailer might be reluctant to buy new product from this company if oil from the previous harvest is still on the shelf.)
Another reason may be that the manufacturer has packaged oils with different harvest dates, which can mean different months and/or even years, since the harvest in a given location can last for a few months and occurs at different times of the year in different hemispheres. With such olive oils—which are obviously not “estate produced” and include the more economical everyday extra virgin olive oils you find in the supermarket—reporting multiple harvest dates can be complicated and confusing.
So while the harvest date can be relevant, the “best before” date is always the crucial piece of information consumers need to know when purchasing an olive oil. Here, to protect consumers, manufacturers must make their best efforts to estimate the shelf life of the oil at the time of bottling. This means that variables such as harvest date(s), storage conditions prior to bottling, the physico-chemical properties of the oil, the opacity of the packaging and the anticipated shipping/storage need to be considered prior to consumer purchase.
Unfortunately, while methods of estimating shelf life are getting better, they're not perfect. As a general rule, and in accordance with International Olive Council standards and the requirements of the NAOOA labeling guide, the "Best before date" should be no more than 2 years from the date of bottling. In many cases, however, the MHD should be lower.
Regardless of the harvest or best before date, it is also important to know that once you open the oil bottle, all bets are off and you should aim to use the bottle within 2-3 months.