Olives are the earliest crop known to be cultivated by humans, having been grown and harvested for at least six thousand years.
In local gardens, their familiar grey-green foliage lends an immediate air of classic antiquity. Once very popular, pressing and curing olives at home has become something of a distant memory. However, for the more adventurous foodie that has access to productive trees, it can be a richly rewarding pastime.
Harvesting at the Opportune Time
If you already have a fruiting olive tree or two in your yard then you’ll be happy to know that olive trees are not that picky—they’re easy to grow. If you don’t know what variety your tree is, some trial and error with harvesting and curing might be in order. Olive trees can be purchased in a wide range of sizes and prices, and can be planted year-round.
Unlike many other fruits, the different colours that olives come in are due to the ripeness of the fruit, not the variety. Harvest time depends primarily on the cultivar and the end-use of the olives. If you want a more intense oil, you should harvest your olives when they are still green.
For a more delicate oil, the colour of your olives should be black, but your harvest shouldn’t be overly ripe. For curing, black or green olives are best, but stay away from half-ripe olives. If harvesting for eating, the olives need to be handled with care; handpicking is essential as damaged fruit will usually not survive the curing process.
Curing Table Olives
For edibility, olives are processed, or “cured,” to remove most of the oleuropein, which is found in the leaves and fruit of the tree. Oleuropein is the main antioxidant in olives, but it’s extremely bitter. Curing neutralizes this compound in different ways which make the olives more palatable.
The process involves slicing or cracking handpicked fresh olives to expose the interior of the fruit. The olives are then immersed in water, which is changed once a day for five to eight days, and soaked in finishing brine with vinegar. You can even add flavours of your liking such as rosemary, chillies, or garlic.
Brine curing is another secure method to remove oleuropein. This method involves soaking the olives in a water solution and pickling salt over several months. A fermentation process takes place during brine curing, which alters the flavour profile in distinctive ways.
Get Creative When Making Olive Oil
In addition to curing olives for eating or cooking, they can also be processed at home for their precious oil. Historically, the process relied on large stone grinding wheels drawn by livestock.
Expensive grinders and oil presses may be purchased, but with a streak of “maker” inventiveness and experiments of other inventions posted on YouTube as a guide, the necessary equipment can be rummaged or cobbled together for much less depending on the scale of the operation.
Whether the final product is olives eaten out of hand or drizzled from golden bottles of silky oil, harvesting and processing olives at home is a nutritional, gratifying reconnection with a deep agricultural and culinary history.