Corto Bag-in-Box olive oil has a lower carbon footprint and lasts longer too.
Treehugger usually promotes plastic-free living and zero waste, so I had some initial doubts when pitched that olive oil that comes in "bag-in-a-box" packaging had "60% to 90% lower impact on the environment when compared to single-use glass bottles."
The Corto olive oil is from California and is of high quality. The company explains why they go bag-in-box.
"Corto harvests perfectly fresh olives in the Fall just as the fruit turns from green to violet and antioxidants are at their peak. After being picked, the fruit is rushed to Corto’s onsite mill and cold-extracted within hours of harvest where it is stored in a climate-controlled cellar until a customer order is processed. Only then is the oil packaged directly from the cellar into Corto’s FlavorLock boxes, further ensuring freshness and minimizing exposure to the harmful effects of light, heat, and air."
Researchers at the University of Ioannina found bag-in-box packaging did keep olive oil fresher longer than the traditional steel containers but did not compare it to glass bottles and did not look at the environmental benefits.2 A few years ago, we looked at the benefits of bag-in-box wine and concluded:
"From an environmental point of view, bag-in-box wine is almost a no-brainer. As we noted in TreeHugger almost a decade ago, it uses far less packaging, takes up far less space, and costs far less to ship with far less of a carbon footprint. It often costs less, and the fancy multi-layered plastic bag shrinks as the wine is poured, so it stays fresh for weeks. Other than refilling your bottles like they do in France, there's probably nothing greener."
But that was before we were as concerned about embodied carbon and carbon emissions and before we learned that Category 7 plastics are almost never recycled. These bags are a sophisticated material, "made of a "co-extruded ethylene vinyl alcohol (EVOH) technology -- a five-layer co-extrusion with EVOH sandwiched between two layers of polypropylene." Nobody is recycling that. Some people might use them as sandwich bags, but most are going to end up in landfills.
So in these times, when we worry about every gram of carbon dioxide emissions that count against the budget we have to keep under to hold global heating below 2.7 degrees Fahrenheit (1.5 degrees Celsius), can we still consider bag-in-box olive packaging to be greener than recyclable bottles? Corto pointed us to a 2020 study, "Comparative life cycle assessment of alternative systems for wine packaging in Italy," which did full life-cycle analyses comparing bag-in-box, aseptic carton (Tetra-Pak), PET bottle, single-use glass, and refillable glass in the Italian market. It's not olive oil and it is not in North America, but the results are surprising and illuminating.
Authors Carmen Ferrara and Giovanni De Feo tallied up everything: the manufacture of the packaging, the packing onto pallets and secondary packagings, such as cardboard boxes for the wine, stretch film on pallets, transportation, and the final disposal of the packaging.
The surprising result is that single-use glass bottles came out the worst, by far, in every category, and in particular, with its global warming potential (GWP). There is a lot of material in each bottle, so it takes a lot of energy to make them, and a lot of fuel to ship them. And while glass is recycled at a high rate, it is usually downcycled and ends up in insulation or roadbeds rather than bottles.
Because of their weight and the inefficiency of packaging, the impact of the single-use glass increases with the distance traveled. One might think that refillable glass (something that happens in France and Italy) would be best, but it comes close to bag-in-box only if it travels less than 93 miles (150 km). The study authors conclude:
"The bag-in-box is the preferable alternative, followed by the aseptic cartons that had only slightly worse environmental performances. Compared to single use glass bottles, the impacts of bag-in-box were from 60% to 90% lower. The greater sustainability of bag-in-box and aseptic cartons is due to the lower packaging weight relative incidence and the greater palletizing efficiency, which means less secondary and tertiary packaging to be produced and transported. The refillable glass bottles, although allowed an impact reduction compared to the single use glass bottle, turned out to be a worse packaging alternative than bag-in-box and aseptic cartons for all the impact categories considered. This occurs because of the high environmental burdens of wine distribution phase and secondary-tertiary packaging production phase that were the same for refillable glass bottles and single use glass bottles."
It is likely that the same conclusion can be applied to olive oil shipped from California. The big 3-liter box is a lot lighter than the equivalent in glass, takes up less space in shipping, and because there is never any air in the container, it stays fresh much longer, which you kind of need when you are buying olive oil in such large quantities—it is going to take a while to go through .8 of a gallon and this stuff is too nice to use in my hair.
It was counterintuitive with wine in a box, and it is with olive oil too, but the evidence is pretty conclusive that unless you live close to an olive grove or a "refillery" where you can fill up your own container, this big box of olive oil is going to have a lower carbon footprint than a bunch of glass bottles. I must confess that the Corto oil is pretty yummy too.