Rapeseed Oil or more correctly “canola oil” (abbreviation of Canadian oil) being its the low erucic acid variety of rapeseed first produced in the 1970’s. Before which all rapeseed varieties were high acid so not fit for human consumption.
- From a culinary perspective the cold pressed oil is useful because it has a higher smoking-point than olive oil & is high in omega-3, the fatty acid found in oily fish, which many diets don’t have enough of – it’s also low in saturated fat (<7%) making it healthier in that aspect than most other vegetable oils..
- It fries well without smoking and produces a pleasant nutty aroma.
- It’s a local food: I can walk to buy it from PJ Meads farm shop or buy Duchess Oil (also local) on Big Barn.
So I know it’s healthy, it’s good in the kitchen & it’s local – but is it low in carbon……?
After much digging around we found some Ecoinvent numbers for oilseed rape oil (&others) to compare against the olive oil numbers we already looked at from Aldi (Australia) – so just a few assumptions……
Then with the guidance of many (thanks) we checked the oilseed rape numbers & agree with the Ecoinvent guide of 2.72 CO2e/kg at the mill-gate, given typical UK fertiliser inputs, yields & present market prices for winter rape (we came up with a figure of 2.87). The emissions numbers from Switzerland at 1.9 CO2e/kg for bulk oil appears very low given UK inputs & yields.
- First we’ve extrapolated the impact assessments of each oil type, providing a best estimate of “factory-gate or farm-gate” GHG emissions (CO2e/kg).
- Second estimated the GHG impacts for a range of Packing + Packaging + Distribution + Retail – producing differing guide scenarios for distance & pack type.
- Thirdly we’ve ranked the various packed oils by their impacts
Overall the estimates made indicate:Reference: sources:
– Ecoinvent: via – Energy Centre of EPFL (2011) Roundtable on Sustainable Biofuels GHG Calculation Methodology – RSB reference code: RSB-STD-01-003-01 (Version 2.0)
– Estimates from ALDI Australia graphs via – http://www.aldi.com.au/au/html/service/15854.htm (farming + milling + refining)
Soya (bean) oil is both best & worst impact wise – most likely owing to deforestation of Brazilian product over that of America.
European olive oil appears to have the lowest impacts, mostly I assume because it is produced on a low input & tillage system – even the Australian olive oil with higher agricultural inputs & significant shipping would still come in around 2.7-3.4 CO2e/kg – so still towards the top-end of the table.
As the Rapeseed oil numbers are based on a standard UK production system it would be interesting to know what the yields & inputs are for alternative systems – would this reduce the impacts by any great extent?
Food miles & weight of packaging make a significant difference – that said agriculture inputs are still the major differentiator.
- Always buy oils in bulk cans – not small bottles
- Given a choice think local as in European when sourcing oil
- Start asking questions on what a low impact rapeseed growing system may look like
- Avoid products grown in a way that results in any kind of deforestation
- This is only looking at carbon – it’s only part of the debate (all be it a big part) & there are obviously other advantages to buying local rapeseed oil: resilience within the UK food system being important as are economic & culinary considerations.
- Should we consider rapeseed oil as a butter replacement?
So it’s healthy, good for cooking, not overly expensive & local, but it is higher than most alternatives as regards to carbon impacts – that’s unless you rip up a few forests to produce them.