With the arrival of spring, it's the perfect time to clean out even the most forgotten corners of the kitchen. And if there's one discreet intruder that invites itself into our cupboards, it's the rancidity. Forgotten wholemeal flours, walnuts that have been open for months, the bottoms of oil bottles... these are all foods that can lose their quality before you know it. The most reliable weapon for spotting them? Your nose.
The story of a failed scone
During a workshop at the university, a teacher prepared scones with barley flour that she thought was fresh. As they baked, a strange odor emerged. When it came time to taste, the verdict was clear: a pungent, cardboardy taste, typical of rancidity. The students, unfamiliar with the authentic taste of fresh flour, thought it was a "healthy" flavor. This anecdote is a good illustration of how rancidity can go unnoticed, especially when you're used to it.
How do you recognize rancid food?
Rancid food doesn't change its appearance: it may seem perfectly normal. It's the smell and taste that do it. Characteristic notes are reminiscent of wet cardboard, paint, varnish or modeling clay.
This addiction to rancid taste can have several origins:
- The habit Some store-bought chopped nuts are already rancid, but you get used to it.
- Giant formats The longer a product is left on the shelf, the greater the risk of rancidity.
- Fragile oils Mono- and polyunsaturated oils are healthier, but also more sensitive.
- Whole grains Brown rice, wholemeal flours and wholegrain cereals go rancid faster than their refined equivalents.
What to do with rancid food
No miracle: rancid food must be thrown. Rancidity is irreversible, and if you use it in cooking, it will give your dishes an unpleasant taste. As soon as you ask yourself the question "Is this normal?", it's best not to take any chances.
How to prevent rancidity?
Rancidity is caused by the oxidation of fats: air, heat and light accelerate this process. To reduce losses and keep food fresh:
- Buy in small quantities.
- Choose stores with fast-moving inventory.
- Store products in airtight containers.
- Place sensitive foods (flours, nuts, seeds) in the refrigerator or freezer.
- Protect oils from light and heat.
Storage tips to avoid rancidity
🧴 Vegetable oils
Store oils in a cool, dark, well-closed place.
- Olive oil 1 year at room temperature after opening.
- Vegetable oils (canola, sunflower, soybean, safflower, grape seed, peanut) 6 months at room temperature.
- Toasted sesame oil 6 months at room temperature.
- Walnut oils (e.g. walnuts) 3 to 4 months in the refrigerator after opening.
- Linseed oil 4 to 6 weeks in the refrigerator.
For other oils (avocado, argan, pumpkin seed...), respect the "best before" date indicated on the packaging.
🌾 Whole flours
Wholemeal flours go rancid quickly because of the germ and bran.
- Industrial whole wheat flour 6 months in the pantry.
- Stone-ground flours 3 months at room temperature, 6 months in the fridge, 1 year in the freezer.
Always allow flour to temper before use if it has been stored in the refrigerator.
Storage tips to avoid rancidity
🧴 Vegetable oils
Keep all oils away from light and heat, and tightly closed.
- Olive oil 1 year at room temperature after opening
- Vegetable oils (canola, sunflower, soybean, etc.) 6 months at room temperature
- Toasted sesame oil 6 months at room temperature
- Walnut oils (e.g. walnuts) 3-4 months in the refrigerator
- Linseed oil 4 to 6 weeks in the refrigerator
👉 Tip: Check the "best before" date and follow the directions on the label.
🌾 Whole flours
Rich in lipids, they go rancid faster than white flours.
- Industrial whole wheat flour 6 months in the pantry
- Stone-ground flours (integral) 3 months at room temperature
- Visit refrigerator up to 6 months
- Visit freezer up to 1 year
⚠️ Allow the flour to temper before cooking.
🍚 Brown rice
Contains bran and germ: more nutritious but also more unstable.
- 3 months in the pantry
- 6 months in refrigerator
- 1 year in freezer
🥣 Cereal flakes
Good shelf life thanks to light heat treatment.
- Up to 1 year at room temperature (oats, barley, spelt, rye, etc.)
🥜 Nuts and almonds
- Whole nuts 3 to 4 months in the pantry
- Visit refrigerator 1 year
- Visit freezer 2 years
- Chopped or ground nuts : always cold
- Whole unbleached almonds 1 year at room temperature
- Sliced or ground almonds : in the freezer
👍 Can be used straight from the freezer.
🌻 Seeds (sunflower, pumpkin, flax)
- Sunflower/pumpkin, roasted and shelled :
- 3 months in the pantry
- 6 months in refrigerator
- 1 year in freezer
- Raw sunflowers 1 year at room temperature
- Whole flaxseeds 1 year in the pantry
- Ground flaxseed :
- 3 months in the fridge
- 6 months in the freezer
Is it dangerous to eat rancid food?
Eating the occasional rancid food is not toxic, but it is not recommended:
- Oxidation destroys the good fats and some of the vitamins.
- It can cause digestive discomfort.
- In the long term, specialists suspect that regular consumption could contribute to inflammatory diseases, cardiovascular disease and even certain cancers.
In conclusion
Rancid foods sneak into our pantries. Even if they don't seem visibly damaged, their smell and taste are telling. A simple pantry clean-up and a few good preservation habits are all it takes to avoid waste, preserve flavours and protect your health. Trust your nose: when in doubt, throw it out!
