For Consumers
What you fry in is what you serve.
You check sourcing. You read labels. You ask if the chicken is antibiotic-free. But nobody asks about the oil it's fried in — and right now, there's no way to know if it was tested today or last tested never.
Your food is only as good as the oil it's cooked in.
Why the oil matters
Frying oil degrades every time food enters the fryer. Water from the food triggers hydrolysis. Oxygen in the air drives oxidation. Over time, these reactions produce compounds called total polar materials (TPM) — a mix of free fatty acids, aldehydes, and polymers that affect taste, texture, and health outcomes.
At least five European countries mandate that restaurants discard frying oil when TPM exceeds 25–27%.[1] The United States has no such requirement. Most American restaurants have never measured their frying oil TPM. The decision to change oil is typically based on a fixed schedule or visual appearance — neither of which reliably predicts actual oil quality.
Grootveld et al. (2017) demonstrated that PUFA-rich oils at frying temperatures generate volatile aldehydes — including 4-hydroxynonenal and malondialdehyde — at levels that may exceed WHO tolerable daily intake thresholds. The choice of frying oil and its state of degradation directly affects what diners ingest.
Grootveld et al. (2017), Lipids in Health and Disease, 16(1), 214.
Degraded oil also changes the food itself. Saguy & Dana (2003) showed that food fried in degraded oil absorbs 20–40% more fat than food fried in properly managed oil.[2] The texture gets softer and greasier. Off-flavors from oxidation products — rancid, sour, sometimes fishy — transfer to the food. Color darkens prematurely.
None of this is visible to the diner. You cannot tell by looking at a plate of fries whether the oil was fresh or overdue for replacement. That information asymmetry is the problem the WIYO! seal solves.
What the WIYO! seal tells you
The kitchen filters its oil daily — at minimum
Frying oil is tested with a TPM meter, not guessed at
Oil is discarded at 25% TPM — the standard used in Belgium, Spain, France, and the Netherlands
At least one staff member is trained in oil chemistry and degradation science (Silver+)
The oil type is disclosed to diners (Gold)
Records are kept and available for inspection
Ask your restaurant
You don't need a chemistry degree. Three questions change the conversation:
“What oil do you fry in?”
The type of oil matters. Fruit oils like palm and high oleic varieties (sunflower, canola) produce far fewer degradation byproducts than conventional PUFA-rich seed oils (corn, soybean, grapeseed) at the same temperature.
“How often do you test it?”
If the answer is "we don't" or "we change it every X days," there's no data behind the decision. NCOMA-certified kitchens test TPM at minimum daily.
“Are you NCOMA certified?”
The WIYO! seal means the kitchen has been independently inspected and meets a published standard. No seal, no standard.
Find certified restaurants
Search the NCOMA directory to find restaurants near you that manage their oil to a real standard.