Overview
The Cooking Oil Tester (TPM) works with the common edible frying oils and fats used for deep-frying in most kitchens. That includes vegetable frying oils such as canola, sunflower, soybean, and blends, as well as animal fats used for frying. Whatever you fry in, the tester gives you a TPM reading so you can judge when the oil needs changing.
How It Works
The tester measures the polar compounds that build up as any frying oil breaks down, so it works across different oil types. Because oils differ, the exact reading can vary a little from one oil to another, and that is normal. The state of the oil matters too: oils that are solid or semi-solid when cool will not read correctly until they are fully melted and warm.
Key Things to Know
Oils that are solid at room temperature, such as palm, coconut, or lard, must be fully melted and above 40°C before you test them.
Fresh oil does not read exactly zero — a small TPM value on new oil is normal.
Readings can vary slightly between different oils.
Always measure within the 40–200°C range (see How to take an accurate TPM reading with the Cooking Oil Tester).