I always threw the oil cap: a colleague explained to me what he was really doing.

Checking the amount of oil to be used
When it comes to preparing a recipe that only requires a drizzle of oil, it is sometimes difficult to control the amount that flows from the bottle. As a result, we always end up putting in more than it needs to be. But thanks to the plastic tab inside the bottle, below the cap, this problem will be solved very quickly.
Indeed, the small ring makes it possible to partially block the beak of the bottle, and therefore to control more easily, the amount of oil to be poured. Thus, this liquid can be poured without losing a single drop. Pretty practical, right?

However, be careful not to press the tongue too hard so as not to push it inside the bottle. To do this, it is sufficient to press gently and slightly.

The sequel on the next page