The practice of adding a few extra seconds to the end of the set cooking time in microwaves is a user-friendly feature designed to avoid potential user frustration and improve the overall cooking experience. This feature is often referred to as "kitchen timer" or "grace time."
There are a few reasons why microwaves include this feature:
Complete cooking: In some cases, the microwave's internal magnetron may take a moment to reach its full power output after the timer starts. By adding a few extra seconds at the end, the microwave ensures that the food is exposed to the maximum cooking power for the entire intended duration, ensuring that it's thoroughly cooked.
Avoiding user intervention: Microwaving food in small increments can be an inconvenience for users who have to stop and restart the microwave multiple times to achieve the desired cooking results. The grace time helps minimize this need for manual intervention by providing a little extra cooking time to compensate for any slight discrepancies or variations in microwave performance.
Preventing undercooking: Sometimes, users might interrupt the cooking process a few seconds before the timer ends because they believe the food is sufficiently heated. The grace time helps prevent premature removal of the food, reducing the chances of undercooking.
Consistency and user experience: By consistently adding a few extra seconds, manufacturers can create a more reliable cooking experience for users across different microwave models. This feature has become somewhat of a standard in microwave design.
While the grace time can be helpful in ensuring thorough cooking, it's still essential for users to pay attention to their specific microwave's cooking performance and adjust the cooking times as needed for different types of food. Microwaves can vary in power output and efficiency, so it's always a good idea to follow any specific instructions provided by the manufacturer for optimal cooking results.