The difference in the texture and moisture content of toast made under the grill (broiler) compared to toast made in a toaster is mainly due to the cooking method and the exposure to direct heat.
Cooking method: When using a grill (broiler), the heat source comes from above the food, and the food is placed on a rack or tray below the heat source. In contrast, a toaster heats the bread using heating elements located on the sides of the slots.
Heat exposure: In a grill, the heat from the top can quickly evaporate surface moisture from the bread, causing it to become dryer faster. Additionally, the direct exposure to intense heat from the top can lead to uneven toasting, where the top side may get darker or even burnt before the bottom side is fully toasted.
Airflow: Toasters typically have more controlled airflow within the toasting slots, which helps retain some moisture within the bread while toasting. On the other hand, under the grill, the hot air rises and takes away more moisture, contributing to a drier end result.
Timing and control: Toasters are designed specifically for toasting bread, providing a more consistent toasting experience. They have built-in timers and settings to control the toasting duration, ensuring the bread is toasted to the desired level without becoming overly dry or burnt. Under the grill, it might be more challenging to achieve the same level of precision and control.
That being said, personal preference also plays a role in how people like their toast. Some may prefer the texture and dryness of toast made under the grill, while others prefer the more controlled and slightly moist toast from a toaster. To get the desired texture, it's important to monitor the toasting process carefully, whether using a grill or a toaster, and adjust the cooking time and heat level accordingly.