What cooking technique is most commonly used to soften vegetables before freezing or cooking?

Blanching is the cooking technique commonly used to soften vegetables before freezing or cooking. This method involves briefly boiling the vegetables for a short period and then quickly immersing them in ice water to halt the cooking process. The purpose of blanching is twofold: it helps in softening the vegetables, making them easier to digest and enhancing their texture during subsequent preparation, and it preserves color, flavor, and nutritional value.

This technique is particularly effective for vegetables that will be frozen, as it helps to deactivate enzymes that could otherwise lead to deterioration in quality over time. By stopping the cooking process shortly after blanching, the vegetables maintain their crispness and vibrant colors when cooked later.

The other cooking methods, while useful in different contexts, do not serve the specific purpose of softening vegetables for freezing or preparatory measures for later cooking. Roasting and baking are dry heat methods that typically result in caramelization and browning, imparting flavors rather than softening, while steaming is primarily used to cook vegetables thoroughly rather than to prepare them for freezing or storage.