Yes, kheer can be stored for the next day. To prevent excessive thickening, ensure it's cooled completely before refrigeration and add a little milk when reheating.
Kheer, being a rice pudding, tends to thicken upon cooling due to the starch in the rice absorbing more liquid. To minimize this:
Cool Completely: Allow the kheer to cool down to room temperature before transferring it to an airtight container. This prevents condensation inside the container, which can affect the texture.
Proper Storage: Store the kheer in an airtight container in the refrigerator. This helps prevent it from absorbing odors from other foods and also slows down the thickening process.
Reheating: When reheating, add a splash of milk (dairy or non-dairy) to loosen the consistency. Gently heat it on the stovetop over low heat, stirring frequently, or microwave in short intervals, stirring in between, until heated through.
Avoid overcooking the kheer initially. If you cook it for too long, more starch will be released from the rice, leading to a thicker consistency upon cooling. Aim for a slightly thinner consistency than your desired final result when you take it off the heat.