Here a few instructions for caring for your terracotta cazuelas.
They are incredibly versatile and can be used in the oven, in the microwave and even on the hob. If you are going to use them for cooking (as opposed to simply using it as a serving dish), the dishes first need to be “cured”. You need to soak them in water for at least 30 minutes, but ideally several hours or more. This will strengthen the clay so it won't crack once it's heated. Drain and wipe dry. A traditional technique is to also rub the unglazed bottom with a cut clove of garlic (we are not sure how the garlic works, but it certainly is used by many people in practise)
You can also fill the dish with water, and bring to the boil slowly, then let the dish cool down naturally again. This technique has been used since the Middle Ages. It seasons the dish, kills bacteria and hardens the unglazed parts.
While the terracotta can withstand very high and low temperatures, it doesn't accept abrupt changes in temperature. Slow and steady heat changes are best. Don't pour cold liquid into a hot cazuela, for example. It's also not advisable to heat an empty cazuela.
If you have not used the cazuela for an extended period of time, you may need to re-cure it before use.
They are safe to use in the dishwasher, but because the clay is still porous the drying cycle will not completely dry them. Therefore when removed from the dishwasher simply let them air for a few hours before putting them away.
They can also be used in the freezer, but as before, let them reach room temperature naturally.