Hi Stanley, 

Terracotta and clay cooking vessels and utensils have been used for cooking for thousands of years, and some cooks love their unique cooking properties in preparing dishes like tagines and biryanis. However, there are some food safety considerations you need to consider before using them at home. Chemical leaching, bacterial growth, flavor transfer in porous pots, and physical hazards from pots breaking are all potential concerns if the wrong pots are chosen or used improperly.

To avoid some of these problems, you can take these steps.

First, choose only items that were manufactured for use in food preparation. It may sound obvious, but terracotta garden pots or decorative items not designed for food contact should never be used in food preparation. Not only are these items more likely to leach harmful chemicals, they are also more likely to break when heated.

Also, look for cookware or serving ware that is labeled as "lead free." Lead is often used in pottery glazes to enhance color and glaze bonding, and depending on the type of glazing process used there can be a risk of lead leaching into your foods. This risk is increased if you're cooking or serving acidic foods that can draw out contaminants. Your best defense here is buying your pottery from a reputable source that certifies it as lead free. If you already have glazed pottery items you'd like to use in the kitchen, but you're not sure about their safety, you can buy lead-testing swabs at most hardware stores that are highly accurate. 

For unglazed, porous pots, some special considerations apply. Keep in mind that these pots are more likely to hold on to aromas and flavors even after washing. This can be a desirable quality if they are used for preparing similar dishes time after time, but it can also be a downside if you need a more versatile pot for cooking different foods. Unglazed pots also benefit from a seasoning process, which usually involves a long soaking period followed by an oiling and heating step. Follow instructions from the manufacturer.

Lastly, there does not appear to be a clear consensus on the question of bacterial growth in unglazed pots and utensils. Most manufacturers advise against using detergents to clean this material, due to its tendency to hang on to aromas and flavors. But without soap, it can be difficult to lean the pots as thoroughly. If you do want to use unglazed pots, you can minimize risk by thoroughly washing and scrubbing with a clean cloth to remove all food particles before drying completely between uses.  

Thanks for using Ask Extension!

Jared