Can I use a tagine on a glass cooktop, and do I need a heat diffuser?

My name is Tom Wirt, with Clay Coyote Pottery. I'll try to shed some light on the intricacies of clay cooking pots, especially tagines.

You can use any flameware tagine directly on the glass stovetop. This includes, Emile Henry, Le Crueset, and Clay Coyote flameware. These are pots with either a metal base (Le Crueset) , or a type of ceramic called flameware (Emile Henry, Clay Coyote which is formulated and made to take direct heat.

Normal stoneware clay pots and earthenware pots will not do this. Stoneware should never go on a direct heating source, gas, electric or glasstop. It will crack with or without a diffuser.

Earthenware ceramic pots, typically identified by a reddish clay color and some absorbency by the bare clay (typically the bottom), do need a diffuser and should be started over a low heat. They can crack if used over sudden or too high a heat. Remember that these pots were originally used over charcoal fires.

Metal, obviously is fine.

The flameware ceramic pots, are designed for direct heat and are actually especially good on glasstops as the top spreads the heat better than electric or gas. Clay is a insulator, not a conductor. Thus the heat doesn't spread much, but, with a highly liquid food like a tagine, the liquid spreads the heat. Basically a tagine is cooked at a simmer, even though the pot would take the heat. Induction stoves require a metal plate with ceramic cookware to turn the electromagnetic force into heat.

You can find more info on my blog.

It looks like your standard advice is to use a diffuser.

The need for a diffuser when used in conjunction with any electric cook top seems pretty universal across all tangine material types while browsing other manufacturers sites.

Diffusers come in various materials ranging from tin, to steel, to aluminized steel, and cast iron. The Nordic steel diffusers are recommended by not only the Williams Sonoma link (on the page), but also a vendor that sells the Mason Cash tangine.

Exception: Take note that some tangines have a "footed base for heat diffusion." If the one you used on the cast iron has a footed base it is possible that it took so long because you were double dodging the heat.

For the Williams-Sonoma, under the "Use & Care" tab:

• "Safe for use on gas and electric cooktops and outdoor grills; on stovetops use a diffuser."

For the Mason Cash:

• "When using the tagine on a hob, always use a heat diffuser."
• "Suitable for on the hob (with a heat diffuser), in the oven, microwave and to serve"

In general:

• "Heat diffusers are almost always essential if using a Tagine pot of earthenware, clay, ceramic or any material other than metal. Tagines were originally designed as heavy earthenware pots to be used on charcoal braisiers for slow cooking. Even the modern designs with a few noteable exceptions will crack if used on a present day hob and the heat is turned up. Take note of the manufacturers instructions... Also take note of manufacturers instructions regarding electric induction hobs, some Tagines will work if you use an induction hob adapter, others do not reccomend use on induction hobs."

In my researching it seems pretty unanimous despite the merchant, manufacturer, or material that you should be using a diffuser on the stovetop, gas or electric. Whether you "can" get away with not using one because it is "heat resistant", my advice is to not risk exploding ceramic shrapnel in your face.

It sounds like your cooktop might be an induction range. All the tagines I've ever seen were earthenware, so I wouldn't expect them to work at all -- you'd need some sort of metal plate such as a heat diffuser or your skillet to heat up and transfer the heat to the tagine.

There are other kinds of smooth cooktops, but you'd probably know it if you had one that would work with your tagine.

I'm Barbara Wilde, from the webside www.frenchgardening.com, where I've sold clay cookware for about 12 years. I also do about 75% of my own cooking in clay pots from all over thw world, including many tagines. You definitely need a heat diffuser. However, if your cooktop is a glass INDUCTION top, I wouldn't recommend you try using clay pots on it with the adaption clips sold for regular cookware. The only way to do that might be to put the adapter on a steel flame tamer, and put the claypot on top of that.

The instructions for my Jenn-Aire gkass top recommend or require an abdolutely flat bottomed pan. My tagine and others I have seen have an indented bottom. Just an observation.