PGB Kitchen Supplies

Use of Earthen Clay Cookware in the Contemporary Kitchen

Earthen clay pots have been around since time immemorial. Early civilizations took advantage of their porous nature, which stores steam and other natural vapors, making then well suited to slow cooking where even, gradual distribution of heat is of paramount importance, to efficient water storage vessels in which those same pores lend themselves to storage of pure, clean water at cool temperatures over long periods of time.

To the lay person, the term clay commonly refers to fine-grained, earthy materials which acquire plasticity upon becoming wet. Clays’ chemical compositions are hydrous aluminum silicates which usually contain minor amounts of impurities such as potassium, sodium, calcium, magnesium, or iron. Geologically, a precise definition of clay has been elusive as the term sometimes is used loosely, and erroneously, interchangeably with the term shale, which technically refers to clays which contain decomposed and usually fossilized organic components. 

Clays can be divided into two classes: clays found at the primary location of their formation and clays which have been transported by natural forces such as erosion, water or wind and deposited in a secondary location. The secondary process is characterized by chemical decomposition of rocks which contain silica and alumina, rock solutions containing a variety of often insoluble metallic impurities and disintegration and solution of shales. The three basic categories of clays are illite, kaolinite and montmorillonite.

Due to their primary formation mechanism, clays and shales most frequently are found in sedimentary depositional environments such as alluvial river valleys and oceanic turbidites close to the mouths of ancient and current rivers and large streams. Due to their profoundly different impacts on the formation, storage and flow of fluids, gaseous, liquid and highly viscous fluids to highly plastic “pseudo” solids in hydrocarbon bearing formations, petrophysically shales are classified as being either structural (as in externally particulate), dispersed (internally distributed within porous rock types) or laminated (layered between clastic silica or carbonate layers).

Our concern for the purpose of this piece is with pure, natural, sometimes referred to as primary clays. Our principal motivation is the known health hazard created by the introduction of certain impurities, particularly those of the metals class, into the food chain; a secondary motivation is the impact some of these impurities can have on an otherwise pure clay vessel’s structural integrity.Primary clay pots must be seasoned before their first use and thereafter heated slowly and evenly. They cannot safely be placed directly upon a preheated stove top or into a preheated oven. They are best suited to slow cooking, where their purity and the natural vapors and any added seasoning or spices which are trapped within their pores act to tenderize and enrich the flavors of the food. In an effort to extend the functionality of clay pots to recipes calling for high heating, such as braising or sautéing, ceramic material and enamel glazes often are applied at very high temperatures to the surface areas of most commercially available clay pots. But these supplemental treatments carry a price, they invariably introduce undesirable impurities into the pots. 

The belief that the hazardous byproducts of toxic minerals which can result from use of cast iron, aluminum, stainless steel and copper clad cookware or from nonstick coated cookware are relatively harmless is not necessarily validated. Enzymes in our bodies can become altered with toxic rather than health inducing components. Metals are reactive while foods are organic and mostly alkaline; under the catalyst of heat the metal ions, chemicals and oxides from glazed, ceramic, metallic or artificially coated cookware react with and leach into the food it contains.

Primary clay, on the other hand, is inert and natural pots composed of primary clay do not introduce in and of themselves any foreign substance, harmful or otherwise, into their contents. Its primary agent  of heat transfer is not by conduction or convection, rather it is via photon transmitted electromagnetic radiation in the far infrared end of the visible spectrum. 

One of the best, and ironically most affordable, producers of primary clay cookware is Miriam’s Earthenware Cookware (MEC™), located in Massachusetts. MEC concentrates solely on the production high quality, hand crafted to exacting standards, pure primary sourced clay  cookware. MEC’s production begins with the careful selection of primary clay from the few commercial sources of such material within the US. Each batch of clay then is submitted to certified laboratory testing against rigorous standards of purity. Any batch that doesn’t match doesn’t catch.

The pots are thrown by local artisans until they meet demanding standards of perfection. Lids are spun and custom fitted. After these steps, they are fired by local craftsmen under precisely controlled time and temperature profiles. Finally, they are inspected closely for the slightest imperfections. Any product which falls short of MEC’s show window standards but is eminently presentable and serviceable is consigned to MEC’s reduced price slight irregularity inventory.

The net result is ready availability of the benefits of healthy gourmet cooking with the finest pure earthenware at remarkably affordable prices to the working middle class, be they blue color or white color. The exceptional quality and attention to detail provided by MEC normally would be expected to be found only at the most elite cookware suppliers. To view a sampling and a compete description of their offerings, you can visit PGBKitchenSupplies.com.