Article originally published in Backwoodsman Magazine (Jan/Feb 2012 edition), and is published here by the same author.
While cooking with hot stones dates back thousands of years, it is still utilized by many today around the world as a primary or secondary means of heating stews, cooking meats, and baking breads. And why not? The amazing capabilities of the stone’s heat retention, its versatile use, and its availability lends itself as a prime choice material for grilling, baking, steaming, boiling, and drying foods.
Dehydrating Foods
In New Jersey, archaeologists have uncovered large, man-made beds of collected river stones. One in particular measured about 25 by 50 feet in size. Some rocks show signs of fires that were made on top of them. The earth below contained posthole stains, suggesting that racks were built above the rock beds. Being that these tend to be located close to rivers and their distributaries, it is theorized that the Native People suspended their fish on the racks above the rocks to dry. The rocks either had fires built on them, or the beds were constructed in full sunlight to catch sun rays and heat the rocks. Either way, the job of the rocks were to continue to give off heat to the food above even after the fires died or the sun went down. This would be helpful in continually drying food when the usual dampness of the night and morning hours crept in. The worse thing to battle while drying fish (or any food) was the natural environmental moisture, so any tool that might have given an edge was well appreciated, and hot stones were that tool. It should be stated that certain foods may have also been dehydrated directly on top of the hot or warm rocks. We know many Native Peoples dehydrated mussels and clams in this fashion to store them for later use.
While this may not seem like a “practical” mode of dehydration for most today, keep in mind that a rock bed under your cooking fire does draw in and release heat. When our cooking fires have to be hot, we line our hearth with stones before we start building the fire. We stop feeding the fire 2 hours before we have to quit cooking, and the hot rocks give off enough heat to “coast” us to the end. And do be careful. We have put our day long fire out, drenching it with buckets of water, only to have it ignite with a little bit of dry grass 3 hours later.
Steam Baking
Famous along the Northeastern coastal areas are the New England clam bakes. Considered a perfect way to steam shellfish, these clambakes not only prove themselves culinary wise but also in practicality. Today a smorgasbord of foods, usually including lobsters, crabs, clams, corn, potatoes, and onions, can all be cooked together in one action without any cooking containers (such as in any other circumstance where many pots and pans, plus stovetops and ovens would be used to accomplish such a varied meal). Accomplished today with or without a pit, a bed of rocks were heated by fires built on them. When the fires died down, seaweed was gathered and generously layered on the hot stones. The food was placed on next, with or without anymore seaweed for moisture and flavor. Today, many use a plastic tarp to cover the mound of food (many use clear purposely to view the food although the moisture may burr details), anchored in at the sides with rocks and logs as the tarp swells with steam. Presumably, before plastic was used, coverings made of the usual materials of the culture (whether Native or colonial) were used and covered with earth to create a more air-tight seal to trap the steam.
Pit Baking
Pit baking can be accomplished by several methods such as surrounding food in hot coals in a pit, or just placing food in the ground, covering it, and placing a fire over it above ground. However another method to pit baking is lining a pit with hot rocks, placing the pot of stew or wrapped cut of meat in and covering it to bake for hours, usually overnight. For the contemporary camper, hot-stone pit baking is a great tool for saving a leftover stew for morning breakfast without keeping the fire going all night long. Cover your stew with a good lid (Dutch ovens would be obviously the top choice for this method), place in the hot stone lined pit and cover with some more hot stones (some use dirt however an annoying threat of accidentally dropping dirt into your food while digging out your pot exists). This is also a great method discourage little food thieves such as raccoons; not to equate death to food but there was a reason many cultures used large piles of rocks on graves to protect them from scavengers. And as always common sense must prevail ‘” never bury your food near your camp in bear territory (or process food near your sleeping location).
Surface Baking
For many, the first thing that comes to mind when speaking about hot-stone baking are the Native women of the American Southwest and Mexico. These bakers famously made corn tortillas on flat, stones and expertly dragged their ash-covered thumbs over the hot surfaces, catching the thin cakes and flipping them, which would have undoubtedly burned a less skilled person. And while stone baking grains may have added ash into the meal, a little bit only added flavoring (only large amounts of ash or “ash lye” was bad to ingest). In fact, certain rocks used and/or certain ashes mixed in made ingredients like Blue Corn flour much more nutrition to consume (in the same way soaking Flint Corn in ash lye made Northeastern Indian hominy more nutritious by adding amino acids). More than those of the desert areas of North America, people all over the Americas and the world did (and still do) bake on hot stone surfaces. The historic ash cakes for example, while the Woodland Indian People baked such in the coals of the fire or on hot stones, the pioneers baked them on the stone slab foundations of their fireplaces, constituting such methods as hot-stone baking as well.
Surface Grilling
While no different in style and method than surface baking, hot rock grilling is just separated here to emphasis the searing of meats, fish, and vegetables. Take the steak out of the cooler and just slap it on a hot stone. It will stick for the first few minutes, but just as it’s ready to flip, it seems to release automatically (a good cook always listens to the food). Best part is, it sears the outside so quick with total surface contact and therefore, unlike a grill surface, it locks the juices in. Like fish? Then throw a trout on. Brown the skin and the meat inside is cooked perfectly. My husband especially enjoys swordfish steaks grilled on a hot rock. Crawfish do well on hot stones too. Above all, guests to our cooking fire love our fresh water mussels cooked on a bed of hot stones. Mussels are easily the first stone-cooked dish we run out of. More than meats, go ahead and stone grill onions, potatoes, squash, peppers, and even apples. Just make sure to roll them over more or less frequently based on its skin (ex. squash may not be turned for up to 15 minutes while apples have to be more continuously turned).
Boiling
Important Note: Hot-stone cooking can be dangerous, especially hot-stone boiling, as many types of rocks or flawed stones can explode. The author tends to use granite and basalt, and stays away from sandstones, porous limestone, hollow rocks, and the like. It is highly recommended that the reader who attempts such researches the rocks of their area and their characteristics that would or would not make them candidates for cooking or boiling.
Almost every Native culture, at one time or another, practiced stone-boiling. Upon contact with Europeans, Northern Great Lakes Peoples hot-stone boiled in birch bark containers, the Plains Peoples hot-stone boiled in suspended or ground trenched rawhide vessels, and the Northwest Coastal Peoples hot-stone boiled in wooden boxes. Even in areas where pottery prevailed, hot-stone boiling was still employed, only to a lesser degree and to more specialized cooking. For example, for the Northeastern Woodland People quite known for their expert earthenware pottery, hot-stone boiling was still a great way to cook in large quantities for festivities. Some are even noted for taking old canoes and hot-stone boiling large “stews” inside. And while cold, hard parched corn could fill a hunter’s stomach, a Native man hardly thought it civilized to be without a hot meal every day, even if alone. Pottery being quite bulky and breakable (not to mention the possession of his wife who was probably busy using it) did not suit well for a single person on the move, but a small bark container or rawhide (shaped to hold water) was light and easy to cook in using hot stones. Even when iron, brass, and copper kettles were used in historic times by Native Peoples to produce Maple sugar, they still employed hot-stone boiling. After all, most families had only so many kettles and so much space over the fires. With trees producing a gallon or more a day in sugarbushes with 100-200 trees tapped, that sap had to go somewhere. And better off that sap started evaporating by hot-stone boiling than just sit and wait (to which there is a shelf life), thus reducing to at least half sugar content before hitting the cooking kettles.
While this was historically employed by the Native People to much success, remember that those who grew up with such cultural technology become experts. Do your research – which rocks will explode when treated in this manner? Realize there is a certain amount of danger, even if you know what you are doing, as correct kinds of rocks may still be structurally flawed. Also, I suggest anybody attempting to recreate such a cooking technique were goggles and possibly a helmet (I have heard horror stories, one in particular of hot limestone exploding upon contact with water and leaving its mark on a man’s forehead). That being said, hot-stone boiling is quite an amazing and efficient way to cook food. It may take a few stones and less than 1 minute for a small container (gallon or less) or several stones and 10 minutes for a larger container (5 or more gallons) to begin to boil. But once it starts, it’s easy to keep it going. A larger container may only need 1 or 2 hot stones dropped in every 10 minutes or so to keep it at a rapid boil.
