Sunday, April 1, 2012

Cooking in a Bentwood Box


Boiling at the Burke
Prior to the trade of steel cookware in the Pacific Northwest, the Native Americans prepared many foods in wooden cooking boxes.  Instead of putting the box on a heat source, red hot rocks were placed inside of the cooking box to cook food.  As you can imagine, some knowledge and specialized equipment are needed to safely heat cooking rocks and build a cooking box that doesn’t leak.  This weekend as part of the Burke Museum’s Traditional Northwest Native Foods and Diets event, I demonstrated how to boil water in a bentwood box.  What follows is a brief discussion of the equipment and some photos.

A storage Box on display at the Burke
The Box:
Native Americans in the Pacific Northwest constructed boxes from two types of wood for a variety of purposes.  The planks of Western Red Cedar (Thuja plicata) and Alaskan Yellow Cedar (Callitropsis nootkatensis) were carefully split from standing trees or fallen logs with yew wood (Taxus brevifolia) wedges.  These plants were then painstakingly hewn into boards of a consistent thickness using stone adzes.  Three kerfs (grooves) of nearly the thickness of the board were chiseled into the board at regular intervals so as to provide bending points for the wood.  The board was then soaked and heated/steamed until the wood was soft enough to bend into a rectangular shape around a wooden base.  All the joints were then fastened with pegs or laced with Red Cedar or Sitka Spruce (Picea sitchensis) roots.

Clay sealed joint
Bentwood boxes were used for cooking as well as storing food, clothing, and ceremonial items.  Cooking boxes ranged in size from that of a medium saucepan for everyday cooking to colossal vats capable of holding hundreds of gallons for rendering eulachon grease.  Whatever the size, the cooking boxes had to be water tight, and that is where the bentwood design really shines.  Because the sides of the box are made from only one piece of wood, there are fewer joints to worry about leaking.  The natural expansion of wood when exposed to water helped seal the joints, but according to the Kwakwaka’wakw (Kwakiutl) elder Agnes Alfred (in her biography “Paddling to Where I Stand”), clay was also used to seal joints and cracks.  Clay works well because it expands when wet, doesn’t dissolve easily, and is non-toxic.

Vesicular basal  cooking rocks
The Rocks:
Special cooking rocks are used to transfer the heat of the fire to the water inside a bentwood box.  While any old rock might work, vesicular basalt—a type of semi-porous black volcanic rock—was preferred by most tribes because it heats up quickly without cracking.  Most other rocks crack easily when heated and constantly replacing heavy cooking rocks is an irksome task.  Golf ball to tennis ball sized rocks heat up quickly and are easy to move.

To heat the rocks they are placed on a cooking hearth and a hot fire kindled on top of them.  After about 45 minutes, the lava rocks get so hot that they glow faintly and are ready to be moved to the water filled bentwood box.  Rocks play the role of your standard heating element for boiling water.  The temperature and surface area of the rocks (and temperature and volume of the water) determine how quickly the water will come to a boil.  If my rocks are glowing hot, I find that I can boil water in the time that it takes to move 30 cooking rocks.

The Tongs:
Hazelnut fire tongs
Traditionally, wooden tongs would be used for safely moving hot rocks.  Tongs were either made from a forked branch or a straight branch that is mostly split in half lengthwise.  In either case, the long straight sucker growth of Big Leaf Maple (Acer macrophyllum), Ocean Spray (Holodiscus discolor), or Hazelnut (Corylus cornuta) were often used on account of their hard, fire resistant (when green) wood.  I often use metal tongs to move my rocks because they grip the rocks a little better, but it is nice to know how to make fire tongs when in a pinch.

My mentor Clan Chief Kwaxsistalla taught me how to construct and cook with bentwood boxes.  You can read more about him and this cooking technology in my Master’s thesis.
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