These small bricks are called Dutch bricks because they were produced in the Netherlands and imported to Virginia beginning around 1630. They may have been imported for specific purposes at Jamestown or they could have arrived as ship ballast only to be repurposed in buildings in Virginia. Dutch bricks are much smaller than bricks produced locally, measuring approximately 6.5 inches long by 2.9 inches wide, and only 1.4 inches thick. Also unlike familiar red-colored, Virginia-made bricks, Dutch bricks are often predominantly yellow in color. They are sometimes called klinkers or clinkers, which is derived from the Dutch Ijsselsteen or Ijessel-klinkers.
At Jamestown where there was plenty of land area, bricks were made using clay harvested from pits dug around the island. In the Netherlands where land was limited and valuable for farming, Dutch bricks were made from clay found in tidal river mud, like the Hollandse Ijssel River near Gouda, or from different lakes in the Netherlands. The tidal pits created by brick manufacturing would naturally refill with clay, saving surface area that would have been made unusable if it was mined for clay. The tidal clay was very wet and soft which influenced the small size of Dutch bricks — if they were made larger they would not have held their shape.
The Dutch bricks were fired in a kiln called a clamp, often firing 100,000 or more bricks at a time, a process aided by the employ of women and children. Men would mix the clay for the bricks until it reached its desired consistency and mold the bricks. Women and children would unmold and lay out the bricks for drying. To produce raw bricks the molds were dipped in water then covered in sand, clay was worked into the mold, and then a child would take it to the drying area to tip the bricks out to leave them to harden. The sand would have aided in the removal of the wet brick from the mold; a process that Jamestown brickmakers also used to produce stock bricks on the island.
Variation in sizes of Dutch bricks are due to different mold sizes being used in different places in the Netherlands, and also as a result of the clay and firing process. Brick making season lasted from April through the end of the year, and as the raw bricks dried in the open-air during the summer, children would walk the rows of bricks turning them on their sides to help them dry further. This method caused slumping and uneven drying, resulting in slightly misshapen bricks. The bricks would also shrink when fired in the clamp causing some of them to be oblong or to taper to one edge. Once the bricks were properly dried, it was the responsibility of women to transport wheelbarrows of bricks into a holding place until firing or possibly move and arrange them in the kiln itself. A worker would often move over 150lbs of unfired bricks in a 7-10 hour work day. Bricks were then fired for a minimum of four weeks in temperatures ranging from 1652°-2282°F, depending on what the brick was going to be used for. After firing and cooling, the inspection process began with sorters looking at the hardness and color to determine the price of the bricks. While their color most likely is due to the minerals in the brick-making clay, brick color can also change depending on firing technique and brick location within the kiln. Clay with a high iron content, like that found in Virginia, produces red colored bricks, while clay with a high calcium content produces buff colored bricks. Organisms in the clay used to make Dutch bricks made it rich in lime, giving some bricks their distinctive yellow color.
Smith, Terence Paul and Terrence Paul Smith (2001) On ‘small yellow bricks … from Holland’ Construction History, 2001, Vol. 17, pp. 31-42. The Construction History Society.
Becker, M.J. (1977) “Swedish” Colonial Yellow Bricks: Notes on Their Uses and Possible Origins in 17th Century America. Historical Archaeology Vol. 11 pp. 112-118. Linsten, H.W. (1993) History of Technology in the Netherlands. The Emergence of a modern society 1800-1890. Part III. https://www.dbnl.org/tekst/lint011gesc03_01/lint011gesc03_01_0014.php