A basic approach to water-ret small amounts of flax straw
We recommend 48-inch metal stock tanks from Tractor Supply, preferably with a drain plug, which makes changing the water much easier. However, practically any kind of tub can be used, including children's plastic wading pools, a bath tub, we even know a person who used a rain barrel. However it is easier to work with the straw when it is horizontal instead of vertical.
Water temperature is crucial and critical. Retting works best in warm water, which is why we pond ret in the heat of summer, actually when the algae bloom is in the water because we know then that the conditions are right for the growth of the anaerobic bacteria that do the actual retting by eating the pectin, or the naturally-occurring glue in the plant that binds the fibers to the stalk. Without this bacteria growth, retting cannot work properly, and cold water inhibits bacteria growth. Retting is primarily warm-weather work. If it is attempted from late fall to spring, then it must be done indoors in a heated environment, such as a heated garage or workshop.
Up to 10 pounds of straw can be done in a metal stock tank. It's not good to pack too much straw together; ensure that water can reach all the stalks. The straw needs to be held underwater; pieces of wood, bricks or stones are good for this.
Cover the straw completely with water with several inches above the straw if possible. Every day, drain or scoop out one quarter of the water and replace it with fresh water. After a couple of days, bubbles should be forming; this tells you that the bacteria are there and doing their thing.
Soak the straw for four days in warm water, then test the retting by bending a couple of flax straws to see if the fibers are separating from the stalk. If so, take the straw out and completely dry it, which will take several more days. When dry, check the flax again by bending a couple of straws. There should be a distinctly audible snap as the straws break and the fibers are released. At this point, the straw is ready for breaking. It can also be stored for an indefinite period in any dry space, such as an attic, a barn, stable, etc. If the straw is under-retted, put it back in the water for another day, then dry again and check it. If the flax fibers fall completely apart, then the straw has been over-retted. Under-retting is not a problem as the retting can always continue until the fibers cleanly separate from the straw. Over-retting destroys the crop. It's always better to under-ret than over-ret.
Questions or comments: firstname.lastname@example.org; call 570-492-4832; or write us at the Hermitage, 75 Grove Road, Pitman, PA 17964.
Also check out our YouTube videos for water and ground retting. These are just two of the videos; make sure you start at the beginning of each series, one on ground retting, and one on water retting.