On the retting of flax (pt1)

After the harvest, comes the retting. This process, put in a simple manner, is used to separate the flax fibers from the wooden core of the stalk, and it is one of the phases that most contributes to the quality and beauty of the fiber, or to ruin it if it is not done properly.
There are several methods to do theretting, but we use a natural fermentation method that is the most traditionally used in Portugal and that is done simply by submerging the stalks in water during a period of time. In the water the fermentative process will occur, carried out by the microorganisms that exist naturally in the stalks, and that will decompose the pectic substance that binds the flax fibers and the wooden core together.
It sounds pretty simple, but the problem is that being a natural process done in a place where the conditions are not controlled, there are many variables that can influence the process and that we can not control or measure accurately. At the end of a properly doneretting process, we should have the phloem, in their total length, completely loose from the wooden core, but we don't want the process to go so far as to break the fibers in their most elemental portions or, even worse, let the stalks rot. 

Failing at this phase is not very difficult, especially when the process is being carried out in a new location for the first time, like we're doing in Parque da Devesa. To be sure of the time the flax should be kept underwater, in this specific tank, and if it has the right conditions, we can only know it for sure after doing the process for the first time.
Even so, if we're doing it for the first time there's a couple of tests we can do a few days after the retting process has started (6 or 7) and that can help us decide if it should be taken out or left for a few more days.
One of the tests, that is also used traditionally and that I learned from Teresa and also from Abílio, consists in taking several stalks from different bundles, tying them in a knot and throwing them into the water again. If most of them float, the process is not over yet. If most of them sink, it is time to put the flax out to dry.

Five stems randomly taken from the bunches that were submerged in the tank for the retting process.

All of the stems sunk, so I decided to remove the flax bunches from the tank.

The second test, that I learned from Fátima, consists in taking a stalk in your hand and making your thumb and index slide tightly up to the top. If the outer layer, which is basically comprised of flax fibers, slides off easily, then it is separated from the wooden core and the retting is done. Please note that the fibers will also slide off if they are over retted, so this test should be done frequentely, starting 5/6 days after the beginning, when the fibers won't slide, and done until they do, taking the flax immediately out.

We place our fingers on the bottom of the stalk and slide them up to the top.

If the exterior layer, which is basically composed of flax fibers, comes off easily from the wooden core, then it is time to remove the stalks from the water.

Generally, retting will take 8 days minimum, if done in a big tank with flowing water. If I'm doing it for the first time somewhere new, this is the time I'm aiming for. If I'm not very sure, I'll rather take the flax out sooner than later. If the flax is not retted enough, it will be harder to process, but at least the fiber will be whole. If it is over retted, I'll end up with smaller fibers or, even worse, rotten flax.
After the retting is done, theflax is removed from the water and placed to dry. In some places the stalks are washed first, to remove the "dirty" water. This helps to whiten the fibers.
The bunches must be immediately opened and the stalks spread on the ground or in vertical piles, to dry. Drying will take at least another week, but probably a few more days. It's easy to check if the flax is well dry, just by grinding the stalks with your hand and checking if the wood brakes easily and clearly.

A few notes: it is also possible to dry the flax immediately after harvesting, before retting. Since this implies waiting a few more days before carrying on with the process, it has no interest for us, but it could be useful if you have a few limitations. For instance, if you can't rett all the flax at once or if you just want to do it at a later time.. If the retting is done using the dry stalks, I believe it will take a couple more days than if done using fresh stalks from the start.
Also, there's also the option for dew retting, which is a more known method. It is more useful if you don't have a place with running water to do the water retting, and it is easier to achieve the "right spot" because it is a much slower process than the one I described earlier. But exactly for taking a lot more time and demanding more attention, it is not as practical for me. I prefer to put it in the tank and get the process over with in 8 days.