Plate XXX. Unopened buri leaves.
The Arayat Process.—Mr. Robert Clauson, supervising teacher, has determined the process of whitening buri straw in Arayat, Pampanga, as follows: The segments are separated from the midrib and rolled rather loosely, so that the water may pass between them, in bundles as large around as a plate. These are placed in a large can or vat containing tamarind leaves and alum (see bleaching agents) in water, and the whole is boiled until about one-half of the water has evaporated. During the boiling the buri must be tightly covered with tamarind leaves and not be allowed to project from the water. After this process the rolls are placed in a jar full of clear water and left to soak for three days. The strips are then washed several times in the river during a period of three days, and they are then laid on the grass or along fences to dry after each washing. The oftener they are alternately washed and dried the whiter and tougher will the material be. After the final drying, which should be thorough, the strips are rolled very tightly into bundles.
The San Luis Method.—The method of whitening buri straw followed in San Luis, Pampanga, is described by Mr. James H. Bass, supervising teacher. The unopened leaves are brought down the Chico River in rafts. The segments are torn from the midrib and boiled for four hours in five gallons of water to which one liter of nipa vinegar, a lump of alum the size of an egg, a handful of tamarind leaves, and a handful of pandakaki leaves (see bleaching agents) have been added. Other steps follow as in the previous process.
The Mauban Process.—The following description is taken from Circular No. 27, series 1911, of the Division of Tayabas. Let the unopened leaves, cut from the stalk, stand in a cool shady place several days, until the sap has well run. Open the leaves and separate the segments from the midrib with a sharp knife. Put these carefully into a petroleum can or other suitable receptacle filled with a boiling solution of two-thirds water and one-third white nipa or coconut tubá vinegar (see bleaching agents). Keep the solution boiling until the segments are cooked so soft that folding them leaves no crease.
Spread the cooked leaves on clean grass in the sun to dry. The drying process may require one or two days. When the segments are quite dry, prepare a jar with clear soft water, and put them in this to soak over night. In the morning remove them from the jar, wash them thoroughly in clear running soft water and place them in the sun. At noon repeat the washing process until the segments open, then dry thoroughly in the sun.
It is customary to roll the buri into coils in order to make it more convenient to store. The dry leaflets may be made flexible for this purpose by laying them on the grass in the night air. After a few minutes they will be flexible enough to roll. Care must be taken to have the segments smoothly rolled. When used, they should be smoothed carefully and then split into the widths required.
The process can also be followed with rice vinegar (see bleaching agents) substituted for the tuba vinegar.
Wash two chupas of rice and cook it in water until it becomes very soft and starchy. Put this in a clean petroleum can and add cold water until the can is two-thirds full, then cover the can and let it stand five or six days. This mixture will become very sour. Strain it through a piece of sinamay or other cloth. Cook the segments in this mixture instead of in the solution described in the first process, and then carry out all the other steps.
The Romblon Process.—In Romblon, great care is exercised as to the age of the unopened leaf taken for the production of straw. If it is intended to produce bleached straw, stalks having stems about two inches long are selected. In the following description, which was submitted by Mr. R. L. Barron, head teacher, one unopened leaf is taken as a unit. The midribs are removed and the segments are rolled into round bundles, say by fives. These are boiled in clear water for about three hours. The leaves are then placed in a mixture of half a liter of tuba vinegar (or three liters of vinegar made from cooked rice, or one-fourth liter of lemon juice) to which enough water has been added to cover the rolls of buri, and boiled for about five hours. The material is then spread in the sun for three days to dry, care being taken that it is not exposed to rain or dew. The segments are then placed in cool clear water for twelve hours and again placed out in the sun for two days to dry.