Figure 4. Modern machine method for washing soft 

 varieties of seaweed. 



kilograms of seaweed and al^out 3,400 liters of water. 

 the boiliiig process is a typical plant follows. 



importance in the 

 production of a 

 pure product of 

 high quality.. 

 Table 2 shows the 

 most desirable 

 proportions of the 

 various kinds of 

 seaweeds blended 

 in each batch. 

 The tanks used for 

 the boiling process 

 are mada of wood 

 and are large 

 enoiigh to hold one 

 batch or about 225 

 A description of 



b. The water is placed in the boiling tank and a fire is 

 started in the brick fire box under the tank at 1800 hours. Wood should 

 be used for this purpose to minimize the dust and soot in the vicinity of 

 the drying agar-agar. The water should be boiling by 2000 hours; at 

 this time the hard varieties of seaweed are added. The addition of the 

 seaweed stops the boiling. When it is resvuned, approximately 740 grams 

 of sulphuric acid are added to help break down the hard outer covering of 

 the seaweed and to control the Ph value of the batch. Care must be taken 

 to see that too much sulphuric acid is not added, as the Fk value of the 

 finished product should not be above 6.5 or 7.0. Hard weeds are boiled 

 for one and one-half hours, and then the soft weeds, iglso and ogo, are 

 added. This mlxtta-e is boiled for 15 minutes. Then the softest weed, 

 ego, is added. When the ego is added, no more wood is placed in the fire 

 box, and the active boiling stops. The entire batch Is simmered for 12 

 hours or until about 1000 hours the folio- :.. ^- day. 



c. When this boiling is completed, the so-called "second 

 boiling" of the previous batch (explained in a later pso'agraph) is added 

 and r em a i ns in the tank for four hours. This is an overall time of 

 between 16 and 18 hours for the complete boiling process of one batch. 

 During this process it is important that the water not boil too vigorous- 

 ly and that the seaweed be stirred frequently to permit a gooa circu- 

 lation of heat. Prior to the war about five minutes before the liquid 

 was removed from the boiling tank two pounds of sodium dioxide were added. 

 This chemical was used as a bleaching agent. Since it was imported from 

 G-ermany, imports have now stopped. Consequently, none of this chemiceil 

 has been used in the last few years, and the agar-agar produced has not 

 had such a white color as when the bleach was used. 



