This section is from the book "A Treatise On Beverages or The Complete Practical Bottler", by Charles Herman Sulz. Also available from Amazon: A Treatise On Beverages.
Various other practices in preparing syrups by the cold process are followed.
One of them is to use a perforated diaphragm made of copper, silver-plated, or wood, placed in a tank or barrel just above the cock, three or four inches from the bottom. Cold water is poured over sugar resting en this diaphragm, and the syrup which trickles through is drawn off and poured over the sugar again. This process is repeated until the syrup indicates the required strength on the saccharometer. This means preparing syrups by percolation, and is too tedious an undertaking for practical purposes and large requirements.
The way of making syrup by saturating the water with sugar, that is, to dissolve as much in the water as it is capable of, is another practice followed to a certain extent; but some manufacturers, actuated by economical desires, found that saturation is not only unnecessary, but also undesirable, as a syrup with a slight excess of water keeps better than one fully saturated. An authority on this subject says: In saturated syrup a portion of sugar generally crystallizes out on standing, and thus, by abstracting sugar from the remainder of the syrup, so weakens it that it rapidly ferments and spoils. This change proceeds at a rapidity proportionate to the temperature. Saturated syrup kept in a vessel that is frequently uncorked, or exposed to the air, soon loses sufficient water, by evaporation from its surface, to cause the formation of minute crystals of sugar, which, falling to the bottom of the vessel, continue to increase in size at the expense of the sugar in the solution. On the other hand, syrup containing too much water also rapidly ferments, and becomes sour; but of the two this is the lesser evil, and may be more easily prevented.
Fig. 410. - Stone-ware Syrup Mixer.
The proportion of sugar and water given previously will form an excellent and reliable syrup, is much quicker prepared, and does away with unnecessary arrangements, saving time and giving good practical results.