24 



HARDWOOD RECORD 



slow yield of frost from ground, which makes the sap flow long and 

 continuously enough to give a paying production of sugar. A sudden 

 thaw affects both the quality and the quantity of the sap flow. Ideal 

 weather for sugar production is warm, sunny days and cool nights. 

 Cool rainy weather is not conducive to a vigorous flow. 



For these reasons it is always desirable to maintain the best forest 

 conditions in the grove, for if the ground is carpeted 'ii'ith a heavy 

 layer of leaves and humus it will be less sensitive to changes in 

 temperature. 



The model grove should satisfy the following conditions as far as 

 possible. 



1. It should ciintain the greatest number of trees per acre consistent 

 with fully developed crowns. 



2. The forest cover should be unbroken so that in summer little sun- 

 light falls upon the ground. 



3. There should be a complete litter of humus and leaves, to the ex- 

 clusion ol grass and light demanding weeds. 



4. Young trees should be kept in reserve to take the place of those 

 that tall, and to fill other openings in the cover. 



5. No grazing should be allowed in the grove. ^ 



6. The grove should be made accessible by a system of roadways to 

 facilitate the collection of sap. 



These conditions are somewhat ideal, and only an attempt can 

 be made to observe all of them. 



The best location for a sugar grove is where the ma[)le thrives 

 best. In the southen Appalachians, the groves on the northern 

 slopes have the most desirable location, while in the middle state.s 

 the moist, gravelly soils are the best. In the northern states where 

 the maple does well on all exposures, tlie south one is preferred, be- 

 cause the sap of trees on such locations starts earlier. 



MAPLE SAP 



It is commonly supposed that the sap of a tree flows uji from 

 the roots in the spring and back to them in the fall, but this is 

 not true, for when the trees are tapjied as much sap comes towards 

 the hole from above as from below. There is even sap flow from 

 each side of the hole. The flow varies with the season, the day, and 

 the temperature. Experiments have been made and as a result it 

 was found that the force exerted by tlie sap on maple trees in the 

 sugar making season varies from a suction of two pounds per square 

 inch at night, to a pressure of twenty pounds per square inch during 

 the day. The rise and fall of the tem]icrnfure is responsible for 

 this. 



The sap season usually begins about the middle of March and 

 continues until the third week in April. It varies with an early or 

 late spring, and, of course, is later in the North than in the southern 

 part of the region where the industry is carried on. 



It is very difficult to determine the average yield of trees, but 

 it can be said that a mature thrifty maple will produce about twelve 

 gallons of sap, or three pounds of sugar ]ier season. Instances have 

 been recorded of trees having averaged ninteen gallons of sap 

 per season, and of one tree having produced enough sap to make 

 thirty and three-fourths pounds of sugar cake in one season. 



Maple sap is a nearly colorless liquid composed of water, sugar, 

 mineral substances such as lime, potassium, magnesia, and iron, and 

 a small amount of vegetable acids. The flavor does not come from 

 the sugar, but from some one or all of the constituents. Careful 

 experiments have shown that on an average the sap contains about 

 three per cent of sugar. 



MANUFACTURE OP SUGAR AND SYRUP 



An increased demand for sugar and syrup has brought about great 

 improvements in the industry. The small growers still practice 

 some of the old methods, but the commercial growers are constantly 

 improving their equipment. 



As soon as the sap is running, the trees are tapped. A spot on 

 the sunny side of the tree is selected as the place to bore the hole. 

 All loose bark that might fall into the sap is brushedoff. The hole 

 i.s made with a three-eighths or one-half inch bit, bored to a depth 

 of one inch. Experiments have shown that this is the most prac- 

 tical depth. Trees under twelve inches in diameter should not be 

 tapped. The spouts afe then inserted. The most improved kinds 

 are those made of metal and having one end threaded so that it 

 can be screwed into the augur hole. In some places wooden spouts 



of sumach or elder are still used. The sap is caught in pails which 

 are usually provided with covers to keep out impurities. 



Small growers gather • the sap with buckets, carrying it to the 

 sugar house. Where the industry is carried on on a large scale, 

 large tank wagons are used, and in some places pipe lines are used 

 to convey the sap to the sugar house. The sap must be gath.nred at 

 least once each day, and sometimes twice. This is because the tem- 

 perature may become suBSciently high to cause the sap to sour. 



The sugar house is usually a substantial, but inexpensive build- 

 ing. Its main part consists of an evaporating room. In the roof 

 over this room is a ventilator which allows the steam which arises 

 from the sap as it boils to escape. A large storage tank is also 

 part of the equipment. This is usually placed on a side hill next 

 to the sugar bouse, or is elevated. The sap then moves through the 

 appartus by force of gravity. The tank is protected, so that it is 

 proof against the extremes of the temperature. 



The sap is run from the storage lank to the evaporator. This is 

 an open pan, six inches deep, forty inches wide, and from ten to 

 eighteen feet long. They are usually made with corrugated bot- 

 toms, to increase the heating surface. Partitions from side to side 

 and open at alternate ends are placed in them at intervals of from 

 eight to ten inches. The sap enters the evaporator at one end and 

 flows slowly across the pan from side to side, around the partitions, 

 until it reaches the opposite end. The rate of its flow is so regu- 

 lated that it has reached the proper density when it reaches the other 

 end. The flow is regulated according to the amount of heat the sap 

 is receiving. 



Underneath this pan is the firebox. This is built arch-shaped at 

 file front end of the [lan, its flue coming underneath the pans to 

 the opposite ends. The pans are thus heated for their entire length. 

 The sap is kept at a depth of one and one half inches at the upper 

 end, and one inch at the lower. As the impurities rise to tlie surface 

 they are skimmed off. When the syrup reaches the temperature of 

 219 F., or a weight of eleven pounds to the gallon, a deposit of 

 mallate of lime gradually commences to coat the pan. The syrup 

 is then dipped out and strained through flannel, this removing the 

 deposit. After ten or twelve hours the last two sections of the pan 

 become more or less coated with this deposit. The pan is then turned 

 around and the sap dissolves the lime, and it can then be caught in 

 the strainers. Care is always taken that the syrup finishes at the 

 proper temperature and weight per gallon. Much discussion has arisen 

 regarding whether the syrup should be put up hot or cold. Both 

 methods arc used, but it is generally observed that the syrup has 

 a tendency to crystallize when put up warm. Square, oblong, or 

 round cans of one gallon, or one quart volume, are the popular pack- 

 ages in which the syrup is placed upon the market. 



In making sugar, the syrup is reboiled in a sugaringoff arch until 

 it begins to crystallize. This apparatus consists of a fire-box similar 

 to the one used under the evaporator, but smaller in size. It has an 

 open pan above it. The point of sugaringoff used to be determined 

 by pouring a little syrup on the snow or by dipping a twig bent 

 into the shape of a loop into the syrup. If the .syrup becomes waxy 

 on the snow, or formed a film within the loop, it was ready to sugar. 

 Under modern methods the temperature is observed, and different 

 temperatures denote different qualities. The temperature is slowly 

 allowed to fall and then the syrup is poured into moulds and allowed 

 to become sugar. The products are then stored in a cool, dry store- 

 room, as heat and moisture cause the sugar to mould, and the syrup 

 to ferment. 



The opportunities in this industry are becoming more attractive 

 owing to the grejiter demand of maple syrup and maple sugar and 

 their recent rise in value on the market. It is expected that the maple 

 sugar business on a commercial basis will develop into an excellently 

 paying proposition. 



So much depends on the man at the lever in the sawmill that 

 he should be appreciated and well paid, and should in turn 

 appreciate his responsibilities and use his brains as well as his 

 hands, for a little thinking often makes a big lot of difference in 

 the value of the mill product. 



