Sap dripping from the Sugar Maple Tree is one of the true signs of early spring in Pennsylvania. Trees may be tapped as early as the end of January, but the main sap flow is usually toward the end of February and into March. This sweet sap is boiled over large fires until it is concentrated into a fine table syrup. As soon as the buds begin to ripen, sometime in April, the sap becomes off-flavored or "buddy" and the syrup making season is over at this time. By being careful, no permanent damage is done to the tree. While a tree may yield sap for 100 years or more, they are usually not mature enough for permanent tapping until it reaches 30 - 40 years old. We collect sap from 11 sugar bushes which utilize about 10,500 taps, with some trees providing two or more taps. A healthy tree can accept new taps each year without harm. Each spring, after the harvest season ends, the holes begin to dry up as the tree starts to heal the wounds. Over the course of years, the trees cover over the old holes with new growths of wood leaving only a small scar in the bark.
Metal or plastic spiles are pounded into holes which have been drilled in the maple trees. Tapholes are 7/16" in diameter by 1 1/2" to 2" deep. They are drilled at a slightly upward angle to allow the sap to flow out of the hole, through the spile, into the pipeline tubing or bucket. We still use about 1,500 buckets in areas not practical for plastic tubing. It is hard work emptying the buckets everday, sometimes during a good run, we must empty the buckets several times a day so as not to allow them to flow over. Pipelines can only be used where the slope of the hill provides for gravity to pull the sap downhill and into the collecting tanks. There can be no level areas in the line and sap can't flow uphill. The bucket lines are generally utilized along the roads and areas where it is more accessible to collecting by hand.
While buckets hanging from trees is an effective means of collecting sap, we find the tubing system of collection to be more efficient. Plastic spiles, replace the metal ones. Plastic tubing replaces the buckets. Our system uses approximately 21 miles of branch line tubing (5/16" diameter) and about 4 miles of larger mainline tubing. Many branch lines will feed into a mainline as it winds it's way down the slope, from tree to tree, to the large collecting tanks and tanker trucks. With sufficient slope, closed systems, provide greater sap yield through the creation of natural vacuums. We must be careful to prevent air locks which reduce the sap flow down through the tubing.
Maple sap is easily mistaken for water, except for it's slightly sweet taste. It may take up to 55 gallons of sap to make one gallon of syrup, depending on the age and location of the sugar maple tree, the year or the time of the season.
We have many storage tanks in the various bushes. The mainlines flow into these storage tanks and run through a filter bag, to remove bits of wood and bark. The sap in these gathering tanks is then pumped out, as soon as possible, into the tanker truck and is then driven to the sugar house. The sap runs by gravity from the truck into a storage tank where it is then pumped up above the tap room into another pair of tanks which hold the sap until it is run into the reverse osmosis machine to begin separating out a large amount of the water.
A good sap run will yield 10,500 or more gallons of sap in a day. We utilize retired dairy tanks and dairy tanker trucks, made from stainless steel, and have a storage capacity of some 1000 gallons per tank to 1800 gallons per truck tank. The raw sap degrades quickly after it leaves the tree. Sap usually begins to spoil or ferment within 24 hours and must be processed within a day to make quality syrup. Filter bags are used at each point of transfer to keep out the bits of wood, etc., which is brought along with the sap flowing through the lines.
The evaporator is a 15 foot long, low pan, built over a large gas fired hearth, fired with 6 large nozzled burners. It evaporates about 490 gallons of water out of the concentrate per hour.
The fire rushes under the length of the "cooker" to the large stack at the back. The concentrated sap moves from compartment to compartment in the pan over the length of the fire, gradually thickening as it moves along. The process is continual with sap always coming in and the cooked and more concentrated sap is then moved by piping to the finishing pan. 
The finishing pan is an 8 foot evaporator, with two gas burners that is used for the final cooking to reduce the syrup to a carefully finished product. Controlled by an automatic draw off sensor which allows the syrup to be finished to with-in a very narrow increment to keep the standard of quality high and extremely uniform throughout the season.
With about 20 to 30 gallons of finished syrup being "drawn off" every hour. 
While the pans usually have only about 1 1/2" of liquid in them, the thickened sap tends to foam as it becomes closer to the syrup state, it must be watched closely and a small amount of Butter added as needed to keep the foaming under control.
We draw off syrup from the evaporator at this point. The boiling point of water changes with the barometeric pressure in the atmosphere. We may have to make adjustments as we are boiling. We do that by measuring density in a sample of hot syrup with a hydrometer. This instrument, floats at different heights in a sample of syrup depending on the liquid's density. We take samples, several times hourly, to measure the sugar content and make adjustments as are necessary for optimum quality.