Collecting maple syrup sap from maple trees in the springtime is a northern tradition. The trees will produce sap for boiling as the days become warmer, and the nights remain in freezing temperatures. This process is highly dependent upon favorable weather conditions.
The business of maple syrup has become very technologically based. Sugar makers have upgraded their sap collecting to pipelines, and boiling pans are controlled by automation. The traditional collecting of sap buckets by sleds and wood-fired furnaces is strictly for personal use now. Commercial vendors can supply maple syrup systems for anyone trying to market large quantities from their sugarbush.
Evaporator pans should be centered over the furnace with divisions where the sap can flow from one side to the other during boiling. Wood heat sources are traditional but may be more difficult to maintain constant temperature than gas furnaces. The evaporator pan could be a simple large stew pot, if you want to make just a couple gallons of syrup per season.
When boiling, divide up the evaporator pans such that you can push through the sap as it thickens from one side of the large pan to the other. The hottest part of the evaporator pan should be the middle sections, where the most steam is created. The side where you introduce new sap, and run out the finished maple syrup should be cooler than the boiling sections of your evaporator pan. If using a large pot, you will only be able to make one batch of syrup per pot of sap.
As the sap boils, the color and consistency will change. You can use butter along the edges of the evaporator pan to keep the maple sugar from boiling over the sides of your pan. Watch the sap carefully, and test the quality frequently to ensure you do not over boil your syrup into candy.
Maple syrup evaporator pans vary according to the size of the furnace for boiling. Most evaporator pans are steel or aluminum. Anybody can reduce maple tree sap by creating pots of sap and varying the stages of boiling over a heat source.
Do not fight the weather. Sap runs when nature provides the perfect conditions. Collect sap early, in case the weather turns warmer quickly.
Sap for maple syrup should be clear, not milky. It should taste sweet, with no aftertaste, or pungent smell. Discard sap that is not optimal. Do not contaminate your sap storage by inadvertently collecting sap that is too old, or been too warmed in storage.