Tapping activities and weather

In southern regions of the province, daytime temperatures have warmed to help thaw sapwood in sugar maple trees.  Nighttime temperatures are just a few degrees below 0 °C.  These thawing conditions have enabled tapping of maple trees to begin in southern regions of the province.  The sap was flowing during tapping on February 19 and 20.   In northern regions, low freezing nighttime temperatures and colder daytime temperatures will keep sapwood frozen solid and tapping is not recommended until sapwood thaws.

Remember that tapping frozen sapwood can lead to splitting of bark above and below the tap holes.  Where splitting occurs, sap will dribble out the split and down the tree trunk instead of into spouts.   Several consecutive days of thawing conditions are required to thaw sapwood adequately for drilling tap holes.

Photo 1.   This is a new sanitized 5/16 inch spout for bucket collection.  The function of the spout is to transfer fresh sap to buckets or tubing, provide attachment for buckets or vacuum tubing to the spout and, maintain the tap hole in a sanitized condition for as long as possible during the sap collection season.  Only proper food grade containers should be used for sap collection, sap transfer and storage.

Selecting a spout (also called spile)

Many syrup producers that have vacuum tube sap collection are using polycarbonate seasonal spouts, which are discarded following each season of use.   Most polycarbonate spouts are transparent, which enables producers to inspect for good sap flow and for plugging by wood shavings while installed in the tap hole. 

Photo 2.    Polycarbonate spouts will reshape to the tap hole once it is installed for an improved seal and less occurrence of vacuum leaks.   A standard black re-usable spout is top left.  Seasonal check-valve spouts (second spout down on left) will help prevent  back flow of bacteria-laden sap into the tap hole. 

Studies have found that it is very difficult to clean bio-film and sugar residue from the inner surfaces of plastic spouts and tubing after the season.  Used spouts and older tubing are a source of spoilage bacteria which can quickly enter into freshly drilled tap holes.  Back flow of sap is a result of natural vacuum that develops within the trees between sap runs, while trees are recharging with new sap.

Photo 3.  Researchers have found that sap yields will remain high where new spouts are installed each year.  Researchers recommend drop lines should be replaced with new tubing every three years to maintain high sap yields and cleanliness of tubing.  Researchers are working to improve cleaning recommendations and to develop new plastic materials to reduce waste of plastic.

Good food grade practices

All equipment that will be in direct contact with sap or syrup should be constructed of food grade materials for the purpose of food production.  Food grade equipment will be used for the collection, transport and storage of fresh sap, for processing of sap into maple syrup, as containers for hot-packed syrup intended for sale, used in the making of value-added maple products and, required to store bulk syrup.   Manufacturers of maple equipment can supply any item needed and will be made of acceptable food grade materials.

Photo 4.  Tig-welded stainless steel pans, steam hoods, vents, smokestack, valves and fittings can be cleaned and sanitized for food production.  Note the washable concrete floor and walls.  A metal heat shield should be installed between the smoke stack and building structure with adequate separation to prevent a structural fire.  An air space of at least 2 inches should also separate the heat shield from contacting the building structure.

If you have purchased used maple equipment, unsafe materials include tin, galvanized metal tanks, old stainless steel containers or evaporator pans that are joined with lead solder, brass valves / fittings and containers or piping made from non food grade plastic.  Unsuitable equipment should be replaced.  Safe materials include tig-welded stainless steel and food-grade plastic.  For commercial sale, containers used to sell finished maple syrup must be new, sanitized, and made of metal, plastic or glass intended for sale of maple syrup or food products.

Photo 5.  Tig-welded stainless steel drums are cleaned, sanitized and rinsed with potable water in preparation to store bulk maple syrup.  Hot packing syrup at a temperature of 85 C (185 F) will prevent spoilage by mould.  Some producers store sealed bulk syrup in refrigerated cold storage as an added guarantee of quality.