How It Works
The Freeze-Thaw Cycle
Maple sap flows when nighttime temperatures drop below freezing and daytime temperatures rise above freezing. This creates pressure changes inside the tree that push sap through the tap.
What the Ratings Mean
- Excellent: Ideal freeze-thaw — overnight lows of -7°C to -2°C with daytime highs of 4°C to 10°C.
- Good: Solid freeze-thaw cycle — freezes overnight, thaws above 2°C during the day.
- Fair: Marginal — some freeze-thaw activity but temperatures are outside the ideal range.
- Poor: No freeze-thaw cycle — either too warm (no freeze) or too cold (no thaw).
Consecutive Days Matter
The best sap runs happen during extended stretches of freeze-thaw days. A single good day produces less sap than a 5-day run. The "Best Tapping Window" highlights the longest stretch of good-or-better conditions in the forecast.
Tapping Guides
Choosing & Tapping a Tree
Pick a healthy sugar maple at least 30 cm (12 in) in diameter. Place the tap above a large root or below a large branch on the south-facing side for the earliest flow.
- Tree size: 12–18 in diameter supports one tap; larger than 18 in can take two (Vermont Evaporator Co.).
- Drill: Use a 5/16″ or 7/16″ bit, about 5 cm (2 in) deep at a slight upward angle.
- Check your shavings: Light-coloured chips mean healthy sapwood — dark shavings mean pick a different spot (Tap My Trees).
Collecting & Boiling
Hang a food-safe, lidded bucket or attach tubing to the spile. Collect sap daily and refrigerate it — sap spoils quickly above freezing.
- Ratio: It takes roughly 40 litres of sap to make 1 litre of syrup.
- Boil outdoors: The steam will peel wallpaper indoors (Old Farmer's Almanac).
When to Pull Your Taps
Without the freeze-thaw cycle, sap flow stops. Watch for these signs that the season is over:
- No more freezing nights: Once temperatures stay above freezing consistently, flow dries up (Mother Earth News).
- Bud break: Once buds appear on the branches, sap develops an off "buddy" flavour that won't make good syrup. Pull your spiles before buds open.
End-of-Season Cleanup
Remove spiles with pliers and let tap holes heal on their own — don't plug them.
- Clean equipment: Scrub with dilute bleach (1 part unscented bleach to 20 parts water), then triple-rinse with hot water (Tap My Trees).
- Store dry: Keep spiles, buckets, and lids in a dry, dust-free place until next season (Vermont Evaporator Co.).