Keep boiling until the sap thickens and turns a brown color. The syrup is ready for canning when its temperature is seven degrees above the boiling point of water. This is easy to decide by using a candy thermometer. Pour the hot syrup through a felt or cotton strainer into your canning jars. Leave as little air space as possible, and cap immediately for storage.
Maple syrup is a pure, all natural product.
Do not use sap that is cloudy or has sat too long in the buckets through warm temperatures. Collect all your equipment at the end of the season and wash it thoroughly. Also, you should wash it again at the beginning of the season next year. Do not plug your old tap holes at the end of the season. The tree will naturally heal this wound within two years.