Inside the Tree

Maple trees stop growing in the summer and fall and begin storing excess starches in ray cells. The starch remains in storage as long as the wood remains colder than 40°F. When the wood temperatures reach 40°F, enzymes in the ray cells cause the starches to change to sugars, and the sugar is passed into the sap.

Once the wood temperature reaches 45°F, the enzymes stop producing sugar, and as the temperatures continue to warm, any remaining sugar is changed back to starches.

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