Maple syrup is made by boiling between 20 and 50 litres (5.3 and 13 US gal) of sap (depending on its concentration) over an open fire until 1 litre (0.26 US gal) of syrup is obtained, usually at a temperature 4.1 °C (7.4 °F) over the boiling point of water
from http://en.wikipedia.org/wiki/Maple_syrup…
Maple syrup is made by boiling between 20 and 50 litres (5.3 and 13 US gal) of sap (depending on its concentration) over an open fire until 1 litre (0.26 US gal) of syrup is obtained, usually at a temperature 4.1 °C (7.4 °F) over the boiling point of water
from http://en.wikipedia.org/wiki/Maple_syrup…
I’m thinking it is a 30:1 ratio…..maybe higher.