What is an RO Machine?


Picture of the machine coming soon!

A reverse osmosis (RO) machine is a filter.  It was originally created to purify water.  Maple sugarmakers got a hold of them, and used them to discard the pure water and keep the contaminated water (full of sugar, minerals, etc.) in order to further process it into maple syrup!

A sugar molecule (C6 H12 O6) is much larger than a water (H2O) molecule.  Maple sap out of the tree usually ranges between 1 and 3 percent sugar. A reverse osmosis machine can increase the sugar content to over 20 percent.  In order to get to Pure Vermont Maple Syrup (66.9% sugar) the remaining excess water is removed the traditional way – through boiling the sap until enough water has evaporated for the syrup to be the correct density.

Though there have been some poorly run tests to see if ROs have a detrimental impact on flavor and none of them have been conclusive (shocker) – it is believed by many that the combination of high concentration RO use and using fuel other than wood leads to maple syrup with less flavor.

Think about it – Instead of cooking something for 100 minutes as the recipe calls for, you cook it for only 12.5 minutes…. How would it taste?  That’s what is happening with 2.5% sap when it hits the evaporator vs. 20% “sap” when it hits the evaporator.  If you are like my friend Orin – the Thirty Second Guy (check out his other videos!), maybe 30 seconds is okay for cooking some things, but for me I like flavor in my syrup.

At Green Wind Farm, we do have an RO and we run it at 7%.  This way we don’t need to cut, stack, split, stack, dry, move into woodshed and burn 70 cords of wood a year to make our syrup, we only use about 25 cords or so!  Seriously though, let us know if you find syrup that can compare to ours on a regular basis.  We always want to figure out how we can do things better.

New in our operation this year is an oil dripper, so we can minimize the amount of defoamer we use to keep the boiling sap in the back pans from flooding over.  We have used local organic sunflower oil in the past, but will likely use an organic safflower this year as we are suspicious the sunflower was imparting a slight flavor to the syrup.




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