An RO system is exactly like a water filtering system. You know the ones that that filter out the impurities and leave you with wonderfully pure drinking water?
Except sugarmakers use the idea in reverse. We filter out the “impurities” (aka the sugars in the sap) and keep them. That’s what we boil down to make syrup. But after the sap has run through the ro system, we can spend a lot less time, energy, and fuel to boil it. And we’re left with pure, cool permeate… Maple Water.