How many times can we shut down the evaporator and not effect grade?

[SugarMama]

Well we are already behind this year, work is getting in the way of my syrup operation :( We do batch processing, Last year we would run sap through the evap. (about 150 gallons plus, then we would shut it down, let it cool and fire it up again the next day, I'm wondering how many nights can I shut it down and the fire it back before it changes grade? (This is all fresh sap from yesterday and Today)

Also will drawing it off leaving it cool (its freezing here at night) and then reheating it (to 190) to bottle affect grade?

Thanks

[Maplesapper]

I believe if you boil it and then restart there is minimal grade deterioration vs letting raw sap sit for days on end.
Our experience has been better boiling then sitting and reboiling vs storing raw sap and boiling a complete batch.
Typically we batch boil on a 2x4 pan, 100-150 gallons of sap is a standard good run for us.
Just my two cents