So I did lots of reading and research on this last year... the scenarios I came back with are this.
1. a slow freeze after a day of above freezing temps will leave a thin later of ice that is close to sugar free... I dump it... people on this site have tested it so I feel comfortable doing this.
2. a hard freeze will get everything sold.
3. in between.... frozen with a core of unfrozen... I do think due to the way it freezes that the core is concentrated. Sometimes I chuck it, most times I leave it and let the next day melt it. I look at it as a way to keep the new sap nice and cold. Totally frozen chunks also get saved and put in the tank to help keep it cold.
My biggest issue is keeping stuff cold since I boil on weekends mostly.
The whole question really only applies to us small timers... anyone bigger is often running tubing and ice is a non-issue with that setup. They also have RO which makes the who sugar content issue moot.
31 Taps in 2011 with buckets, Barrel evap
45+ Taps for 2012 with buckets, 2x5 Dryer Arch with steel pans ! 8x11 Sugar Shack, Dump Stations,
60 Taps for 2013- Insulated Dryer arch, AUF,
2014 watched from sidelines...
70 Taps for 2015 - dryer arch, new 2x5 divided pan from Smokey Lake with a float box !
70 Taps for 2016 - added a preheater and new grates for the Dryerator.
80 Taps for 2018 - Dryer arch got new front and door