It's not the potable antifreeze
per se. I would bet folding money
that too little was used, it fermented, and the sturdy foam is bacteria and yeast.
a. You MUST use 35% PG.
b. It's best if you get it out as soon as we are above freezing.
c. There should be NONE in the tanks
, only in the lines (dry the tanks).
But yeah, if you dilute the PG, even with water in the lines, and leave it there until July, you will get Boones Farm. ANY antifreeze
will do this, including EG and alcohol. I've seen engine
AF do this if not run often enough to cook it and with an open cap.