on decarb...
when you are making it, you are evaporating the alcohol off, whether with heat or time. if you use heat (a rice cooker, or a hot plate or stove and double boiler...) while that is happening you will notice it sort of boiling. you will see bigger bubbles forming and popping like boiling water. as it gets rid of the alcohol the viscosity or that thicker consistency will get more and more thick. as that happens the alcohol is being gotten rid of. you can tell when that is done when the bubbles are not big anymore. you will still have bubbles, but the big ones will stop.
at this point, you will get little bubbles. those bubbles are the stuff decarbing. keep heating till those bubbles stop forming.
so... if you cook off the alcohol and dont continue to decarb and you set it close by, you can watch it over the next days and those little bubbles will happen (no heat at all applied, just happens). it will decard on its own.
you can test this. when you make some, put a small amount in something and watch it. if you decarb however you want before the alcohol step, you can watch and note that you will still get some tiny bubbles, because those methods of decarb dont do as full of a job as this
anyway, you are decarbed when the tiny bubbles stop.