This reminds me - my current Weiss has fermented out and finished at about 3.7% instead of the ~5% it was supposed to be. I knew it was going to happen from the OG when I pitched the yeast but thought it might work out as a good quaffing beer.
However, now it’s finished fermenting, it tastes great but does really need an extra percent or two of alcohol content - I’m interested to know if I can I just pour a few hundred grams of table sugar into the fermenter and let the yeast wake up and get on with it? Would there be an infection risk from doing so? And is this sacrilege and hackery?