Chill in the fridge until ready to serve. If you used parchment, you should be able to lift it right out onto a cutting board before dividing into 9 even squares (or 16, depending on your preferences!). *Be sure to press your knife down hard to break through that delicious shortbread!
You can open it up and stick a straw in it to taste it every couple days to tell when it’s done, but I noticed that it always tasted sweeter after being in the fridge so I stopped doing that and just try to keep to a schedule (+/- a day or two). When you procure a scoby ...