Yeast starter

I was going to brew tomorrow night so I got my starter going last night. I won’t be able to brew now so what should I do with the starter in order to use it this weekend instead?

I usually have my starter 3-4 days before brewing. I think it should be fine.  I’m sure I’ll be corrected if I’m wrong, but once the starter is finished, if you’re not yet ready to brew, just put it in the fridge until ready.  Bring it out, let it warm to room temp, decant, and pitch.

Wait till it ferments out, then put it in the refrigerator. You will be fine. If you have to wait until the next weekend (1st weekend of december) you may need to put it in some fresh wort to get everything going again.

Just out of curiosity, how long would it be viable in the fridge before I had to throw it out?

Months likely.

at some point (weeks) you would want to build another starter from it but yeah it’ll be viable to some extent for a very long time.

When using yeast nutrient, when do you add and how much?

I add a pinch (maybe 1/8 tsp.) to my starter wort.

OK to boil?

Yes.