Ok just a couple of things that I have discovered along the way. BTW I too use veggie rennent, so no I don't think that is the problem. Store bought milk because of the processing and sometimes the "watering down" of the milk, never seems to give a good curd. If I use this milk, I have found that I need to strain the curd through a cloth first before I transfer into my baskets, otherwise the curd is so small that they flow straight through the baskets and down the sink. I then leave them drain for probably 1 hour before I attempt the first turn. Check out the recipe exchange page, and fetta #4. That will show you my methods. If I don't strain first through cheesecloth, I lose the entire batch. I don't get the yield that I normally do, but atleast it is not a complete loss.
You can also try adding some calcium to the milk, at the recommended rate. This is supposed to help with curd formation, especially in store/processed milks.
I do all this at the sink, so that it is easy to clean, and the whey can just flow into the sink to start with before I transfer it to a draining tray.
We used to keep goats, but not at the moment. Two things that are most important, proper fencing and facilities, and don't over stock.
So what goats are you looking at getting?