Thanks for all the help on my last Q.

I have a new one.

Since I am still experimenting, I am making small batches of candy 1/2  - 1 lbs sugar.

I bring my mixture up to hard or soft crack and then let it cool to 250 F. Add in some citric and flavour and then pour. 

With a small batch, the time before it hardens is very short. If I add in powdered citric, it tastes fine and hardens perfectly....

But if I need to reheat it... even on the lowest flame it burns immediately. 

I have tried removing it at my proper temp and putting the pot immediately on a double boiler. And let it slowly go down to 250 F and that has helped a lot.

I have also tried adding a little water to my citric. It poured into molds perfectly but never quite hardened.

Here is my questions:

What is the ideal temp to add citric and what is the burn temp?

What is the ideal temp to add malic and what is the burn temp?

When I EVENTUALLY graduate to doing bigger batches will it give me a long working time? 

I plan to try pulling sugar in a month or two, what is a good batch size to start with?

And  also.... How do you keep the sugar from sticking to marble? I tried an oiled slab and it took a few hours of chiseling to remove it!

yeah the extra water killed the pathway for it to harden which is why it's better not to add color after getting it to temp so said susan notter and that tidbit sure worked for me -- marble is great for chocolate not sugar -- a silicone mat or was it some other thing -- trying to remember -- i think i got that answer (that i obviously can't remember)  on chicago mold school -- (was it plastic wrap on top of the silicone? can't remember) beyond that i don't know the answers but this is a great website/resource for you:

http://chicagomoldschool.com/

also maybe on the forums at egullet.org -- there might be some great sugar info and there's usually some pastry chefs over there who deal with it more constantly