I'm currently making/baking various gifts for people for christmas and this years big thing (for me at least) is chocolate bars. I'll go to the store and get three bars of cheap (like 50p for a large bar cheap) dar, milk and white chocolate. When I get home I'l melt one in my mini chocolate fondue and do a few different designs (initials/hearts etc) and then wipe the pan out before melting another bar down to pour own the top, leaving a bar with a design on the bottom (or top once it's set and been turned over); all of this is done on greaseproof paper.
The problem is that at first when I took a bar out of the fridge, even after it has set, it started to melt again really, really, quickly. This went away and I thought it could be because of molten chocolate lingering in the centre of the bar. But after reading up online I'm now terrified that it'll revert to this because haven't tempered it. Presumably the bars were tempered before I bought them so can I stop worrying or do you need to retemper chocolate each time you melt it?
PS If I do need to retemper it can anyone recommend a good way to do it without a microwave?