I don't know why it's not sticking for you now... so many variables. I haven't really tried any changes at all since I hit on my solution, so I can't suggest what else to try. I can break it whenever I need to and have good results; anywhere from an hour after coating to three or four days.
It's a deck oven. I warm it to 150'C/300'F and turn it off, then leave the trays for about twenty minutes or so. Sometimes the corners get a bit bubbly, but they settle down once they come out.
Well, it doesn't really spread at all on aluminum foil so I pour it onto the lined sheet pans and just let it sit in a 150'C oven and it self spreads and levels. That's my bottle neck now--the oven only holds the four pans. I think with the silpats I'll be able to spread better than I can on the aluminum foil. If not, I'll be stuck at my current batch size. I also have a teflon rolling pin on the way that should make things easy... I hope; kinda winging it a lot of the time.
I'm glad you like the look of it. I think that picture is a little under 1/4" (it's about 5mm), but the added chocolate I'm doing now probably puts it at 7mm, so a bit over 1/4", though the thickness of the toffee is the same.
Yes, brushing both sides. Honestly, it might speed up softening, but I don't know; I've never kept any past about 10 days. I suspect that it wouldn't, though, since I think the seizing chocolate binds most of that water away from the toffee.
I do about 5.5kg of finished toffee, which is maybe a nine pound batch of actual toffee, I think... I'm home today so I don't have my recipe handy. I'm working on aluminum foil at the moment, but next week I should finally get my silpats in (shipping to Brazil is sloooooow), which will hopefully let me do twice as much (I think I can fit thirty pounds in my large pot), so I can move to doing it every other week and free up some time for truffles, which I can't keep up on. I don't score... no particular reason, I just hadn't thought of it. Maybe I will next week, but like you implied, it might be too hard to flip the sheets.
I wish I could think about a fire kettle, but the shop isn't mine, and the owner won't even get more scoops. I hope to be ready to open my own place in a year or so, depending on capital, but I'll be opening small and growing slowly, so maybe in 5 years. Heh.
Yes, that's Celsius. A bit warm, but I like a longer crystallization time, since once it leaves my kitchen, I have little control of how it's abused.
I do coat both sides (humidity is a constant battle, and it really extends the shelf life), first side as thin as possible, the second side about double that, with crushed almonds in the second side. This is mine if you want to see, though because of feedback we've started doing the chocolate a bit thicker than this picture.
