Rusks must be brittle and completely dried out to be done. They also last for ages this way. One tip on drying is that the thicker the rusk, the longer it takes to dry – that’s obvious I guess. Less obvious is the denser the rusk in terms of ingredients (the more ingredients the more dense), the longer they take to dry. I also tend to let rusks that have moist ingredients like raisins dry for longer. The lowest my new oven goes is 170 degrees so my drying time is less than previously. Bottom line is you have to check after about 4 – 5 hours.
Tip: The rusks are sufficiently dried if, when you press them between your fingers, they feel solid. If they feel at all spongy dry them out some more.
Once you’ve cut the rusks up, here’s how you dry them out:
Place the individual rusks onto a baking tray leaving spaces in between each one. For the recipes on this site you will need two baking trays – at least one of them large sized.
Leave to dry overnight at about 100 – 125 degrees. If you turn up the heat you will burn the edges of the rusks without really drying them out.