I'm going to try bottling (or canning as all the US websites say) tomato and apples. As far as I can tell I just make the sauce bung it in the jars and whack it in the pressure cooker for about 10 mins with water half way up. If it goes off how will I know? Will it be mouldy and smelly or could it appear to be ok and in fact riddled with botulism? And what other pitfalls are there? All the info I can find is american and just tells me to refer to the instructions of my presure canner.