I've seen the terms 'dry aged' and 'wet aged' on steak menus. What does this mean? When beef is fresh the flavour is mild, but the meat can be tough because the muscles haven't had a chance to relax. Ageing the meat serves to tenderise it. Only the best, most marbled beef is aged. It used to be done only by a process called dry-ageing - hanging the sides of beef in temperature- and humidity-controlled refrigerators. This gets rid of excess moisture, allowing the flavours to intensify (giving it a 'beefier' taste) and letting the natural enzymes break down the protein structure to tenderise the meat. The meat is aged for about 14 days; top steakhouses age it for three weeks or longer. Because the meat shrinks and there is a lot of waste (the beef that is exposed to the air needs to be sliced off and discarded), dry-aged beef is expensive. A more recent development is wet-ageing: the beef is sealed in vacuum-pack bags and refrigerated for about a week. As with dry-aged beef, the enzymes break down the protein structure, resulting in more tender meat, but because there is no loss of fluid, the flavours don't become more concentrated. Most places prefer to age their beef this way because it is much easier and has less wastage. When folding whipped egg whites into the yolk and flour mixture for a sponge cake, there are parts that do not incorporate into the mixture and I end up with spots of egg white in the baked cake. If I fold for too long, however, the egg white turns into liquid. Should I just mix more vigorously? If you're incorporating whipped egg whites into a sponge cake, you must take care not to mix it too much or the entire mixture might deflate. When you put the cake in the oven it won't rise, and the end result will be tough and flat. You shouldn't have this problem if you don't overwhip the whites. Some recipes have you whip the whites to stiff peaks, but soft to medium peaks are easier to incorporate because they're about the same consistency as the rest of the mixture. If you do find that there are still 'lumps' of whites that won't fold in, use a spatula to flatten them against the side of the bowl. This will deflate them slightly (better than deflating the entire mixture) and they'll be easier to mix in.