Cooking times for meat are not proportional to the weight. They are closer to being proportional to the weight raised to the power 2-3, but most cooks don't want to do complicated calculations. What that means is that any cooking chart has to provide an approximation which is good over the typical range of weights used.
A general question, and an offerHello everyone, I've been lurking and, occasionally, contributing to this newsgroup for some time now. As some of you may know, I'm an Englishman now...
For example, say you are given a time of 30mins-lb+30 minutes then for joints in the range 1 to 6 pounds:
Beijing 99danw Thanks for the words of advice, though I read the more helpful ones once I'd got back. A few thoughts: The food was a lot more to Western tastes than I thought...
Weight 60*(weight**0.67) 30*weight+30 45*weight 1 60 60 45 2 95 90 90 3 125 120 135 4 151 150 180 5 176 180 225 6 199 210 270
This is why the +xx minutes format tends to be a better approximation, but it will still be too short for very large ones. The simple x minutes per pound is only right round a very short range of times.
It is common to start off at a high temperature for the initial fixed period and then a lower temperature for the remainder. This has the advantage of browning the outside of the meat (for flavour), but also ensures more even heat transmission through the joint as the initial wave of heat spreads inwards.
You should also be sure to always let the meat rest in a warm place after cooking. Usually about 1-2 hour is the recommended time.
Other factors which also affect the cooking time include: the initial temperature of the meat, the shape of the joint, the distribution of temperature in the oven. It is worth getting a digital probe thermometer so you can double check how quickly the meat is actually cooking.
Ideally you want the inside of the meat to be cooked as evenly as possible which means using as low an oven temperature as you can and starting with the meat at room temperature. Some of Heston Blumenthal's recipes for roasting meat involve oven temperatures around 75-80C for several hours which results in very even cooking and low moisture loss.
