Delia goes metric

Delia Smith’s new book, “How to cheat at cooking”, was published on 15 February, and it is ALL METRIC! Not an ounce, pint, cup or Fahrenheit is to be found between the covers of this latest volume, targeted as it is at busy people who like cooking but don’t have time for elaborate preparation.

It is 5 years since the doyenne of tv cooks last published, and in the intervening period, Delia (or more probably her publisher) appears to have accepted that imperial conversions of every metric ingredient are no longer necessary or desirable. The only arguably non-metric measures given are teaspoons and tablespoons, but as these are now standardised at 5 ml and 15 ml respectively, this is perhaps forgivable. So, well done, Delia! (Examples of her recipes can be seen at this link).

Whether to give recipes in dual metric/imperial units (and if so, which should be primary) has been a difficult issue for publishers for many years. The argument used to be that older cooks would not understand grams and millilitres (obviously, anybody over 50 is unable to learn anything new) and in any case their kitchen scales would be imperial. Then it was argued that even younger people, despite doing “home economics” exclusively in metric at school, really prefer to use the same traditional units as their parents and grandparents. Neither argument proved to be valid – but there was a potentially more weighty argument: the American market.

As the British and the Americans (not to mention Australians, Irish and others) share a common language, it is convenient for publishers if they can produce a single edition of a book for sale in all English-speaking markets. Thus even though publishers find it economic to produce cookery books in minority languages like Danish or Slovak (population ca. 5 million in each case), they have used this argument to resist producing metric-only editions for the British/Australian market and US customary editions for the American market. (This is rather like the threadbare arguments used in the recent controversy about separate metric and US customary packaging for the EU and USA markets).

In reality the argument was always somewhat shaky. Leaving aside the separate culinary tastes and traditions of the national populations, European recipes tend to measure liquid ingredients by volume (in ml) but dry ingredients by weight (in grams) whereas American recipes tend to measure both liquid and dry ingredients by volume (hence “cups” of flour). The American pint (473 ml) is of course smaller than the imperial pint (568 ml).
Problems also arise over how to convert. If the starting point is a traditional imperial recipe, do you convert 1 lb to 450 g or round it up to 500 g? Similarly, should a pint be converted to 570 ml, or rounded up to 600 ml – or down to 500 ml? Note that too much rounding can throw out the relative proportions of ingredients – e.g. if you round dry ingredients up and liquid ingredients down, your cake may dry out and burn.

Undoubtedly, the best answer is to forget about imperial/US customary units, re-measure your recipe in the correct proportions and publish it exclusively in metric units. This appears to be what Delia has done. Congratulations!

Many celebrity cooks, women’s magazines and cookery sections of newspapers have actually preceded Delia in going metric-only. Let us hope that, with Delia’s splendid example in mind, the remaining imperial holdouts will also soon fall into line.

Enjoy a healthy Christmas turkey! Roast for 40 minutes per kg at 190 °C

Many families in the UK will roast a turkey on Christmas day. Preparing a traditional Christmas dinner challenges most people as they are cooking much larger quantities of food than normal. As a result thawing and cooking times are much longer than normally experienced. Failure to thaw or roast properly may lead to food poisoning which is one of the worst things that could happen at Christmas.

Food Poisoning Risk

It is a frightening prospect that 20% of food poisoning cases are poultry related and an estimated 10 million turkeys will be prepared for Christmas in the UK. Although most incidences of food poisoning are not reported, 4 000 Britons reported food poisoning in December 2002. Preparing a traditional Christmas dinner challenges most people as they are cooking much larger quantities of food than normal. As a result thawing and cooking times are much longer than normally experienced. Food poisoning is caused by bacteria and may arise from:

  • Inadequately cooked meat due to not thawing the turkey correctly
  • Inadequately cooked meat due to not roasting sufficiently
  • Cross contamination of bacteria from raw meat
  • Failing to chill leftovers that are retained for later use.

Use kg-based Thawing and Roasting Times

The first two problems can be solved by proper calculation of thawing and roasting times. Now that turkeys in the UK are sold in kilograms, the UK Metric Association says it makes sense to give thawing and cooking times in hours and minutes per kilogram respectively. Unfortunately many products and cookery books give guidelines in minutes per lb/450g. Since turkey weights are labelled in kilos, this means that a cook either has to convert with a calculator or re-weigh the turkey in pounds. As turkeys are often too heavy for kitchen scales it is difficult for consumers to reweigh birds unless they use bathroom scales – which is hardly hygienic! Kilogram-based thawing and cooking times are easily worked out from the turkey’s label.

Thawing Times

Thawing times depend on the temperature of the place used to thaw the bird. Thawing in a refrigerator (usually around 4 °C) is recommended, however many fridges are already full around Christmas time. Alternatives are to thaw in a cool room or even room temperature.

  • For thawing in a fridge at 4 °C, UKMA recommends allowing 12 hours per kilo. Thus to thaw an 8 kg turkey allow 4 days.
  • For thawing in a cool room at 15 °C, UKMA recommends 7 hours per kilo; so 56 hours for an 8 kg turkey.
  • For thawing at room temperature at 20 °C, UKMA recommends 2 hours per kilo; so 16 hours for an 8 kg bird.

Obviously your fridge or room may have a different temperature to those listed so you may need to allow more or less time than quoted.

Turkey Hygiene

Other tips for preparing the turkey:

  • Do not wash the turkey – that risks spreading bacteria! – roasting not washing will kill the bacteria.
  • Check the inside cavity for ice crystals at the end of thawing. If ice is still there, you need more time for thawing.
  • Avoid cross-contamination by keeping the raw turkey separate from other foods and dishes.
  • Avoid cross-contamination by carefully washing hands, knives, boards and utensils that have been in contact with the raw bird.

Roasting Times

For roasting, UKMA recommends roasting for 40 minutes per kg at 190 °C, Gas 5 – thus an 8 kg bird will take 320 minutes (5 hours 20 minutes). Fractions of kilos are also easy to calculate by allowing 10 minutes for each additional ¼ kg, so an 8.25 kg requires 5 hours 30 minutes. Check the meat is cooked by parting the skin between the leg and breast. If it is still a little pink then allow an extra 20 minutes on top of your calculated time. Juices should run clear not pink.

More Tips

Other useful tips for a perfect roast turkey on Christmas Day:

  • Check your oven is large enough if you intend cooking a big bird, and buy a special turkey roasting pan.
  • Turkeys are heavy so take care when lifting in and out of the oven.
  • Smear the breasts with olive oil or softened butter and protect the breast with butter papers or foil. Or, work your hands between the skin and flesh of the breasts and slide in large wedges of soft Brie.
  • For a tasty attractive finish sprinkle the turkey with ground paprika and crushed thyme before cooking.
  • For hygiene reasons, don’t stuff the body cavity. Instead lift the neck flap and press your stuffing up against the wishbone.
  • Never carve a bird straight from the oven. Allow it to stand for at least 20 minutes. It won’t lose heat if you cover it loosely with a foil “tent”. This also allows you to get your roast potatoes nice and crisp.
  • Chill leftover turkey as soon as it is cold and serve within 3 days. If serving hot in a sauce or as a curry, then reheat until piping hot.