MPC: MEASUREMENTS AND MEASURES

The Metric System

The metric measure refers to measurement that is based on the metre and kilograms. The metric system is based upon the decimal system. The metric unit used in the kitchen are:

1. Millilitre (ml) and litres (l = 1000ml) for volume measurements, instead of teaspoons, cups and quarts;
2. Grams (g) and Kilograms (kg = 1000g) for weights instead of pounds and ounces;
3. Millimetres (mm) and centimetres (1cm = 10mm) for linear measurements instead of inches;
4. Degree Celsius (°C) for temperature instead of degrees Fahrenheit (°F).

Thus the abbreviations:

g – gram

Kg -Kilogramme

dl – decilitre

l = litre

mm = millimetre

cm = centimetre

°C = °Celsius (centigrade)

°F = °Fahrenheit

Methods used to convert Measurements to Metric

There are two ways of converting recipes measurements to metric. One is the method of “soft” conversion, in which the actual measurement is mathematically converted to metric and rounded off to the nearest round figure. This method is not so practical, however, because you might arrive at a quantity that is not easily measured in the new metric cups and spoons. Also, many goods will be pre-packaged in unit\s of halflitres, or litre or half-kilograms, and so forth, instead of in units of points, quarts or pounds. The other method used is called “hard or solid” conversion. Most recipes has been readapted to metric, using the most convenient and or standard metric measuring unit that works in the recipe even though it may not be as an exact conversion from other standard measurement.

Metric Measurements for Liquid and Dry Volume

All metric measurements for volume are expressed in millimetres and litres. 30ml = 1 ounce 1l (1000ml) = approximately 1 quart.

Metric measuring equipment comes in the following standard sizes:

1. Measuring Spoons

1 ml (slightly less than ¼ teaspoon)

• 2ml (slightly less than ½ tea spoon)
• 5ml (almost exactly 1 teaspoon )
• 25ml (about 12 /3 table spoons, or 1 teaspoon less than 1/8 cup)

2. Small cups for dry measure

• 50ml (2 teaspoon less than ¼ cup)
• 125ml (1½ teaspoons more than ½ cup)
• 250 ml (1 table spoon more than 1 cup)

3. Large Measuring Cups

• 500ml (0.5L) about 1 2/3 tablespoon more than I pint)
• 1L (1,000ml) about 32/3 tablespoon more than 1 quarters

Solid Conversion (metric weight)

A kilogramme is subdivided into gram and common abbreviations used in recipes are kg for kilogramme and g for gram. There are 1000gms in 1 kilogramme. The table below gives the conversion of ounces into grams. Exact conversions would take us into complicated fractions, so the weights are given to the nearest whole figure in grams.

In the anticipation of converting to metric system, it is suggested that you take 25g as the basic unit, because it is easily multiplied for larger metric quantities – 50, 100, 250, 500 and it provides the foundation for thinking metrically to carry beyond the stage of trying to convert imperial weights into their exact and awkward metric equivalents. It is therefore suggested for example, 100g as an easy alternative to 40z.

To maintain consistency, fluid quantities could also be rounded off in the same way so that ½ pint, for example, becomes 250ml instead of the exact equivalent 284ml. Many recipes are based on the proportions such as “half fat to flour’ or one part fat, and one part flour to 10parts liquid for a thick sauce. These are easily calculated in terms of the unit chosen. Recipes based in the 25g unit fit into the existing equipment found in home and schools, colleges, kitchens and the unit link up with the teaching of mathematics.

Metric Conversion for Liquid (Fluid) Measures

Approximate Quantities of Food to Serve

Appetites differ so much that you must take this into account when estimating. One of the worst disasters that can befall a cook is to run short of food. It is even worse for the guests, especially if they are enjoying what you have cooked. So it is always safer to err on the generous side if you are catering for people you do not know. To give you a guide, the following quantities are the minimum to allow for each person:

Pan Sizes and Linear Measurements

Under the metric system, some baking dishes such as casseroles are marked in litre sizes. Most pan sizes, however, are expressed in centimetres instead of inches. Thus 1 centimetre = 0.4 inches, I inch = 2.5 cm.

Cooking Temperatures The metric cooking temperatures are expressed in degrees Celsius (°C) formerly called degrees centigrade – instead of degrees Fahrenheit (°F). The Celsius system is based on a freezing point 00C and a boiling point of 100°C.

Temperatures No degree Fahrenheit (°F) minus 32 x 5 /9 = degrees Celsius (°C) Example 212°F = 100°C (boiling water)

Temperature for Baking and Roasting

Round the temperature in Celsius to the nearest 10.

For example, if a baking temperature of 325°F is needed, the equivalent in Celsius is 163°C; rounding to the nearest 10 would give 160°C.

Simple Test for Temperature in Local Ovens: Example Swish Oven or Anthill Oven

1. Heat the oven by the method suitable for each particular type of food
2. Place a piece of white paper in the oven for 2 – 3 minutes. If the paper is:

• Black – Oven too hot
• Dark brown – very hot
• Golden brown – Hot
• Light brown – moderately hot
• Light biscuit – Slow