Cooking with the metric system

If these basic units are too big or too small for a particular use, then they can be modified by adding a prefix. For example, "kilo" means 1000 times bigger. A kilogram is 1000 grams, and a kilometer 1000 meters. Here is a table of the prefixes your are most likely to encounter in the kitchen.

Prefix	Symbol	Value	Meaning
kilo	k	1000	A thousand times bigger
deci	d	0.1	Ten times smaller
centi	c	0.01	A hundred times smaller
milli	m	0.001	A thousand times smaller

Combining the three basic units for length (meter), weight (gram) and volume (liter) with the prefixes listed above lets us create the following table of units that we will be using for cooking.

Unit (Symbol)	Quantity	Examples	Uses
milliliter (ml)	Smaller volumes	About the volume of a kidney bean	For measuring most liquids. Not used very often for non-liquids. For quantities larger than about 1000 ml, the liter is normally used.
liter (l)	Large volumes	Slightly more than 1 quart	For measuring larger amounts of liquids or the volume of pots, mixing bowls, etc. Liters are not usually used for measuring dry ingredients. Note that one liter is the same as 1000 ml.
gram (g)	Smaller weights	About the weight of a kidney bean	For measuring the majority of non-liquid ingredients, including flour, sugar, meats, cheeses, butter, etc. For quantities larger than 1000 g, the kilogram is usually used.
kilogram (kg)	Large weights	A bunch of grapes or a large loaf of bread	For measuring larger quantities of non-liquid ingredients, including meats, fruits, and vegetables. Note that 1 kg is the same as 1000 g.
centimeter (cm)	Length	About the width of the nail on your little finger	Any time a traditional American recipe gives something in inches, the metric recipe will probably specify centimeters.
millimeter (mm)	Length	About the thickness of uncooked angel hair pasta	In the kitchen, millimeters are most likely to be used for measuring very small lengths. Note that 10 mm are the same as 1 cm.

It comes in handy to know that 1 liter of water weighs 1 kg, and would exactly fill a cube 10 cm on a side. Similarly, 1 ml of water weighs 1 g, and would exactly fill a cube 1 cm on a side.

Temperature

Temperature in the metric system is usually measured in degrees Celsius (°C). This is the one quantity that many American cooks may need to know in customary units (°F), since most ovens in the U.S. don't have a Celsius scale. Here is a table with some common temperatures in °C.

Temperature	Description
0° C	Water freezes
21° C	Room temperature
30° C	Good beach weather
37° C	Body temperature
100° C	Water boils
200° C	A hot oven

The following converter (below) will convert back and forth between °C and °F. This may be useful, for example, to set your oven if it doesn't have a Celsius scale. Just enter a number in either field, then click outside the text box.

Equipment

Measuring liquids in milliliters is easy. Every liquid measuring cup I've ever seen always has a metric scale on at least one side. In the picture, from left to right, 250 ml, 1 l, and 500 ml.

A good scale that measures in grams and/or kilograms is the one tool that a traditional kitchen may not have. A cheap mechanical scale will work fine, but I prefer an electronic one. If you buy a new scale, pick a model with a large enough platform to comfortably hold a large mixing bowl, and one with a high enough range for the largest things you are likely to cook. Metric recipes routinely specify quantities of non-liquid ingredients by weight, not volume, so you may find yourself using a scale more often than measuring cups.

It's often convenient to measure ingredients directly into a mixing bowl. As an example, imagine I'm going to bake a cake. I would place my mixing bowl directly on the scale (as shown), and hit the "tare" button to zero the scale. I spoon in the required amount of flour, then hit the "tare" button again. Now I spoon in the required amount of sugar. I continue hitting "tare" and adding ingredients until I'm done. Liquids would be measured by the ml in measuring cups, and small quantities like salt may be measured by the ml in spoons (shown below.)

Measuring by weight has a few advantages:

• Weight is more accurate than volume, since it isn't affected by how well packed or sifted, finely or coarsely chopped, etc. the ingredient is,
• It's quicker and simpler. By measuring directly into the mixing bowl, there are no measuring cups to level off, no messes from leveling off measuring cups, less need for sifting, and no dirty measuring cups to wash,
• Recipes can specify any weight, without being restricted to the specific sizes of measuring cups available. There is no more need for oddball measures like "one cup minus two tablespoons" as is seen in some recipes.

Here are a few other handy items that most kitchens already have lying around. American measuring teaspoons and tablespoons are very nearly 5 ml and 15 ml, respectively. Meat and candy thermometers typically include both Fahrenheit and Celsius scales. A ruler or tape measure including millimeters and centimeters may also come in handy.

Examples

Now that you've been introduced to the basics of metric cooking, now might be a good time to give it a try. Feel free to browse the example recipes listed in the left side bar of this page if you don't already have another metric recipe in mind.