Understanding the Standard Tablespoon
The fundamental volume of a tablespoon is determined by the measurement system you are using, not by the density or type of liquid. For culinary purposes, the key distinction is between the international metric system and regional variations like the US Customary system. For precision, especially when following recipes from other countries, it is crucial to know which standard is in use.
The International Standard: Exactly 15 mL
The most widely recognized standard for a tablespoon is the international metric system, which defines it as exactly 15 milliliters. This standard is used in most countries and is the basis for nutritional labeling in the US, making it a reliable reference point. This volume is straightforward and used by most professional chefs and bakers when metric measurements are called for.
The US Customary Tablespoon: A Slight Difference
For those cooking with US Customary measurements, a tablespoon is technically defined as 14.7868 mL, but this is almost always rounded up to 15 mL for practical kitchen use. The difference of just over 0.2 mL is negligible for home cooks but worth noting for scientific applications. US measuring spoons and recipes are based on this customary system, which is also equivalent to half a US fluid ounce.
Other Regional Variations
While the metric and US systems are the most common, some regions have unique standards. A notable example is Australia, where a metric tablespoon is defined as 20 mL. This is a more significant difference and can impact the outcome of a recipe if not accounted for. Using Australian recipes requires careful conversion or the use of Australian-standard measuring spoons to ensure accuracy.
Why the Liquid Doesn't Matter (For Volume)
Extra virgin olive oil, like other liquids, will occupy the same volume in a measuring spoon as water or any other liquid. While it has a different density than water—floating on top because it's lighter—this affects its weight, not its volume. Therefore, 15 mL of extra virgin olive oil takes up the same space as 15 mL of water, but it will weigh slightly less. The volume-based conversion holds true regardless of the liquid.
The Importance of Using Correct Measuring Tools
Accurate measurements are the foundation of successful cooking and baking. Relying on cutlery spoons from your silverware drawer can lead to inconsistent results, as their volume can vary widely. A calibrated measuring spoon set, typically made of stainless steel or durable plastic, ensures consistency and accuracy every time.
List of Conversion Equivalents
- 1 tablespoon = 3 teaspoons
- 2 tablespoons = 1 fluid ounce (US)
- 4 tablespoons = 1/4 cup
- 16 tablespoons = 1 cup
- 15 mL = 1 international metric tablespoon
Table: US Customary vs. International Metric Conversions
| Measurement | US Customary (approximate) | International Metric (exact) |
|---|---|---|
| 1 Teaspoon (tsp) | 4.93 mL | 5 mL |
| 1 Tablespoon (tbsp) | 14.79 mL | 15 mL |
| 1 Fluid Ounce (fl oz) | 29.57 mL | 30 mL (approx.) |
| 1 Cup | 236.59 mL | 250 mL (approx.) |
How to Avoid Measurement Errors
To ensure your recipes turn out perfectly, especially when converting units, consider these tips:
- Use a standardized measuring spoon set: Rely on a dedicated set of measuring spoons rather than cutlery to guarantee accurate volume measurements. Look for sets that clearly label both the US customary and metric units.
- Stick to one system: When possible, follow a recipe using a single measurement system. If the recipe is in metric, use metric measuring spoons and a kitchen scale for dry ingredients. If it's US Customary, use US measuring cups and spoons.
- Level off your measurements: For precise volume, especially with thicker liquids like extra virgin olive oil, fill the measuring spoon to the top and use a straight-edged utensil to scrape off any excess, ensuring a perfectly level measure.
- Embrace the metric system: If you frequently use recipes from around the world, investing in a kitchen scale that can measure in grams and a metric measuring set is a wise decision. The metric system is consistent and simplifies conversions.
Conclusion
For most culinary applications, one tablespoon of extra virgin olive oil is equivalent to 15 mL, aligning with both the international metric standard and the widely accepted rounded figure for the US Customary system. However, regional differences, like the 20 mL Australian tablespoon, do exist and should be noted when using international recipes. The key to accuracy is using proper measuring tools, as the volume remains consistent for all liquids, despite differences in density. By using standardized measuring spoons and being mindful of regional variations, you can ensure your cooking and baking are precise and produce delicious results every time.
For further reading on culinary measurements and conversions, a reliable resource can be found at the Exploratorium's Measurement Equivalents page.
Frequently Asked Questions
What is the difference between an international metric tablespoon and a US customary tablespoon in mL?
An international metric tablespoon is exactly 15 mL, while a US customary tablespoon is approximately 14.79 mL. The small difference is generally considered insignificant for home cooking and baking.
Does the density of extra virgin olive oil affect the conversion from tablespoon to mL?
No, the density of extra virgin olive oil does not affect the volume conversion from tablespoon to mL. Volume measures space, while density affects weight. One tablespoon of any liquid will occupy the same volume, although its weight will vary.
Is an Australian tablespoon different in size?
Yes, an Australian metric tablespoon is larger, measuring 20 mL, compared to the international metric standard of 15 mL.
Why is it important to use a proper measuring spoon instead of a regular spoon?
Regular cutlery spoons, unlike standardized measuring spoons, vary widely in their capacity and are not a reliable measure of volume. Using a proper, calibrated measuring spoon ensures accuracy and consistency in your recipes.
How many mL are in a teaspoon of olive oil?
There are 5 mL in one international metric teaspoon. In the US customary system, a teaspoon is 4.93 mL, though 5 mL is the commonly used rounded figure.
What are 2 tablespoons of extra virgin olive oil in mL?
Two tablespoons of extra virgin olive oil are equivalent to 30 mL under the international metric standard.
If a recipe calls for 1 tablespoon and doesn't specify, what should I assume?
If a recipe doesn't specify, it is safest to assume the international standard of 15 mL, as it is the most common and is used for nutritional labeling in many countries, including the US. Using a standard 15 mL measuring spoon is the most reliable approach.
