Key limes are a small, tart, green citrus fruit that are a popular ingredient in many dishes and beverages. When juiced, key limes provide a bright, acidic juice that adds wonderful flavor to things like margaritas, ceviches, and Key lime pie. But how much juice can you expect to extract from a single key lime?
What is a Key Lime?
The key lime (Citrus aurantifolia) is a small citrus fruit that is typically 1-2 inches in diameter. It is greenish-yellow when ripe and has a higher acidity and stronger aroma than the more common Persian lime. Key limes originated in Southeast Asia and were later introduced to the Florida Keys in the 1500s. The name “Key” refers to the Florida Keys where they are heavily cultivated.
Key limes thrive in tropical and subtropical climates. They have a thin, aromatic skin and their flesh ranges from light yellow to green in color. Inside each segment of a key lime you’ll find small, oval-shaped seeds. Key limes tend to be more tart, acidic, and flavorful compared to conventional limes.
Average Juice Yield of a Key Lime
On average, one medium sized key lime (about 42g or 1.5oz) will produce approximately:
- 1-2 tablespoons (15-30ml) of fresh key lime juice
- Around 1 fluid ounce (30ml) of juice
This amount can vary based on the size and ripeness of the lime. Larger, ripe key limes tend to produce a bit more juice compared to smaller, underripe ones.
Key Lime Juice Yields Based on Lime Size
As a general guideline, here is how much juice you can expect from key limes of different sizes:
| Key Lime Size | Average Juice Yield |
|---|---|
| Small (1-1.25 inches diameter) | 0.5-1 tablespoon (7-15ml) |
| Medium (1.25-1.5 inches diameter) | 1-2 tablespoons (15-30ml) |
| Large (1.5-2 inches diameter) | 2-3 tablespoons (30-45ml) |
As you can see, juice yield ranges from around 0.5 tablespoon (7ml) for a small lime up to about 3 tablespoons (45ml) for a very large, juicy key lime.
Tips for Getting the Most Juice Out of Key Limes
Here are some tips to help you maximize the amount of juice you can get out of fresh key limes:
Select ripe, fresh key limes
Always start with fresh, ripe key limes. They should feel firm yet light for their size, with a thin, smooth skin. Soft, shriveled limes will produce less juice.
Roll the limes
Before juicing, roll the limes firmly on the counter while applying light pressure. This helps break down some of the membranes inside and release more juice.
Microwave briefly
You can zap whole key limes in the microwave for 10-15 seconds on high. This helps loosen up the juice inside. Let them cool before slicing open.
Slice in half and juice
After preparing the limes, slice them lengthwise and juice them using either a citrus juicer, reamer, or hand squeezer. A citrus press will be most efficient.
Squeeze out the pulp
After juicing, take the leftover lime halves and squeeze by hand over a bowl to extract any remaining juice and pulp.
Strain for maximum yield
Pour the collected juice through a fine mesh strainer or cheesecloth to separate all the liquid from the solids.
Juice limes when needed
For best flavor and yield, juice key limes right before using. Juice doesn’t stay fresh long once exposed to air.
How Key Lime Juice is Used
The tart, vibrant flavor of key lime juice adds a wonderful citrus kick to both sweet and savory recipes. Here are some of the most popular uses for key lime juice:
Key Lime Pie
This iconic dessert is made by filling a prepared graham cracker or pastry crust with a rich, creamy key lime custard filling made with key lime juice, sweetened condensed milk, and egg yolks. It’s topped with whipped cream before serving.
Margaritas and Cocktails
Key lime juice is excellent for making margaritas, daiquiris, and vodka or gin cocktails. The lime adds bright acidity to balance sweetness and alcohol.
Marinades and Dressings
Add some key lime juice to make tangy citrus marinades for chicken, fish, or beef. It also livens up salad dressings and dips.
Salsas and Relishes
For pico de gallo, guacamole, and fruit or veggie relishes, key lime juice infuses dishes with refreshing lime zest.
Seafood Dishes
Key lime juice is excellent squeezed over raw oysters, clams, and ceviche. It “cooks” the seafood while adding tons of flavor.
Baked Goods
Add a teaspoon or two of lime juice to lend a citrus tang to cakes, muffins, and cookie recipes. It helps balance sweetness.
Storing Key Lime Juice
To retain the best flavor and quality, here are some key lime juice storage tips:
- Refrigerate for up to 5 days – Store fresh squeezed juice in an airtight container in the fridge.
- Freeze for 3-4 months – For longer term storage, freeze juice in ice cube trays or muffin tins.
- Use glass or plastic – Avoid storing in metal containers, which can impart a metallic taste.
- Add acid – Adding a bit of lemon juice helps stabilize and preserve fresh lime juice.
- Keep air out – Minimize air exposure by sealing containers tightly.
Buying Bottled Key Lime Juice
While fresh squeezed is best, you can also find bottled key lime juice for sale in the refrigerated sections of many grocery stores. Here’s what to look for when purchasing bottled varieties:
- 100% Key Lime Juice – Avoid blends diluted with water, sweeteners, etc.
- No added ingredients – Get just straight pressed key lime juice with no additives.
- Refrigerated – Choose chilled vs shelf stable bottles for freshest flavor.
- Expiration date – Check dates and use within a few weeks of opening.
- Sealed container – Once opened, reseal tightly and refrigerate.
Bottled juice lacks the freshness of squeezed, but it’s definitely more convenient. Shake containers before using as lime oil may separate on top during storage.
Key Lime Juice Substitutes
If you don’t have key limes, these make solid stand-in options:
Persian Lime Juice
Persian limes are larger and less acidic than key limes, but their juice can still be used 1:1 in any recipe calling for key lime juice. Expect a slightly milder citrus flavor.
Lemon Juice
Lemon juice doesn’t have the same tropical, aromatic qualities of key lime juice, but it can work well as a substitute in dressings, marinades, and cocktails. Use a 1:1 ratio.
Regular Lime Juice
Standard green limes are another decent substitute in sauces, ceviches, and the like. The juice has a near identical pH and acidity to key limes.
Bottled Juice Blends
Many grocery stores sell “Key Lime Juice Blend” products that combine lime, lemon, and sometimes Persian lime juices. These work well for cooking applications.
Frequently Asked Questions
Why are key limes so small?
Key limes are naturally a small, compact variety of citrus. Their small size could be due to adaptation to the tropical climate of Southeast Asia where they originated. The dwarf tree size also made them handy to grow in small spaces.
Are key limes and Persian limes the same?
No, key limes and Persian limes are two different fruits. Key limes are smaller, seedier, and more acidic. Persian limes (also called Tahitian limes) are larger and less tart.
Can you use regular lime juice instead of key lime?
Yes, you can substitute regular lime juice in most recipes calling for key lime juice. The flavor won’t be an exact match but the juice acidity is very similar.
Why is key lime pie green not yellow?
Authentic key lime pie gets its greenish tint from using real key lime juice. The green color comes from the natural aromatic oil in key lime peel that tints the juice. Some modern pies use artificial coloring.
Do key limes go bad faster than regular limes?
Due to their small size, key limes have a slightly shorter shelf life compared to larger Persian limes. Store key limes in the fridge and use within 2-3 weeks for best quality and freshness.
Conclusion
When juicing key limes, you can expect an average yield of around 1-2 tablespoons (15-30ml) of fresh lime juice per lime. Exact amounts vary based on ripeness and size. For maximum juice extraction, select fresh, ripe key limes and use a citrus juicer or reamer. Add the vibrant, tangy juice to cocktails, marinades, pie filling, and more. Store fresh key lime juice for 3-5 days refrigerated or freeze for longer duration. Bottled juice makes a convenient substitute.
