How many of your favorite recipes contain a touch of lemon? The number may surprise you. Perhaps it's lemon zest instead of lemon juice. Either way, the balance of sweet with sour accentuates the whole flavor package in a dish.

Lemons, limes, grapefruit, calamansi, and pomelo provide predominately sour flavor notes in the citrus band. This newsletter will explore why a sour note makes sweet notes happier.

Imagine you've been served a weak glass of lemonade. Something is missing. Without adequate contrast, a balance of opposite flavors, the whole flavor experience is flat. In the case of the weak lemonade, there's not enough lemon juice. When the amount of lemon juice more equally matches the amount of sweetener in lemonade, the drink offers full flavor and greater thirst quenching refreshment on a hot day.

But the sweet and sour balance is not limited to lemonade. Remember the final touch to homemade apple pie? It's a little lemon juice drizzled on top of the sliced apples piled high in that unbaked pie shell moments before the top crust is applied and the pie is popped into the oven.

Bean soups usually include lemon juice. The mellow sweetness of  cooked beans and onions is brought into focus with lemon juice as a minor, but important, ingredient in the recipe. You might even find a slice of lemon or lime in the bottom of a bowl of Indian Red Lentil Soup.

For years, the Italians have made Gremolata, a simple seasoning mixture of minced, fresh, Italian Parsley, garlic, and lemon zest. Though the seasoning is often used for meat dishes, it enhances pasta, beans, and salads. Changing out the parsley for mint leaves makes a nice variation. Add olive oil and it's a dressing.

In the end, one of the best examples of flavor enhancement from lemons is the addition of lemon zest. Grating the rind of a lemon creates lemon zest. Fresh blueberries certainly possess their own appealing flavor, but it's subtle and mild. Adding a little lemon zest to the smoothie awakens all the nuances of blueberry flavor that would otherwise remain hidden.

Treat yourself and those at your table to some simple gourmet eating by adding lemon juice or zest as a natural flavor enhancer—and make that organic if possible, to avoid the considerable pesticides used in the growing of lemons.