Here's What You Can Substitute For Capers
Capers are one of those small additions of seasoning to many meals that no one notices, though they would have a strong effect on the flavor of a dish if they were missing. However, due to allergies or availability, or the flavor simply being too strong, sometimes a substitute is needed.
What are capers? Capers are a small fruit from a low-growing bush native to the Mediterranean that are picked before they ripen. They are a dark green and about the size of a pea or an olive. The taste is best described as lemony, tangy, and briny, the result of them being soaked in brine, which is one of the most common methods of preparation (via The Kitchen Revival).
One of the best substitutes for capers is one you might have on hand anyway — green olives. However, green olives are substantially larger than capers, so it is recommended to only use half the number of olives required by your recipe. For example, if you need four capers, use two olives. To prepare them, cut the olives into small pieces and add them to your cooking as you otherwise would. The taste of green olives is very similar to capers, and by cutting them up, it is unlikely to be noticed by diners (via Tastessence).
Substitute capers with herbs and spices
Thyme is another potential substitute for capers. It is an herb with a flavor that is similar to capers, and releases the flavor into food gradually. As a result, it is recommended that the thyme be added at the beginning of the cooking process to ensure the flavor has time to blend with the other ingredients in your recipe. When adding them, use the leaves alone or with the stem, whichever is preferred. If you don't have fresh thyme, ground or dried thyme will taste the same.
Dill pickles can also be a caper substitute in sauces and salads. The pickles have a blend of sweet and sour and lack the strong bitter taste of capers, so they won't taste the same, but will give your dish a similar kick (via Cuisine Vault).
The most visually similar substitute is green peppercorns. However, to use them as a successful substitute, it is necessary to brine them. To do this, soak the peppercorns in lemon, turmeric powder, and salt for a few hours (via Foodies Story). Alternatively, you can soak them in pickle juice for a similar effect. The taste won't be the same, but it will be in the same flavor family.