In a batter, the amount and type of flour most influences the quality of the batter. Adding too much flour may result in a tough batter, too little may make the final coating too fragile after frying. The protein in flour helps the batter cling both to the object fried and to itself, for a cohesive covering. The protein also forms the elastic strands of gluten and absorbs fat and moisture. Too much absorption will result in an oily and chewy coating. All-purpose flour, which is a wheat flour with a moderate amount of protein, offers a solid base for a batter when it's well balanced in a recipe.

Several other types of flour work as well as all-purpose flour for making batters. Rice flour batters provide crispier and drier results than their wheat-based counterparts because rice proteins absorb less fat and moisture and do not form gluten. Corn flour offers similar benefits. To reduce the influence of wheat proteins in a batter with all-purpose flour, you can add pure cornstarch to the mix. Chickpea flour creates a nutty and crisp coating for fried foods and has the added benefit of being wheat-free for those with an intolerance. Avoid using root flours, as their starch content will become gelatinous and begin to disintegrate during the beginning of the frying process.

Baking soda serves as a leavening agent in a flour-based batter. The reaction of the baking soda with the liquid in the recipe creates gas bubbles. This release of carbon dioxide gas is responsible for adding the lightness to the final fried product. Adding a small amount of acid, such as lemon juice or buttermilk, to your batter will heighten the reaction. While it may be tempting to replace baking soda with baking powder, do not do so. Baking powder is a combination of baking soda and cream of tartar and is about one-third to one-quarter as strong as the soda.

Whatever recipe for batter you choose to follow, keep in mind several important factors about the preparation. Most batters adhere best to moist foods if the food is first dredged in a dry ingredient. The dry particles stick to the moist food, creating a rough surface for the moist batter to cling to when the food is dipped. Roll the food you intend to fry in seasoned flour, shake it off, and then dip it into the batter. Prepare your batter as close to the moment you start frying as possible, to prevent the gas bubbles caused by the baking soda from leaking out. If much of the air and gas escapes the batter, you will end up with a dense covering on your fried food. Additionally, use cold water for the batter and mix it as little as possible to combine it, to prevent gluten development and too much water absorption.