Chicken coating can come off when frying due to several reasons, including:

1. **Insufficient Adhesion:** If the chicken is not properly coated with flour or breading before frying, the coating may not adhere well to the surface of the chicken. It's essential to ensure that the chicken is evenly coated with flour or breading and that any excess coating is shaken off before frying.

2. **Moisture on the Chicken:** Excess moisture on the surface of the chicken can prevent the coating from adhering properly. Make sure to pat the chicken dry with paper towels before coating it with flour or breading to remove any excess moisture.

3. **Improper Dredging Technique:** When coating chicken with flour or breading, it's crucial to follow the proper dredging technique. This typically involves dipping the chicken in seasoned flour, then in beaten egg or buttermilk, and finally in breadcrumbs or seasoned flour again. Each layer helps the coating adhere to the chicken.

4. **Oil Temperature:** If the oil temperature is too low, the coating may not crisp up properly, causing it to become soggy and detach from the chicken. Conversely, if the oil temperature is too high, the coating may brown too quickly before the chicken is fully cooked. Maintaining the oil at the correct temperature (usually between 325°F to 375°F or 165°C to 190°C) is essential for achieving crispy, evenly cooked chicken.

5. **Overcrowding the Fryer:** Frying too many pieces of chicken at once can cause them to stick together and prevent the coating from crisping up properly. Fry the chicken in batches, leaving enough space between each piece to ensure even cooking and crispiness.

6. **Turning Too Often:** Constantly flipping or stirring the chicken while frying can cause the coating to loosen and come off. Allow the chicken to fry undisturbed for a few minutes on each side before flipping it over to ensure that the coating adheres properly.

By addressing these potential issues and following proper frying techniques, you can help prevent the coating from coming off when frying chicken, resulting in crispy, delicious fried chicken every time.