Clean and dry the mushrooms. Trim or remove the stems (it is easier to bread them with the stems removed)Toss them in the 2 Tbsp of flour about 6 at a time and place the flour coated mushrooms in a colander. Shake the excess flour off by gently moving the colander back and forth or tapping on a tray to catch the flour. The mushrooms only need to be lightly coated with the flour.
Add the cold water and the cold egg to a deep round bowl and whisk to combine.
Sift the flour in 1 Tbsp at a time to cover the surface of the liquid. Gently fold the flour into the egg/water mixture until it is incorporated. Don't whisk or beat the flour in or the gluten will develop and become gummy. Some clumps are normal, so don't be concerned. If you have large clumps, press them against the side of the bowl to break them up. Repeat until all the flour is used.
The consistency should be like a thin pancake batter. If it is too thick, add a small amount of water (1-2 tsp) at a time and fold the cold water into the mixture until the correct consistency is achieved. See post for more details and short video.
Combine the bread crumbs with the seasonings in a bowl that is several inches deep. I used basic seasonings, but you can add whatever spices you want.
Preheat the Air Fryer
I usually do this right before I begin breading my mushrooms because it takes about 10 minutes to bread them all.
No matter what air fryer you are using, preheat on the hottest setting for a full 10 minutes with the tray or basket in the air fryer.
Battering and Breading the Mushrooms
Place one mushroom in the wet batter, cap side down and flip it over with a fork. Make sure the batter is covering the entire mushroom. Lift out of the wet batter with the fork and place in the dry mixture, cap side down. Spoon (or use a clean fork) the dry breading over the entire mushroom. Carefully, flip it over and use a spoon or fork to place the breaded mushroom on a plate or a cooling rack. Repeat for all the mushrooms.
Air Frying the Mushrooms
When the air fryer is preheated, spritz some oil on the tray or basket. Place the mushrooms stem side down onto the tray or basket. Make sure the mushrooms are not touching each other. How many you can do at once depends on your air fryer.
Spritz the tops of the mushrooms with oil, making sure to lightly coat the breadcrumbs.
Air Fry on 325°F/160°C for 10 minutes. While you don't have to flip, I recommend flipping them over after 5 minutes. * see notes for air fryer oven temperature adjustments.
Remove the mushrooms and place them on a cooling rack. This is important so they don't steam and create a soggy bottom.
The time in this recipe is based on one batch. You may need to cook the mushrooms in several batches depending on the size of your air fryer. If you are using an oven style air fryer, I recommend increasing the temperature by 25° for a small oven air fryer (the size of a toaster oven) and 50-75° for a larger air fryer oven. The cook time was the same. Nutritional values are provided as a courtesy and thesaltedpepper.com makes no guarantees of accuracy. We do our best to ensure they are accurate, but many factors influence nutritional values that are beyond our control. Different brands of items have different nutritional values, so it is always best to do your own independent nutritional analysis based on the items you are using in a recipe if you require a high level of accuracy. Thesaltedpepper.com will not be held accountable for any errors in the displayed nutritional information.