Steam is the enemy of crispness. And although it's a common practice, draining bacon on paper towels after cooking it, even if only for a couple minutes, creates steam from the bottom up, causing limpness.
If you need to keep bacon crispy longer than a few minutes, avoid paper towels for degreasing it and never cover it with a bowl or dish to keep it warm --use the oven instead.
Drain bacon slices on a cooling rack set over a sheet pan instead of a plate lined with paper towels. Line the sheet pan with paper towels to absorb any dripping bacon fat and set the wire rack on the pan. Transfer the bacon slices to the rack using tongs or a slotted spatula immediately after cooking, and let them drain for about one minute before serving.
Freezing and refrigerator storage don't affect cooked bacon's crispness, which you can restore during reheating. If you want to keep freshly cooked bacon crisp and warm, the oven is your best choice.
Set the oven to 200 F or on its Warm setting. Line a sheet pan with a single layer of paper towels and set a cooling rack on it. Lay the bacon strips on the rack and set the sheet pan on the middle oven rack. Prop the oven door open 1 to 2 inches with a folded towel. You can keep the bacon crisp and warm up for around two hours before it starts drying out.
Reheat bacon in the microwave to restore crispness. Microwaves draw moisture out of food, which maintains crispness.
Let the bacon reach room temperature after taking it from the refrigerator or freezer. Next, place the bacon on a plate lined with a paper towel. Microwave the bacon in 20-second increments until it's heated through. High-powered microwaves take about 30 seconds and smaller microwaves take between 45 seconds and 1 minute.
Baking bacon to extra crispness helps compensate for any softening that may occur later. Line a sheet pan with parchment paper and set a cooling rack on it. Space the slices about 1/4 inch apart on the rack. Bake the bacon at 400 F for 20 minutes, or until it reaches the desired crispness.
To make crispy bacon bits, first cook bacon strips -- four slices make about 1/2 cup of bits -- until crispy and chop them after they cool. Store bacon bits as you would strips, in the freezer or in an airtight container in the refrigerator.