Thaw frozen calamari tubes overnight in the refrigerator. The next day, if the fish is still somewhat frozen, place the package in a bowl of cold water and refrigerate it until thawed.
Rinse the calamari well over a colander in the sink to remove the solution it was packed in.
Hold up a calamari tube and use kitchen scissors to cut off the tentacles at their base. Rinse the tentacles in cold water and feel for any hard, cartilage-like material to remove and discard. Place the tentacles on a paper-towel-lined sheet pan so you can prepare them with the rings.
Peel off and discard the flimsy skin hanging on the side of the squid tube.
Rinse the calamari tube inside and out. Stick your finger inside to feel for any cartilage-like material to remove and discard. (It looks like clear plastic.) You also should scrape off any sand.
Use kitchen scissors to cut the tube into 2-inch-wide rings. Pat the calamari dry inside and out with paper towels and set them on a sheet pan lined with more paper towels to dry. You can let them sit for up to an hour at room temperature before frying. Make sure they're dry before flouring them in the next step.
Make the Calamari Fritti
Add a thick layer of flour (about 2 cups) to another sheet pan. Dredge the calamari in the flour, in batches if necessary. Make sure to get some flour inside the rings, to absorb any excess moisture.
Add some oil to your frying pan until it reaches ½-inch deep. (I used 2 ½ cups in my 12-inch frying pan.) Heat it on the stove, on medium-high. (If making several batches, you may want to use two frying pans.)
Fill a small brown lunch bag halfway with clean, dry flour (or add 1 ½ to 2 cups of clean flour to a sheet pan). Add the flour-dredged calamari to the bag, fold it closed, and shake (or add the floured calamari to the pan of flour and toss it around with your hands). This second coating of flour is to ensure the calamari is dry. Discard any used flour.
When the pan is sizzling hot (the oil should reach 350 degrees F with a food thermometer), gently drop the calamari into the oil in a single layer without overcrowding the pan. (You can use a fork, but I prefer to drop them from my hands.) If the calamari is small, it might be fully submerged in the oil, and you won't need to flip it. Otherwise, the oil will cover the calamari halfway, and you can use a slotted spoon to flip them over when the first side is golden. (Check after two minutes to see if they're ready to be flipped.)
Cook the calamari until they're golden and crispy on all sides. Remove the cooked pieces with a slotted spoon and place them on a cooling rack positioned over paper towels to drain. (This prevents sogginess.) Pat the calamari with a paper towel to absorb excess oil. If you don’t have a cooling rack, you can drain the calamari on a platter lined with paper towels.
Continue frying the calamari in batches. You'll need to change out the oil when the pan gets too filled with excess flour or the oil turns brown. Do this by transferring the used oil to a large metal bowl. Use a wad of paper towels to carefully wipe out the burned bits of flour from the pan. Then add fresh oil. See the notes about how to discard used oil.
To serve, add salt and pepper to taste and squeeze on lemon juice. If not serving them right away, you can cover the fried calamari with foil and keep them in the oven on warm, no more than an hour, until you are ready to eat. Store leftovers in the refrigerator for up to three days. They won't be crispy after the first day.
Notes
It just takes a few minutes to fry each piece of calamari, but you'll need about 30 minutes to fry all of it in batches. If making three or more pounds of calamari, it helps to have two frying pans going at the same time.Oil: You need oil with a high smoke point for frying calamari. Don't use olive oil, or it will burn. You can use avocado oil, corn oil or vegetable oil instead of canola. Replace the oil in the pan with clean oil whenever it turns brown or fills with flour.Disposing of Used Oil - Wait until the used oil has fully cooled, then pour it into a container (such as the empty canola bottle). Throw away the container with the oil.Nutrition facts are estimated.