Romanesco broccoli, also called Roman broccoli, takes its name from the days of Julius Caesar and remains a popular cruciferous vegetable for its sweet flavor and dense texture. It only keeps for a few days in the refrigerator, but you can preserve the florets in your freezer for later use. The yellow-green, cone-shaped Romanesco head contains several tiny, cone-shaped florets similar to broccoli and cauliflower florets, and like its cousins must be blanched first to maintain that satisfying crunch.
Cut the florets away from the stem. You can keep multiple florets in clusters or cut them off individually, depending on your preference.
Soak the florets in a mixture of salt and water, using about 4 tablespoons of salt per gallon of water, for about 30 seconds to remove any insects that might be nestled inside the dense florets.
Bring a large pot of water to a boil. Fill a bowl with equal parts water and ice and keep the bowl ready beside your sink. Place a colander in the sink.
Blanch, or boil for two to three minutes, to stop the enzyme action that leads to maturation and rotting in fruits and vegetables, which can occur even when frozen raw. Without blanching, the florets can become tough and lose much of their flavor.
Strain the Romanesco through the colander and immediately place the florets in the ice bath to stop the cooking process. If you leave the florets in the colander to cool, they will continue to cook as a result of the heat from the blanching process. Leave the Romanesco in the cold water until cool, replacing the water with more cold water, if necessary. This takes but a few minutes.
Return the Romanesco to the colander to drain the water. Pat them dry with a towel or paper towels to remove as much water as possible. Water frozen on the florets causes the cell walls to break down, giving the florets a freezer burnt taste.
Place the florets on a baking sheet, leaving a space between each piece. Set the tray in your freezer for about 30 minutes to freeze them. Remove the tray from the freezer. This freezes the florets individually so they don't freeze together as a solid clump in the bag, allowing you to remove individual florets from the bag as needed.
Fill plastic freezer bags with the frozen Romanesco florets up to the top of the bag. Seal the bags tightly, removing as much air as possible. Label each bag with the name of the vegetable and the date of processing. Store in the freezer for up to about 12 months.