Cut broccoli into bite sized pieces. Blanch in boiling water for three minutes or steam for five minutes. Cool in ice water for the same amount of time you heated it. Dry the broccoli as best as you can before freezing. A salad spinner works well. Alternately, you can drain the broccoli with a colander and then spread it on a towel and blot dry. Work quickly; it's best to shift broccoli as quickly as you can from ice water to freezer. You want the broccoli thoroughly dry. Quick freeze broccoli on a parchment-lined tray for about 30 mins. and then package into air-tight freezer bags. Use within a year.