The Portabello mushroom is one of the tastiest mushrooms available. It is a wonderful mushroom to grill or roast. The caps can grow to as small as 25mm – 75 mm, to the average size of 100mm – 175mm. Our mushroom kit grows several crops of this delicious mushroom. The first crops are the largest, with the third and subsequent crops being smaller. Great on the BBQ or as part of a meatless burger.