Make The Sushi Vinegar: Combine all of the sushi vinegar ingredients in a small sauce pan and let the pan sit on low heat for 10 minutes, letting the sugar melt completely. Let the vinegar cool to room temperature and remove the kombu seaweed before using. 

Make the rice: Wash the rice, gently swishing the grains with your hands. Rinse and repeat. Drain carefully into a colander and put the rice in a medium sauce pan. Add the water to the pan and let the rice sit for 15-30 minutes. (This helps the rice start absorbing the water and cook more evenly).

Bring the rice to a simmer over medium heat. Lower the heat to medium low and use a fork to gently go around the inside of the pot, unsticking any stuck grains. Cover with a tight fitting lid and cook the rice for 10 minutes. 

Lower the heat to the lowest setting and continue cooking the rice for 8 minutes. Once the rice is done, turn off the heat and let the rice sit for 5 minutes.

Take a spatula and go around the inside of the pan to help get the rice out. Flip the pan over onto a large bowl and scoop the rice out. Pour the sushi vinegar onto the rice and then start a gentle chopping motion with the spatula to mix the vinegar into the rice. Take care not to crush the grains of rice.

Let the rice cool for 5 minutes and then again gently mix the rice with a chopping motion.

Let the rice cool to room temperature before using. 

Prepare the ingredients: Mix the wasabi and set aside. Cut the avocado in half, remove the seed, and then cut the avocado into 8 small wedges, removing the skin. If there is plastic wrapping on the crab sticks, remove it. 

If you want to try any of the optional ingredients, get them ready too. Trim a small persian cucumber and then cut it into thin wedges. Cut off the seeds, which make the sushi rolls soggy. 

Place all of your ingredients on the counter when you are already to make your sushi rolls.

Make The California Rolls: Prepare your bamboo mat by wrapping it a couple of times in plastic wrap. Make sure to squeeze out any air as you wrap it. Then take the tip of your knife and gently poke several holes (between the slats of the bamboo) into the plastic wrap to remove any trapped air.

Place the seaweed, rough side up, onto your counter. Scoop 1 scant cup (between 3/4 to 1 cup) of rice onto the sheet of seaweed. Lightly wet your hands and gently spread the rice across the sheet of seaweed, making sure to go just up to the top but making sure you go slightly over the bottom edge (this is so when you make your roll, the bottom edge will stick easily because of the slight overhang of rice).

Place 2 pieces of avocado in the middle of the roll and split one piece of crabstick and place it on top of the avocado. If you want to add any optional ingredients, do so with a light hand. You do not want to put too much filling and not be able to close the roll.

Pull the edge of the bamboo mat up while also holding onto the edge of the roll. Fold the bamboo mat over the the ingredients, so the rice encloses the ingredients. Push down to secure the roll and then pull the mat while rolling the sushi roll to completely close it. 

Pull the edge of the mat to each end, pushing into the roll with your fingers to straighten the ends.

Repeat with three more pieces of seaweed. You will yield 4 california rolls.

Using a sharp knife and a damp towel. Cut the rolls by first wetting your knife on the towel and cutting through the middle of the roll. Repeat wiping your knife and cutting through the rolls twice more so you yield 8 evenly sized pieces. (If you like your rolls thinner, you can make 5 or 6 cuts across the rolls. Make sure your knife is very sharp, otherwise just stick to 4 cuts, or you will make a squished mess).

Arrange the rolls on a platter and garnish with wasabi and some pickled ginger. Serve with soy sauce.