Place the shrimp in a medium-sized bowl with the baking soda. Toss to coat the shrimp. Transfer the shrimp to the refrigerator and let sit for 30 minutes. This will give the shrimp a pleasant “springy” texture.
Pour the water and sake into a saucepan. Add the remaining ingredients and place the saucepan over high heat. Bring the mixture to a boil, then reduce to a simmer. Simmer for 20 minutes.
Add the shrimp to the simmering poaching liquid and poach over low heat until the shrimp turns coral. About 2-3 minutes.
Transfer the shrimp to a plastic bag and dunk it into an ice bath to stop the cooking process.
Place the shrimp in a bowl and place them in the fridge to cool completely.