Marinate the shrimp overnight for lunch serving or marinate in the morning for dinner use. The shrimp you use have to be somewhat fresh to begin with. If you have stale shrimps, then sorry, pH9 will not save your shrimp. ;) Baking soda is also the secret ingredient Chinese chefs use to make meat tender . You can learn it in my Cashew Chicken recipe . Last but not least, I add a wee bit of baking soda in the batter to make fried foods extra crispy and airy. You can learn more in my sweet and sour chicken recipe .