In a large wok, heat the oil over medium-high to 370 degrees F.
Meanwhile, season 2 cups of the flour with salt and freshly ground black pepper. Dredge the shrimp in the seasoned flour.
In a large mixing bowl, whisk the remaining 4 cups of flour with the egg yolks and soda water. Hold the shrimp by their tails dip them into the batter.
Working in batches, fry the shrimp in the hot oil, turning them once, until they are golden brown, about 3 minutes per batch. Remove the shrimp from the oil and drain them on paper towels. While they are still hot, sprinkle the shrimp generously with salt and freshly ground black pepper. Transfer the shrimp to a serving tray.
When the shrimp are cooked, carefully pour off all but 1/2 cup of the oil. Add the garlic, ginger, green onions and jalapeno and fry until crispy. Spoon the seasoning over the shrimp and serve immediately accompanied by lemon wedges.