Remove shells from shrimp and devein. Toss shrimp in 1 tsp and ½ tsp baking soda. Chill for at least 30 minutes.
Prepare poaching liquid. Add water. ¼ c. salt and ¼ c. sugar to water. Bring to a boil, stirring to dissolve salt and sugar. Once boiling, squeeze lemon juice into pan and then add lemons. Keep liquid temperature around 170 degrees.
Prepare ice bath in a large bowl while waiting for poaching liquid to boil.
Poach shrimp for 2 minutes or until just cooked.
Transfer to Ziploc bag and place in ice bath until cooled.
16-25 jumbo shrimp
6 cups water
¼ c. + 1 tsp salt
½ tsp baking soda
¼ c. granulated sugar
2 lemons, halved
4 cups ice