Fill a medium saucepan with 3 inches of water. The water should be deep enough to cover the eggs by at least one inch.
Add ½ teaspoon baking soda.
Bring the water to a rolling boil over medium high heat.
Turn the heat down until the water is gently boiling.
Carefully add 6 eggs by gently lowering each egg into the water using a slotted spoon.
Set a timer for exactly 7 minutes.
While the eggs are boiling, prepare an ice bath by filling a medium bowl with ice water.
When the timer goes off, carefully remove the eggs with a slotted spoon and transfer them into the ice bath.
Allow the eggs to cool in the ice bath until they are cool enough to handle, at least 10 minutes.
Tap the egg shell firmly on a hard surface to crack the shell and continue tapping the shell on all sides until the egg is cracked on all sides.
Gently peel the shell.
Serve immediately or store in an airtight container in the refrigerator for up to 3 days.
Notes
It is important to note that the time to cook a perfect jammy egg can vary with multiple factors such as the heat the egg is boiled at and altitude. Start with the steps outlined above and adjust the cook time accordingly based on the results.