Prepare a sheet pan by spraying it with cooking spray, OR line the pan with a silicone mat or parchment paper.
Place the sugar, corn syrup, water, pecans, and salt in a heavy bottomed saucepan over medium heat. Attach a candy thermometer to the pan.
Cook, stirring every few minutes, until the mixture reaches 230°F. Do not turn the heat up—keep it on medium.
After the mixture reaches 230°F, you’ll need to stir the mixture constantly to keep it from burning. It will heat up more quickly at this stage, so keep an eye on the thermometer.
When the temperature reaches 290°F, take the pan off the heat and quickly stir in the baking soda.
Transfer the mixture to the prepared sheet pan and spread out with a spatula.
Allow to cool to room temperature (at least 30 minutes). Then break into pieces with your hands.
Store in an airtight container.
Notes
Make sure that you spray the pan with cooking spray, or opt for a silicone mat or parchment paper instead. Otherwise the brittle won't come off the pan! A candy thermometer works best for this recipe. You can easily double this recipe. Click the "2x" button near the "ingredients" label to get the measurements.