Chop the bacon into small bits about a 1/4-inch in size.
Butter a rimmed baking sheet or line it with a Silpat.
In a large, heavy-bottomed saucepan, combine the sugar, water, butter, and syrup. Bring to a boil over moderate heat, stirring occasionally until the mixture reaches 300°F on a candy thermometer, about 10-15 minutes.
Remove from heat and stir in the baking soda, then the bacon bits. Immediately pour the mixture on the prepared baking sheet. Use a large spoon (If it sticks, oil it lightly.) to quickly spread the brittle into a thin, even layer. Sprinkle with sea salt.
Allow the brittle to cool completely, then break into pieces. Store in an airtight container.