Grease a large baking sheet. Set aside. Measure all ingredients and have them ready to go.

In a medium to large sauce pan, place sugar, corn syrup, water and salt. Stir to combine. (I like to use a wooden spoon when making candy)

Heat mixture over medium heat to dissolve the sugar. Stirring occasionally so it will not burn.

Add butter and stir frequently to blend the butter with the sugar mixture. Bring mixture to a boil. Do not turn heat up-keep on medium heat.

As the mixture boils, use a candy thermometer to watch the temperature.

When mixture reaches the thread stage-230° F, stir frequently. Enough to avoid burning.

When mixture reaches the soft crack stage-250° F, add peanuts and stir continually until your candy reaches 295-300° F.

Immediately remove from the heat and stir in vanilla and baking soda. (I remove mine a couple degrees before 300-my pan stays so hot it will keep cooking and can burn if you don't move quickly)

Quickly pour mixture on prepared baking sheet and use your wooden spoon to spread the brittle out so the peanuts are in a single layer. Do not scrape the pan.

Allow time to cool completely. Then, break up, enjoy and store leftovers in an airtight container.