Butter, Sugar, Buttermilk (or milk+lemon juice), Baking Soda, and Vanilla
What if you don't have buttermilk?
Easy peasy. For my double batch of syrup, I needed 1 cup of buttermilk. So I took one cup of milk and added 1 Tablespoon of lemon juice. I mix this part up very first so it has a couple minutes to buttermilk-ify. (Yeah--it's a word...). I love this trick--you can use it anywhere you need buttermilk! You can also use vinegar, but I like the way lemon juice turns out hands down!
Just a Tip:
Use a bigger pan than you think! Looking at the recipe, you will think a small saucepan will do the trick. But there is serious bubble-age here-see? My double batch barely fit in my four quart pot!
1/2 cup Butter
1/2 cup Buttermilk (make your own with 1/2 c. Milk and 1/2 Tablespoon Lemon Juice!)
1 cup Sugar
1/2 tsp. Baking Soda
1 tsp. Vanilla
Melt butter in large saucepan (volume of mixture will increase as it boils). Add buttermilk, sugar, and soda. Stir well. Bring to a boil; boil for one minute, stirring constantly. Remove from heat and stir in vanilla. Makes about 2 cups.