In small saute pan, cook bacon over medium heat, stirring occasionally until browned and crisp, about 8-10 minutes. Using slotted spoon, transfer bacon to small bowl.

Cut 1 stick butter into pieces. Add pieces to drippings and cook, stirring often, until butter foams and browns, about 5-8 minutes.

Strain mixture into medium bowl or bowl of stand mixer. Stir in minced shallot.

Allow bacon fat-butter mixture to cool 30 minutes, or until it reaches room temperature.

Add remaining stick butter to bacon fat mixture. Using hand mixer or stand mixer, beat until light and fluffy. Add chives, vinegar and reserved bacon. Season with salt and pepper, to taste.

Place butter mixture in refrigerator and allow to firm slightly. Butter can be made up to 3 days in advance. Remove from refrigerator 1 hour prior to serving to allow butter to soften.