In a medium-sized saucepan, combine 8 oz Samuel Adams Boston Ale with 1/2 cup of water, 1/2 tsp minced garlic, 1/2 tsp minced shallots, and 2 tbsp finely sliced celery. Add 1 1/2 lbs mussels, bring to a simmer over medium-high heat, cover the pan and cook for 5 to 10 minutes or until the mussels open. Adjust the heat up or down to maintain the simmer. Using a slotted spoon, lift the mussels from the broth and set aside in a serving bowl. Add 2 tbsp unsalted butter to the broth in the pan and whisk in the butter, a tablespoon at a time, until incorporated. Season to taste with salt and pepper, as needed. Pour the hot broth over the mussels and serve right away.