For the Beer Batter:
1 1/2 cups Samuel Adams Boston Lager
1 1/2 cups all-purpose flour
3 tablespoons smoked paprika
1 teaspoon fresh ground black pepper
1 tablespoon ground espresso beans
2 tablespoons ground mustard seeds
For the Onion Rings:
2 large yellow onions
3 cups buttermilk
1 teaspoon ground espresso beans
1 gallon canola oil for frying
IN A LARGE mixing bowl whisk together flour, paprika, pepper, espresso and mustard seeds. Whisk in beer until smooth. Let rest for 10 minutes.
PEEL the onions and slice them into 1/2-inch rings. Steep the espresso beans in 1/4 cup buttermilk, then add this portion to the remaining buttermilk. Soak the onion rings in the buttermilk for at least 20 minutes.
HEAT the oil in a 2 gallon heavy-duty bottom pot to 375°F. Set aside a plate lined with paper towels.
PLACE the onion rings in batches into the beer batter, then take one at a time and gently place them in the oil.
LET each ring cook for 3 to 4 minutes until golden brown. Scoop them out with a slotted spoon and place on paper towels. Repeat until all onions are fried.