Toss together cheese and flour in a large bowl until evenly coated; set aside.
In a large saucepan, bring wine and garlic to a gentle simmer over medium, stirring occasionally. Reduce heat to medium-low; add ½ cup cheese mixture, stirring constantly, until melted, about 1 minute. Add remaining cheese mixture about ½ cup at a time, stirring constantly until fully melted after each addition, until smooth (about 8 minutes total).
Reduce heat to low; stir in brandy, lemon juice, and nutmeg until combined. Keep warm over low, or transfer to a small skillet or heated fondue pot. Garnish with pepper, and serve immediately with sausage, bread, apples, and grapes.
