Combine cinnamon, juniper, allspice and nutmeg in a cheesecloth bag and drop in a saucepan with a quarter of the wine. Add the sugar and orange peel. Simmer to blend flavors, about 6 minutes. Once heated, add the remaining wine and return to a simmer. Remove spice bag and orange peel and serve.
If transporting in a thermos, heat thermos up with hot water to get it warm for 1 minute. Pour water out and fill with mulled wine.
Recipe courtesy of Michael Chiarello