There are a number of foods that always pose the greatest challenge when paired with wine. Here are a few:
Vinegar is wine that has been acted on by a bacteria called acetobacter, which turns the alcohol in the wine into acetic acid and water. Another term for the process is called "souring". Because of this, most wines tend to taste spoiled in the presence of vinegar. Look for clean, bright, high acid wines to pair the best, whites being most favorable.
Especially high acid levels in food make it tough to maintain balance. For this reason, look for high acid wines, like those made with Barbera or Vernaccia grapes to provide the greatest balance. Less acidic wines will be overpowered by highly acidic foods.
The complexity and often-weedy flavors in both these vegetables make for tough wine pairing. Look for high acid, grassy wines, like Old World Sauvignon Blanc from the Loire to blend most favorably.
The sulfurous quality of the egg has a similar as vinegar, imparting an unpleasant flavor to softer wines. Look for clean, bright high acid wines to pair best, almost always white.
The cacophony of flavors that abound in cranberry sauce and pickle relish make them near impossible to pair with wine. As with vinegar and eggs, look for clean, bright and high acid wines.
The variability of chocolate in sweetness and texture can be difficult to pair well with wine. For sweeter chocolate, look for sweeter wines to make an effective pair, making sure to maintain balance in the weight and body of each. For semi-sweet or even bittersweet chocolate, look for drier wines to make an effective pair, again making sure to maintain balance in the weight and body of each.