Vinegar often plays an essential role in the food we eat. We use it in everything from baking to braising to pickling. But, author Michael Harlan Turkell writes that vinegar is "underappreciated and little understood." For his new book Acid Trip: Travels in the World of Vinegar: With Recipes from Leading Chefs, Insights from Top Producers, and Step-by-Step Instructions on How to Make Your Own, Turkell set out to give vinegar its due. He traveled the world, learning how countries from Japan to France make and use vinegar. He also collected recipes from chefs who are using vinegar in exciting, different and delicious ways. He joins us for our latest Please Explain to discuss vinegar's many uses and how you can make your own at home. Micheal Harlan Turkell will appear in conversation with Francine Segan, Ivan Orkin and Neil Kleinberg at the 92nd Street Y (1395 Lexington Ave. at 92nd St.) on Dec. 7 at 7 p.m. Check out a recipe from Michael Harlan Turkell's Acid Trip below! OEUFS EN MEURETTE, FROM BERTRAND A UBOYNEAU, BISTROT PAUL BERT, PARIS, FRANCE SERVES 4 This dish takes the concept of bourguignon sauce and uses it to poach eggs. What you’re left with is the same rich stock, adding the decadence of a creamy egg yolk, with a side of toast to sop it all up. Bertrand, always in need of acidity, uses a portion of red wine vinegar in place of some of the red wine, which gives a much lighter quality to a dish that usually invites a postprandial nap, and instead has you feeling like conquering the day ahead. ¼ pound (115 g) THICK SMOKED BACON, cut into lardoons 1 tablespoon BUTTER ¼ pound (115 g) WHITE PEARL ONIONS, peeled, tops and bottoms trimmed 1 clove GARLIC, crushed ¼ pound (115 g) BUTTON MUSHROOMS, cleaned, cut into quarters 3 cups (720 ml) RED WINE, such as Burgundy, Beaujolais, Cabernet 1 branch THYME 1 cup (240 ml) RED WINE VINEGAR 4 EGGS, kept in shell, cold BLACK PEPPER PARSLEY LEAVES, optional TOAST and BUTTER   In a large saucepan over medium heat, render the bacon for 5 to 7 minutes, until it’s just browning but not burning. If it’s cooking too fast, lower the temperature. Pour out all but about 1 tablespoon of the fat (reserve the excess to cook with another time) and set the bacon aside (you’ll add it back in later, so try not to snack on it too much). Add the butter, onions, and garlic and cook for about 1 minute, until aromatic. Lower the heat to medium-low, add the mushrooms and cook for another 2 minutes, stirring occasionally. Add the red wine, scrape the bottom of the pan to release the fond, and add the thyme. Bring back to a simmer and cook for 45 minutes, or until reduced by a third. Add the red wine vinegar and continue to cook for another 30 minutes. (If it’s too acidic for your taste, add ¼ cup water at a time until it’s not.) To poach the eggs, either in the pot of sauce itself (if you don’t mind a few stray pieces of egg white) or in a separate pot of water, bring the liquid to a bare boil. Make a small pinprick on the larger end of each egg, place in the liquid, and cook for 30 seconds (a Julia Child tip); this is just to set the whites. Remove the eggs and crack them into individual small bowls. Slide the eggs back into the pot to poach them. If you like a soft yolk, cook for only a few minutes. Using a slotted spoon, remove the eggs and set aside. In individual serving bowls, evenly distribute the onion and mushroom mixture, then pour a bit of the sauce, enough to cover an egg, into the bowl as well. Place the eggs into the bowls and garnish with the bacon, freshly cracked black pepper, and parsley, if using. Bon appetit! Note: Jonathan Capehart guest-hosted this segment of The Leonard Lopate Show.