The acidity makes all the vegetables in borscht tough and will remain hard no matter how long they cook. Therefore, it's recommended to add tomato paste at the very end, frying or simmering it with the beets or sautéed vegetables toward the end. Vinegar, citric acid, or lemon juice should also be added at the end. Otherwise, the cabbage and potatoes will be too tough. This tip comes from my 83-year-old Ukrainian grandmother, a seasoned borscht cook. For an interesting flavor and aroma, you can cook borscht with pickled beets and sauerkraut. Try it; it has a very piquant, subtle aroma. Also, add a pinch of dill. If you're using beef ribs, add 1-2-3 cloves and a pinch of caraway seeds. To give the tomato paste a piquant, red color, fry it; you can also add it with the sautéed vegetables, as long as it's well-dried. A tablespoon of butter added to the frying at the end will add a delicate aroma and flavor to your borscht, and pounded with lard or even old fatback is a treat for true connoisseurs who have especially enjoyed or have tried Ukrainian borscht. What's the trick? Try it; it's hard to describe. Cook with beef, not veal. The older the beef, the darker the meat—it's perfect for borscht; it's richer and has the right flavor, and it should be bone-in, of course. The same goes for cabbage: a winter variety, old cabbage—orna in particular—will also impart a piquant flavor and aroma; young cabbage is useless, for shchi. When cooking the meat, add diced onion and carrots in addition to the fried vegetables. Raw onions and carrots will infuse the broth and meat with flavor. Borscht is a picture that can be painted in many ways; it's an amazing dish.