Here is a list of some of my favorite sour and bitter foods. If you think your diet is lacking these flavors, try adding a few of them into your weekly meals.
dandelion root tea
Vinegar is both sour and bitter, and very versatile in the kitchen. I probably have seven different types of vinegar in my kitchen at any given time. It can be used to create depth to a dish, or most commonly, to make salad dressings, dips, and marinades.
Today, I used the most common vinegar found in most any home, distilled white, to make pickled carrots. I love adding pickled veggies to salads, or alongside sandwiches, and they are great for a snack. Best of all, you can get very creative with pickling because just about any vegetable can be pickled with most any herb or spice. Pickled carrots, red onions, jalapenos, and beets are some of my favorites. I kept these pickled carrots pretty basic by just adding red pepper flakes and whole peppercorns to the brine.
Also to note:
Pickles are beneficial for aiding digestion after meals. Properly fermented pickles like sauerkraut and kimchi are a good source of the probiotic Lactobacillus acidophilus. However, eat within reason, over-consuming pickled foods can have harmful effects as well.
Source: Pitchford, Paul. Healing with Whole Foods. Berkeley, California: North Atlantic Books, 2003