Cut the ampalaya in half lengthwise and remove the seeds and pith with a spoon. Slice the ampalaya thinly.
Blanch the slices in boiling water with a teaspoon of baking soda for about a minute to reduce the bitterness. Quickly remove and plunge into cold water to stop the cooking process. Drain well and set aside.
Slice the carrot, red bell pepper, red onion, and ginger into thin strips. In a large mixing bowl, combine these with the drained ampalaya. Toss gently to combine.
Pack the mixed vegetables into clean jars, pressing down slightly to compact them and eliminate air pockets.
In a saucepan, combine vinegar, sugar, garlic, ¾ cup water, salt, and pepper. Bring to a boil and stir until the sugar and salt are dissolved.
While the pickling solution is still hot, carefully pour it over the vegetables in the jars, completely submerging them
Seal the jars tightly and let them marinate in the refrigerator for at least 24 hours to allow the flavors to meld. Ampalaya Achara will develop a better taste as it sits and can be stored for several weeks in the fridge.