Sweet and sour garlic head into green, mainly bottle exposure in the visible light, so that the vinegar and garlic photosynthesis, produce a biochemical reaction. According to the relevant information, the northern folk widely spread a special practice of "Laha garlic", is to make the garlic head into green verdant color, there is the meaning of avoiding evil spirits and praying for blessings. The biochemical effect of garlic, the public do not need to be alarmed, you can rest assured that consumption.