In neighbouring countries like Malaysia and Singapore, the name tom yum is used widely for various spicy soups which are different from true Lao and Thai tom yum. So, people are often confused by the difference.
Tom yum paste is made by crushing all the herb ingredients and stir frying in oil. Seasoning and other preservative ingredients are added. The paste is bottled or packaged and sold around the world. Tom yum made with this paste may have different characteristics from that made with fresh herb ingredients. The soup often includes meats such as chicken, beef, pork, or shrimp.