<p>Su Gong explained, &ldquo;only 2-3 year old rice vinegar can be used as a medicine.&rdquo; Ku Jiu has the strongest bitter taste and the best quality will cause heart vexation. The line on Huang Qi Shao Yao Gui Zhi Ku Jiu Tang, explains, &ldquo;Take 1 Sheng of the formula warm and there will be heart vexation. In some cases, there is continued heart vexation, since Ku Jiu leads to obstruction.&rdquo;</p>
