People who frequently brew beer may have encountered this situation. The poor clarification of the fermentation broth easily leads to cloudy beer. So, what factors affect the clarification of the fermentation broth?
The clarification of the fermentation broth is a natural process of coagulation and sedimentation of suspended particles. It is a simple yet time-consuming process. The clarification of the fermentation broth and the sedimentation of turbid suspended particles are greatly influenced by the size of the particles and the viscosity of the liquid. Therefore, in order to expedite the clarification of the fermentation broth, we must try to reduce the viscosity of the liquid and increase the likelihood of particle agglomeration. Additionally, factors that contribute to the clarification of the fermentation broth include the sedimentation of turbid particles in the broth, the diameter of the fermenter tank, the height of sedimentation, and the movement of the fermentation broth. Both irregular movement of the broth and relatively large settling distances affect particle settlement. As a result, both time and the height of the fermenter play crucial roles in the clarification of stored wine.
If the fermentation broth remains cloudy after a certain period of time, the main reasons for this phenomenon are as follows:
Poor quality of raw materials (low malt solubility), inadequate saccharification effect, and the presence of numerous sticky substances in the wort, resulting in high viscosity of the fermentation broth and hindering the sedimentation of particulate matter.
Insufficient storage time, which prevents adequate settling of coagulated particles and yeast.
Inadequate temperature during storage, leading to continuous precipitation of yeast cells and fine particles from cold coagulation, without aggregating into larger particles for settling.
Elevated temperature of the post-storage wine, high yeast cell count, prolonged post-fermentation, continuous movement of the wine body, making it difficult for turbid particles to settle.
The high pH level of the fermentation broth affects the coagulation and sedimentation of particulate matter like cold turbidity. Higher pH levels also increase the viscosity of the fermentation broth, affecting clarification.
The coagulation performance of yeast is weak, inadequate fermentation degree, insufficient protein decomposition during saccharification, and low efficiency in removing cold and hot coagulation, all of which affect the clarification of the fermentation broth.
Contamination of the wort by miscellaneous bacteria and acidification of the fermentation broth result in repulsive charges on certain coagulum particles, preventing their coagulation and settlement.
By understanding the factors that affect the clarification of the fermentation liquid and implementing appropriate measures, I believe that when you brew your own beer, you will also improve the clarity of the craft beer you produce.