Often the pH of a fermentation doesn't need to be interfered with, especially if it's grain or molasses-based. Sometimes things do go sideways and an adjustment is needed. Other recipes like sugar washes and generational based spirits tend to be a little bit more of a problem. Either way, it turns out seashells can be a HUGE help in buffering the pH of our fermentations. Happy yeast, happy distiller! Pretty much any shell is going to work. Even eggshells!