What characteristic of calcium carbonate affects its dissolution in brewing?

Calcium carbonate is known for its role as a buffering agent in brewing, especially in regards to pH manipulation during the mash process. Its dissolution behavior is significantly influenced by the acidity of the solution. In a neutral or alkaline environment, such as plain water, calcium carbonate does not readily dissolve. However, when in an acidic environment, such as the mash, it becomes more soluble.

This phenomenon occurs because the carbonic acid formed in an acidic environment can react with calcium carbonate, leading to its dissolution into calcium ions and bicarbonate ions. This is critical in brewing as it can contribute to the overall mineral profile of the brewing water and help with mash pH levels, which can impact enzyme activity and ultimately the quality of the beer.

The other options misrepresent the nature of calcium carbonate. For example, it does not dissolve readily in all temperatures; its solubility is highly dependent on the pH of the solution rather than temperature alone. Similarly, saying it dissolves in water but not in mash negates its role in the acidic environment created during mashing. Lastly, claiming that it doesn't dissolve in water but does in mash oversimplifies the conditions under which calcium carbonate will dissolve. Thus, the correct understanding of its behavior is that