What effect can concentrations of chloride above 300 ppm lead to?

Concentrations of chloride above 300 ppm can indeed lead to chlorophenol production, which is a significant factor in brewing. Chlorophenols are undesirable compounds that can impart off-flavors to beer, often described as medicinal or plastic-like, and they can result from the reaction of chlorine or chlorinated compounds with phenolic substances present in malt. This reaction is particularly a concern in brewing processes involving chlorinated water, where elevated chloride levels can exacerbate the risk of chlorophenol formation during fermentation.

This effect emphasizes the importance of managing water chemistry in brewing. High levels of chloride can alter the perception of flavors but, if not controlled, can lead to negative outcomes such as unwanted off-flavors. In contrast, balancing other ions like sulfate and maintaining low levels of chlorine in water can help brewers produce cleaner-tasting beers.

Other options relate to flavor characteristics or mouthfeel but do not specifically connect to the chemical reactions that occur with elevated chloride levels, making them less relevant in this context.