Which of the following statements about starch is true?

Starch is indeed classified as a complex carbohydrate, which is a key aspect of its structure and function. Complex carbohydrates consist of long chains of sugar molecules, making them larger and more complex than simple carbohydrates, which are composed of shorter chains or single sugar units.

Starch is primarily composed of amylose and amylopectin, which are polysaccharides important in the energy storage of plants. When considering the brewing process, the proper breakdown of starch into fermentable sugars is crucial for achieving the desired alcohol content and flavor profile in beer.

The other statements do not accurately describe starch: it is insoluble in cold water, it requires enzymatic action for hydrolysis, and it does not inherently increase pH during mashing. Instead, enzymes like alpha-amylase and beta-amylase are needed to convert starch into sugars during the mashing process, which contributes to pH adjustments depending on various factors such as grain type and water chemistry.