What effect do alpha acids have when dissolved in wort during the boil?

The isomerization of alpha acids during the boil is a critical process in brewing that contributes to the bitterness of the final beer. When hops are added to the wort, the heat from the boiling liquid causes the alpha acids present in the hops to undergo a chemical transformation. This process converts the alpha acids into iso-alpha acids, which are soluble in the beer and impart a distinctly bitter flavor.

The bitterness from the iso-alpha acids is a key component of the overall flavor profile of the beer, balancing sweetness from the malt and creating a more complex taste experience. This is why adding hops at different times during the boil can result in varying levels of bitterness: the longer the hops are boiled, the more alpha acids are isomerized and thus the higher the bitterness.

Other options do not accurately represent the effects of alpha acids during the boil. They do not become insoluble or dissipate in the way described, nor do they contribute to sweetness. Understanding this transformation and its impact on the final product is essential for creating balanced and flavorful beers.