What happens to beta acids during the boil?

During the boiling process in brewing, beta acids do not undergo isomerization, which distinguishes them from alpha acids. Alpha acids, when boiled, are isomerized into iso-alpha acids, which are responsible for the bitter flavor in beer. In contrast, beta acids remain largely non-soluble and largely unchanged during boiling, meaning they do not significantly contribute to the bitterness of the beer in the same way that isomerized alpha acids do.

While beta acids can have some degree of solubility, their primary function does not involve forming iso-beta acids as alpha acids do; therefore, they do not actively contribute to the flavor profile in the same manner. It's also worth noting that while beta acids are not typically converted or solubilized significantly during the boil, they can contribute to other flavor characteristics and may lead to some unique aroma when used in specific hopping techniques or later in the brewing process.