How does isinglass function in the clarification process?

Isinglass functions in the clarification process primarily by forming clumps with yeast cells. This vegetarian-friendly fining agent, derived from the swim bladders of fish, is added to beer after fermentation. Once added, isinglass proteins interact with negatively charged particles, including yeast cells, causing them to clump together. This agglomeration of yeast cells forms larger particles that can then be more easily removed from the beer, leading to a clearer final product. The use of isinglass is especially effective in clarifying beer without imparting any flavors, making it a popular choice for many breweries.

The other methods mentioned, while they might sound plausible, do not accurately describe how isinglass clarifies beer. Changing the pH of the beer is more related to other fining agents or adjustments in brewing, while sterilization is a different process altogether that aims to eliminate all microbial life rather than simply clarifying the beer. Additionally, creating a vacuum to pull particulates is not a function of isinglass but rather a mechanical means used in some brewing processes.