In November 2015, Guinness announced that it planned to go vegan friendly and stop using fish bladder gelatin called isinglass to filter its beer. Now, the brewery is finally making good on that plan.

For more than 100 years, Guinness brewery used isinglass to clarify the beer and pull the yeast to the bottom of the brewing tank. It’s still commonly used in cask ales, otherwise known as “real ales” that are served at cellar temperature without extra CO2. Guinness used isinglass at the Dublin St. James Gate brewery to ensure that the resulting beer was consistent and clear.

When the brewery tried to change things up, it didn’t quite work.

“Everything we tried lost that ruby red color you see in the bottom of the glass which shows it’s clear,” the head of quality for Diageo, the company that owns Guinness, told the Times. “We wouldn’t compromise on quality, so we had to wait for the technology.”