Cap marked "IES 25"
Based on a fortified Guiness Extra Stout recipe
Frankenstein of: - https://beerandbrewing.com/make-your-best-dry-irish-stout/ - https://www.homebrewersassociation.org/homebrew-recipe/full-stop-stout/ - https://brulosophy.com/short-shoddy/short-shoddy-irish-extra-stout/