Feebtlas, cask conditioning is not a verb, but a gerund.  Gerunds, by definition, are nouns, and by well-established precedent, acceptable for article titles. If we call it Cask-conditioned ale, it not only excludes lager, but cider, perry and mead, which for centuries have been cask conditioned.   If the article is describing a brewing process, than its title should use the gerund form, for example, brewing, cooking, baking, frying, steaming, boiling and nearly all the articles under Cooking#Cooking_techniques.