What's the adjective for crumbing? Here's the word you're looking for.
Included below are past participle and present participle forms for the
verbs crumb and crumble which may be used as adjectives within certain contexts.
“With Europe in the doldrums, these dwellings are likely to remain empty, and getting crumblier and uglier by the day, for the foreseeable future.”
“Our intention is to top-dress the track at least three times a year with this sand and get it worked through the soil structure to create a more balanced, crumblier soil.”
“Tempeh is firmer and crumblier and has a stronger, sour flavor.”