Munich Malt III pushes the Munich malting process about as far as it goes while still technically qualifying as a base malt — 25-35 °Lovibond, deep toasty-malty flavour well past what Munich I or II show, and diastatic power that's dropped to only around 10 °Lintner. That's thin enough that most brewing references treat it as needing real enzyme support from another base malt rather than functioning as a self-converting foundation the way Munich I still can.
Its conventional ceiling sits around 40%, lower than Munich I's near-100% and closer to Munich II's 60%, reflecting how little enzyme margin it brings to a mash on its own. Brewers building an intensely malty dark lager or strong bock sometimes blend Munich III with Pilsner or Pale 2-Row specifically to restore that margin while keeping the deep malt character Munich III alone can't safely carry at full strength. It's noticeably less commonly stocked than Munich I or II, since its narrow niche — maximum Munich intensity, blended rather than used alone — appeals to a smaller slice of recipes than the more flexible lighter tiers. Brewers who can't source it directly generally approximate its contribution with Munich Malt II plus a small crystal malt addition rather than searching further and further afield for the one remaining maltster who still carries the darkest tier of Munich malt specifically.