Why is adding milk fat to chocolate only a context-dependent way to reduce bloom?

Answer: Milk-fat fraction matters

Milk-fat fraction matters ✓ — Correct. Milk fat can interact with cocoa-butter structure and help inhibit bloom, but the effect depends on the milk-fat fraction. UW and JAOCS summaries both report high-melting fractions inhibiting bloom while low-melting fractions can induce or promote it. The payoff is that melting behavior matters as much as the ingredient name.

Milk fat blocks all water — This confuses fat bloom control with moisture exclusion. Sugar bloom is about water dissolving sugar, but the milkfat findings concern cocoa-butter structure and polymorph change. The useful contrast is that blocking humidity and tuning fat crystals are different storage problems.

Milk fat removes Form VI — This overclaims the mechanism. Bloom can involve Form V slowly transforming to the more stable Form VI, but the cited milkfat work does not say milk fat removes Form VI. It says specific fractions can alter crystallization and either inhibit or promote bloom.