Final answer:
The maximum number of times you can re-steam milk depends on the pasteurization method. With UHT pasteurization, the milk can be re-steam pasteurized only once before it undergoes changes in taste and smell.
Step-by-step explanation:
For milk, the maximum number of times you can re-steam it depends on the type of pasteurization method used. One common method is UHT (ultra-high-temperature) pasteurization, which heats the milk at 138 °C for 2 or more seconds. After this process, the milk can be stored in airtight containers for up to 90 days without refrigeration. However, the high temperature used in UHT pasteurization can cause slight changes in taste and smell due to the alteration of proteins in the milk.