When comparing whole milk, 2% milk, and skim milk, whole milk is generally expected to have more acid content. The acidity in milk primarily comes from lactic acid, which is produced during fermentation.
Whole milk contains the highest level of fats compared to the other types. The presence of fat can influence the milks’ buffering capacity, meaning that it can handle changes in acidity levels more resiliently. Since skim milk has had all the fat removed, it can be more susceptible to changes in acidity due to its lower buffering capacity. Additionally, the reduction in fat in 2% milk may also contribute to a different acidity profile compared to whole milk, making whole milk slightly more acidic.
Moreover, the processes involved in milk production and storage might also introduce varying levels of acidity across these types. Therefore, the expectation of higher acidity in whole milk can be attributed to its fat content and overall composition compared to its lower-fat counterparts.