Sniffing Milk
Just as when one is approaching a perishable item such as milk, when one is " Sniffing Milk" one is treading carefully and investigating in order to avoid potential disaster.
Mondale was cautious about investing in the new business venture, so he spent extra time sniffing milk.
Milk Sniffing
When you sniff milk to see if it is still fresh.
Yo, that guy was milk sniffing!