Which two items must be stored in the walk-in refrigerator nightly?

The correct response identifies that whip cream and coffee extract must be stored in the walk-in refrigerator nightly to maintain their quality and safety. Both of these items are perishable and can be affected by heat and time, resulting in spoilage or bacterial growth if not stored properly.

Whip cream, being a dairy-based product, is particularly sensitive to temperature, and storing it in a cold environment helps preserve its texture and flavor. Coffee extract, while it might be somewhat stable at room temperature, can also benefit from refrigeration to avoid any adverse changes that could compromise its quality over time.

Considering the other options, while chocolate syrup, vanilla extract, milk, sugar, bacon, and whipped topping have their own storage needs, they do not pair in the same critical way as whip cream and coffee extract in terms of nightly refrigeration requirements. For instance, milk is indeed crucial to store cold, but the presence of sugar and bacon in those combinations does not align with the stipulation of maintaining them in a daily refrigeration regimen specific to the context of whip cream and coffee extract.