What is acceptable to observe in a bottle of beer before serving?

Observation of a light beige or tan yeast residue on the bottom of the bottle is acceptable and often expected in certain styles of beers, especially those that are bottle-conditioned. This residue consists of yeast and proteins that settle as the beer ages and can be a sign of a traditional brewing method where the beer is naturally carbonated in the bottle.

In many craft beers, particularly those that are unfiltered and have undergone natural fermentation, this yeast sediment is normal. It can indicate a process that adds character to the beer, such as bottle conditioning, and does not generally impact the flavor negatively when poured properly. Often, those who enjoy these styles appreciate the presence of yeast, as it can contribute to the complexity of flavors and aromas in the beer.

In contrast, the other options represent observations that are typically undesirable. A ring of debris around the neck at the liquid level can indicate poor cleanliness or a brewing issue. Haze in a pale lager usually suggests a flaw in the brewing or filtration process, while white flakes swirling in the bottle can imply spoilage or unwanted elements like wild yeast or bacteria.