Bob Brewer answers your questions about the world of beer and brewing.

Bryan (via Facebook): Bob, could you please address beer ‘floaties’ – the particles sometimes hanging out in the bottles of craft beers?

Bob: Good one, Bryan. There are different types of ‘floaties’ caused by different things. I like to think of them as the good, the bad, the very bad, and the ugly.

The good: The beer has been bottle-conditioned. Bottle conditioning is a deliberate process whereby a small amount of active yeast and sometimes a bit of fermentable material such as maltose or some other type of sugar is added to the bottle prior to capping it. Sometimes the bottle will be filled with beer that is still fermenting. Either way, the result is a mild fermentation taking place in the enclosed bottle which creates a natural carbonation and a small increase in the alcohol content.

However, there will also be yeast in the bottle, some of which was left there and some that was generated by the fermentation. This yeast will settle to the bottom of the bottle but will become “floaters” when the beer is agitated or moved – like when you are pouring it or drinking it. It’s not bad and doesn’t affect the flavor. Bottle-conditioned beers can be quite good and the yeast is a part of the experience.

The bad: Several things here. First – and probably most common – is that the beer is just plain old. Some craft beer has been known to get lost on the shelf for ages. While we all know that some beers such as barley wines and strong ales can be laid down for extended periods and actually improve with age, this is not the case with many other beers. Age can destroy beer. The liquid breaks down, the proteins fall out, the hop character goes away and the beer tastes stale, oxidized, and musty.

In this case, the floaters tend to look like snowflakes rather than the yeast sediment from bottle conditioning. “Snowflake” beer should be avoided. Also bad but not necessarily fatal is poor filtration at the brewery, which allows particulates to end up in the bottle. This is mostly a cosmetic thing, but its presence reflects inattention or poor practice by the brewer.

The very bad: The beer is infected and spoiled. Poor sanitation, bacterial contamination. You will know immediately if this is the case, as the beer will smell bad and taste awful. It won’t kill you if you drink it but if it smells bad it’ll taste worse. Some beer from small breweries is packaged unpasteurized. This can be a good thing if the beer is kept refrigerated and consumed fresh. However, an unpasteurized beer can have a limited shelf life and be subject to spoilage. Spoiled beer can have floaters and may also appear cloudy.

The ugly (But not bad): A significant amount of yeast has been intentionally left in the beer as a part of the style. Think German-style hefeweizen. While some American-style hefe beers have been processed so as to keep the yeast in suspension, this is not always the case. The yeast can sit on the bottom of the bottle in a thick mass. There are examples with so much yeast in them that the beer looks muddy and the sediment will actually be so thick that it has to be coaxed out of the bottle in chunks. Big, fat floaters. Thick brown sludge oozing from the bottom of the bottle: not very appetizing. For these beers it is recommended that the bottle be laid on its side and gently rolled back and forth for a few minutes so as to “rouse the yeast” and get it into suspension before pouring. Bottled beers of this type should always be roused and then poured into an appropriate glass. Great beers if served properly.

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