Have you ever looked into a bottle of craft beer/cider and seen a layer of fine looking powder-like sediment in the bottom? Don’t throw it out just yet, it’s probably just natural and perfectly safe to consume brewing yeast. This yeast is no worse for you than the yeast found in bread for example, and it can be consumed or carefully avoided for appearance sake by pouring the beer into a glass just short of the small yeast cake. The presence of yeast at the bottom of the bottle simply means the beer was carbonated naturally as opposed to forced artificial carbonation.
Homebrewers will be familiar with the concept of natural carbonation already as for the beginning brewer it is the most accessible method of carbonating brews. Natural carbonation uses yeast in the uncarbonated beer for carbonation. The brewers add a measured amount of priming sugar to the uncarbonated beer just before bottling. Once bottled the yeast will wake up and consume the newly added sugar, producing the desired carbonation as they do so. In the process, they will multiply and then drop to the bottom of the bottle when they have consumed all of the sugar. Although this process is the standard for homebrewers there are some major breweries that also carbonate their beer in bottles. The most popular beer on the top of my head that utilizes bottle priming is the Sierra Nevada Pale Ale.
The most popular beer on the top of my head that utilizes bottle priming is the Sierra Nevada Pale Ale. The reason you may not have noticed yeast at the bottom of these popular craft beers is that these breweries have often perfected the art of bottle conditioning and have found ways to minimize the yeast in bottles while at the same time providing what they feel is a unique taste only achieved by bottle priming. Alternatively, some breweries and home brewers have begun filtering out the brewing yeast, and then adding a special bottling yeast that produces very minimal sediment in the bottom of bottles.
“Force carbonating will allow you to hit your desired level every time, without exception” –Homebrew.com
Artificial carbonation can be done in a variety of ways at different levels of brewing. For all of the methods of force carbonating the goal is the same; to get the desired level of carbonation into the brews without the sediment normally added from naturally carbonating brews. By artificially carbonating the brew it also ensures that the yeast won’t be stirred up and cause the beer to appear cloudy. Most of the craft beer industry utilizes artificial carbonation for consistency and the ability to carbonate beer faster than via natural yeast carbonation.
“What many Reinheitsgebot purists fail to realize is that they cannot add priming sugar or extraneous CO2 to carbonate their beers. Large commercial brewers solve this problem by harvesting the CO2 from fermentation and reinjecting it into the beer. The small brewer, however, must carbonate beer naturally by kraeusening.” –BYO.com
Next time you are looking for craft brew in the store, check out the bottom of some of the bottles. You might just find a layer of yeast from natural carbonation!