As a beer enthusiast and brewer, I can confidently say that storing beer horizontally is generally fine and won't ruin your favorite brew. While many people advise storing beer upright for long periods of time to prevent any potential leaking or yeast buildup on the vessel's wall, those occurrences are actually quite rare.
Firstly, let's address the concern of leaking. While it is true that some beers, particularly those with higher carbonation levels, can experience some leakage if stored horizontally, this is not something that happens frequently. In my personal experience, I have stored various beers horizontally for extended periods without encountering any issues with leaking. However, it's worth noting that if you do come across a beer that has a tendency to leak, it's best to store it upright to avoid any potential mess.
Now, let's talk about yeast buildup. Storing beer horizontally does not necessarily lead to an increased buildup of yeast on the vessel's wall. The amount of yeast present in most bottled beers is usually minimal, and even if there is some settling of yeast, it is not likely to cause any significant problems. In fact, some beer styles, such as bottle-conditioned ales, actually benefit from a small amount of yeast remaining in the bottle, as it can contribute to the flavor development and carbonation.
In my own homebrewing experience, I have stored bottles both vertically and horizontally without noticing any substantial difference in the quality or taste of the beer. However, it is important to handle the bottles with care when moving them from a horizontal to an upright position, as excessive agitation can disturb the settled yeast and potentially affect the beer's flavor.
It's worth mentioning that storing beer in a cool, dark place is generally more important than the orientation of the bottles. Light and heat are the biggest enemies of beer, as they can lead to skunking and off-flavors. So, regardless of whether you choose to store your beer horizontally or upright, make sure it is kept away from direct light and at a consistent, cool temperature.
While some people may advise storing beer upright to prevent potential leaking or yeast buildup, storing beer horizontally is generally fine and won't ruin your favorite brew. As long as you handle your beer with care and store it in a cool, dark place, you can enjoy your beer without worrying too much about the orientation of the bottles. Cheers!