Brewing your own beer at home can be a fun hobby for anybody that loves to enjoy great beer, and would like to get involved in the process of making it. However sometimes you can make a home brew that tastes like cider. If this has happened to you, then you know how bad it can taste when green apples are mixed with beer. I like cider, and I like beer, but I don't like the beer/cider mix. There are a few mistakes that home brewers can make that will give their beer that green apple taste. Let's take a look at some of these mistakes that we can make that gives our home brews this off flavor.
High Fermentation Temperature
One common mistake that can make your home brew taste like apple cider is fermenting your beer at too high of a temperature. This is an extremely easy error to make because, for a lot of us, it is difficult finding a nice cool place to store our fermenting buckets. Yeast does not like temperatures that are too high, and if the conditions are too warm, then our little alcohol producing buddies will create what is known as acetaldehyde. This is the chemical compound that gives us our cider smell and flavor. Yeast are picky little critters, and if you want good beer, then you have to abide by their rules.
Under Pitching the Yeast
Another common mistake is under-pitching the yeast. This is where you don't put in enough yeast to handle the fermentation process, and they get stressed out. Using too little yeast can create a strange fusel taste. Unfortunately, many kits that are sold to home brewers don't include enough yeast, or they give low quality yeast. Your local home brew store should be able to set you up with quality yeast if you believe that this is your problem.
Too Much Sugar
Home brewed beer can also get a cider taste from using too much sugar during the fermenting process. I've heard of people throwing in a ton of sugar to get a higher alcohol content, but this isn't really a good idea for ale or lager yeast. The high alcohol content could end up killing off the yeast before it's finished fermenting.
The final condition that I know of that will give your beer a green apple flavor is contamination. If you don't properly sanitize all of your equipment, then it is possible that your beer will become contaminated. Beer can get infections, and when this happens many off flavors can be produced. If your beer is infected, then you pretty much have to toss it. You definitely don't want to try to drink beer with a ton of bacteria in it. Unfortunately, you'll have to write this one off as a loss.
Brewing beer is a touchy process, and you have to make sure that all conditions are favorable for the yeast to do their job. Keep them happy, and you'll have the satisfaction of drinking great tasting beer that you made yourself. Disrespect them, and you could be sitting with a batch of cidery tasting beer that is difficult to drink.
Sometimes if you age your beer in a cool environment, it will lose some of these harsh smells and flavors. If you have the containers and enough room to store the beer, this is a very viable option.
One recommendation that I would make is that you read up in home brewing forums on the steps for brewing your own beer. I've found that the instructions that come with the kits are usually somewhat vague. The veterans should definitely be able to point you in the right direction as to how to brew. Homebrewtalk.com is a good forum that you can learn a lot about making beer.
One Final Note
Remember, unless your beer is infected, you're not allowed to throw your brew out. Drink it as a reminder so that you will never make these awful mistakes again. It's the international-home-brew-law.