Identifying and Troubleshooting Off-flavors

Many new brewers perceive off-flavors in their beer that are simply due to their brews being "green", i.e. not aged for a sufficiently long period of time for the yeast to process fermentation by-products and ultimately flocculate. While some beers, particularly light wheat beers like Belgian Witbier, should be drank quite young, even these styles are usually kept in the primary for about two weeks and another two weeks or more in the bottle before reaching their peak. Most beer styles are about six weeks to two months old before coming into their prime, while others take several months to develop desirable flavor characteristics. So, if you perceive an off-flavor in your beer, the first thing you should ask yourself is whether or not the beer is simply too young. I have brewed some beers that were initially unpalatable, but turned out to be quite drinkable after three months in the bottle.

However, there are off-flavors that indicate a faulty process or infections, and it is important to track down their cause to prevent ending up with multiple less-than-ideal beers in a row. First, reference the beer flavor wheel, which you can find here and assess the flavors and aromas you perceive, taking special note of those that seem to be unbalanced or out of place for the style you were trying to brew. Then, take a look at the excellent BJCP troubleshooting sheet that you can download here for more detail and potential steps to remedy the issue. But don't panic: Infections that are initially plain disgusting often come into their own after extended aging and produce unique and refreshing beverages. When aging infected beer, care should be taken to monitor overcarbonation in the bottle and, if necessary, venting and recapping the bottles repeatedly to avoid dangerous and messy "bottle bombs".

A final point that many new brewers notice is the so-called "homebrew flavor" that is especially prevalent in extract beers crafted by newcomers to the craft. There are a couple of contributors to this flavor: Old extract, concentrated boils, and overemphasis of crystal malts. These can be easily addressed by

1.) buying ingredients from a store with high turnover, ensuring freshness of the extract
2.) boiling a larger volume of wort or, if that is not feasible, adding half of your extract within the last 10 minutes of the boil, and
3.) reducing the amount of steeped crystal malts in your recipes.