A lot of unexpected things can crop up on brew day. After the fact, a brewer may wonder what the consequences will be. In some ways, brewing can be very forgiving. On the other hand, there are lines that can’t be crossed without yielding substandard beer. Brewers just learning the ropes may not know if their small mistake will have little consequence, or if it will will ruin their batch. In addition, a brewer who is just learning may not know which sights and smells are normal and which are indicators of a problem. Here are some common occurrences that lead brewers to wonder if they need to worry.
I brewed with old malt/malt extract/hops/yeast. Should I be worried?
Yes. In order to brew quality beer, you need to use fresh ingredients. If your malt is old (over 8 months), it may taste stale. If it is very old (years), it may not have the diastatic power required to convert the starches and sugars. Likewise, malt extract will go stale and darken. This is especially true for liquid malt extract, which should be used within a few months of manufacture. Old hops will have lost some of their alpha acids and may turn cheesy if they are stored improperly. Expired yeast packages may have very low viability. (If the yeast is only slightly out of date, you can usually make a yeast starter and revive it. For a tube or smack pack of liquid yeast, take a small volume of wort initially — around 250 mL — to revive the yeast. Then pitch that to a larger volume of starter wort as soon as any fermentation activity is seen.)