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 (If the yeast is only slightly out of date, you can usually make a yeast starter and revive it.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.)
I mashed in too low/high. Should I be worried?
It depends. If you mashed in too low, you can simply increase your mash temperature with few negative consequences. You may produce a wort that is more fermentable that you planned on, but the wort won’t be ruined. If you work relatively quickly, and boost the temperature into the right range — by adding boiling water or direct heat — within 5–10 minutes, everything will be fine.
If you mashed in too high, you can simply stir in room temperature tap water to decrease the temperature of your mash. If your initial mash temperature was less than 162 °F (72 °C), and you corrected the problem within a matter of minutes, you should have no problems. Worst case scenario is that your wort will be slightly less fermentable than you planned.
If your original mash temperature was over 162 °F (72 °C), you will have begun to destroy some of the starch-degrading enzymes required. Beta amylase, in particular, is fairly fragile at elevated temperatures. However, if you get the temperature down within a matter of minutes, you will likely be fine. It takes a while for proteins to denature. If you mashed in very high, but cooled the wort down quickly, you may want to extend your mash time — by say, 15–30 minutes — to compensate for any loss of enzymatic power.
If you mashed in very high, and didn’t discover the problem for a while (say, over 20 minutes), you will likely have a problem. You will likely have denatured enough of the amylase enzymes that your wort will not completely convert. If you have any American six-row pale malt, or American two-row pale malt, you can crush that and stir it into your mash. In the right quantities, these high-enzyme malts could supply enough enzymatic power to rescue the mash. (Of course, the resulting wort will be different from what you planned.)
The wort won’t clear when I recirculate. Should I be worried?
No. Sometimes, especially when brewing a lighter-colored beer, no amount of recirculation will make the wort perfectly clear. In this case, the small amount of solids that carry over to the kettle will not cause problems. Specifically, slightly cloudy worts will not lead to cloudy beer. The solids causing the wort to be cloudy – largely proteins — will simply coagulate during the boil.
My wort boiled over. Should I be worried?
When wort boils over, it is usually just an annoyance, not something that is detrimental to the quality of the beer. You may lose volume, however. Also, if you had just added hops, some of those might now be on the ground. In that case, you would need to estimate how many how much hops were lost, and replace them.
After a boil over, see how much wort you have left and make the necessary adjustments (hop additions, etc.) to brew a slightly smaller volume of beer.
I forgot to add the Irish moss. Should I be worried?
Not really. Your beer maybe a bit cloudier than usual, however.
I dropped something in my chilled wort, and fished it out with my hands. Should I be worried?
Occasionally, a brewer will accidentally drop something — a thermometer, pH meter, cell phone, etc. — into chilled wort. Instinctively, he or she will reach into the wort and grab it, contacting the wort in doing so. When this happens, the brewer frequently worries that the wort will be contaminated.
A person’s hands are not sterile. They have traces of bacteria and wild yeast from every surface that the person has recently touched. It is logical to worry that touching wort will lead to contamination. However, in practice, this is not automatic. I, and many other homebrewers, have accidentally come in contact with my wort and still produced beer that was free of noticeable contamination. In general, you should try to avoid this contact. However, it does not automatically lead to contaminated beer.
Although a person’s hands typically harbor a wide range of bacteria, most of these are not of a type that can grow strongly in wort. And, for the vast majority of microorganisms, an alcohol content of even a couple percents by volume is fatal. If your brew day otherwise went well, and you pitched an optimal number of healthy yeast, you may not encounter any problems. This is most likely because the yeast will simply outcompete whatever contaminants were on your hands.
My fermentation hasn’t started yet. Should I be worried?
It depends. If you chilled the wort adequately, aerated well, pitched a healthy amount of yeast, and are holding the wort in a temperature range that is appropriate for your yeast strain, you probably have little need to worry. Sometimes, a fermentation will simply take a little longer to start than usual. Also, different strains may vary with regards to their start times.
On the other hand, if you pitched an inadequate amount of yeast, there maybe reason to worry. Lower pitching rates lead to slower start times, increasing the potential for wort contaminants to take hold. Likewise, if you did anything that could stun the yeast — for example, heat shocking it — there may be reason to worry.
The smell coming from my fermentation lock seems odd. Should I be worried?
Probably not. Brewers yeast gives off a variety of odors as it ferments. These vary by strain and under different environmental conditions. Most fermentations produce some type of undesirable smell at some point in the fermentation process. These smells, which includes sulfury odors, phenolic odors, and other “off” aromas, are not present in the final beer.
If you used one strain of yeast frequently, and were aware of the aromas it produced during fermentation, a strange odor might be worrisome. However, if you don’t have experience with a particular yeast strain, whatever you are smelling from an airlock is probably normal.
There’s something floating in my fermenting beer. Should I be worried?
Probably not. Different strains of yeast look different as they ferment. Some produce a cloudy wort, while others clump together and look almost like a lava lamp. Occasionally, a little “colony” of yeast will float on top of the wort for a while after primary fermentation has finished. Unless you have other reasons to suspect that your beer might be contaminated, odd looking “floaties” are likely just yeast.
I broke a hydrometer/thermometer in my wort/beer. Should I be worried?
Maybe. Some hydrometers use lead to weight the instrument. Likewise, some thermometers are filled with mercury. Although the contact time with these metals maybe very short, both are very toxic. The prudent thing to do would be to dispose of any wort that has contacted lead or mercury.
In the case of a hydrometer with a non-toxic weight, or a thermometer filled with colored alcohol, the biggest threat would be broken glass. Carefully racking the beer to another vessel should leave all the large shards of glass behind. Have the wort flow through a fine mesh strainer to catch any smaller pieces. If the breakage is in beer, you’ll have to resort to a plate filter to remove the smaller pieces of glass.