Recovering from Brew Day Mishaps
Someday, inevitably, something will go horribly wrong with your brew day. Not in the, “My burner set the house on fire” or “I have a kettle’s worth of boiling sugar water flooding my floor” wrong. Although this sort of catastrophe can happen, your disaster is more likely to be something smaller. Think more, “Is my wort/beer ruined?” Some brew day errors can be fixed, some happy accidents result in new beer recipes, and some, well, some go down the drain.
This article will detail some of the problems that can arise during a brew day, some options to correct the problem, and whether the batch can be saved. However, before we get into the problems, let’s rewind and discuss briefly what should have been done to prevent a problem in the first place. Each of the issues we will cover is preventable, and a few extra moments of planning and preparation is far easier than trying to fix a problem after it arises.
The best way to avoid errors is to follow a consistent process. Until that process becomes second nature, use a checklist. If you are checking off each step as you do it, then you won’t have to worry about these types of errors. That checklist should begin with things that must be looked at prior to the start of your brew day (ingredients on hand, propane tank full, available fermenter, etc.) and continue on through the brew day and end with cleanup. In addition to checklists; timers are your friend, preferably with loud alarms. Multiple kettle additions? Set a timer for each so you don’t miss any! Need to get your sparge water to optimal temperature when the mash is over? Set an alarm for when you need to start heating it. Remember, prevention is always preferable to remediation.
Follow that previous advice, and the majority of mishaps that may come up during the brew day should be minimized. Still, issues may sometimes still arise, which is where the meat of this story takes hold.
Should something go wrong, it is helpful to have a “homebrew first aid kit” on hand. I list the contents of my first aid kit below, but yours may differ depending on your brewing system/style. After that, we’ll review some potential brewing issues that may arise, ways they may be addressed, and impact it could have on the resulting beer.
Your Brew Day First Aid Kit
Having the following items on hand can save a brew day:
• Extra brewing liquor.
• Dried or liquid malt extract, or other source of sugar.
• Extra yeast, particularly a relatively neutral yeast strain. Dry yeast is ideal as it stores longer.
• A supply of versatile, neutral bittering hops and perhaps a favorite flavor hop.
• A supply of base malt such as brewer’s malt, Pilsner, or pale ale.
• Frozen water bottles, ice, or cold brewing liquor.
• Basic tools such as a screwdriver, adjustable wrench, and rubber mallet.
• Cleaning supplies, including a mop and a mop bucket.
• Sanitizer concentrate or household bleach.
• (If you use propane) an extra propane tank, a windbreak, or an alternate heat source.
You Bought the Wrong Ingredients, or the Homebrew Shop Didn’t Have What You Needed
Consider how much of a difference the ingredients you bought or that are available will make in your beer’s outcome. If you bought American Pilsner malt instead of German, the difference will not affect your beer’s drinkability. However, if you bought Munich malt instead of Pilsner and roll with the error, subbing Munich for Pilsner malt will significantly change your beer’s color and flavor. Specialty malts, like roasted barley or chocolate malt, have even more of an impact on the beer’s flavor. Your options, particularly if you crushed the malt at the store, are either brew the beer as-is, change course and brew a different beer that fits the ingredients you sourced, or replace the ingredients. If you kept the grains separate, you may be able to replace the incorrect malt with something closer that you have on hand or obtain the correct malts, keeping the incorrect ingredients for another brew. This is a good place to point out that, particularly if you brew regularly and have the space for it, having an inventory of different ingredients on hand, stored properly, is always a good idea.
You Did Not Complete Some Aspect of Brew Day Preparation
The severity of the problem depends on what you forgot to do. Forgetting to make a starter is one possibility. Key to solving it is to ensure you pitch enough yeast, either by delaying the brew day until you can make a starter or pitching multiple packages of yeast instead of a starter. If you use reverse osmosis (RO) water and didn’t start collecting water early, it may take some time to collect the amount you need. You may consider diluting dechlorinated tap water with the RO water you have and recalculating the brewing salt additions. If you forgot to add salts or acids to your water, simply add them to the mash tun and stir. If you failed to calibrate an instrument such as a pH meter, calibrate it and repeat your measurement.
Mashing Errors
Most mash errors involve temperature or water volume. If your mash temperature is off, use your judgment: Will a degree or two of deviation from your planned mash temperature make a huge difference in your final beer? If you are trying to reproduce a beer for a competition, the small difference might be important. Before I could add heat directly to my mash, if my temperature was off by less than 2° F (1 °C), I didn’t worry about it. Now, with a recirculating immersion mash system (RIMS), I get antsy over 0.5 °F (0.3 °C). Others don’t sweat it if it is within 5 °F (2.5 °C) of your target. Everything is relative.
Focusing on the ratio of water-to-malt and the temperatures of these two components to avoid issues should be a part of your routine, and brewing software will get you the correct amounts. However, if you overlooked this step and have a mash that is too hot, then cooling your mash is easy. You can add cool water or ice (deduct the water from your sparge water to avoid producing too much wort or losing efficiency by leaving wort in the mash tun). Brewing software can calculate the amount of water needed at a given temperature to cool the mash, or you can guess how much water or ice to add, stir, then measure the mash temperature. An option that does not affect water volumes is to use frozen bottles of water to cool the mash. Throw them in and then take them out when you reach the temperature you desire.
Adding heat is more complex for those using passive temperature systems such as a cooler converted to a mash-lauter tun. You may add hot water (deduct the amount from the sparge) or perform a single decoction by removing part of the mash, boiling it, and returning it to the mash tun. Your brewing software can calculate how much to decoct for a given temperature increase. A thin mash works fine for this purpose.
Incorrect measurement of water volumes can cause issues with mash thickness and temperature. Thickening a thin mash is generally unnecessary but an extremely thin mash may not convert well. Add hot or cold water if you need to adjust the mash temperature. Since incorrect water volume is a measurement error, you may not need to deduct the additional water from the sparge.
Many brewers predict and control mash pH to ensure repeatability, reliability, and good quality beer. Brewing software calculates the salt and acid additions for us based on our water report, water volume, and the grist information; and sometimes it goes wrong. Correction is relatively simple: If the pH is too high, add acid, if it is too low, add a base, if it’s within +/- 0.1, smile and keep brewing. We can calculate the amount or we can add a milliliter or two of concentrated acid (or a gram or two of base), stir and re-measure the pH until close enough. Given the speed with which modern malts convert, guessing might be a better approach than the time it takes for calculation. Keep in mind that pH doesn’t settle until late in the mash, so you may be chasing your tail if you try to correct it early in the mash. When mash pH is off, Denny Conn recommends recording it, continuing on the same path and making adjustments in the next brew day when corrections can more easily occur beforehand.
The worst error during mashing is a stuck mash. Highly adjunct-laden mashes can set up like a bowl of Cream of Wheat. Stuck mashes are best avoided by using rice hulls, a glucan rest, or beta glucanase. If your mash sticks, here are some things to try: Use a knife or the edge of a spoon to cut a crosshatch pattern in the surface of the grain bed. Backpressure from blowing into the run-off hose can sometimes free a mash. Heating the mash a few degrees may get things running, or stir the mash and vorlauf again. If you have rice hulls on hand, stir them into the mash to loosen it.
Error Made Measuring Ingredients
Too little or too much water will lead to mash temperature errors, assuming the strike temperature is correct. If you incorrectly measured grain, the mash temperature could also be an indication, assuming you added the water at your intended strike temperature. Too much malt results in a higher original gravity (OG), too little, in a lower one. Correct high OG by diluting the wort with water, either in the mash tun, boil kettle, or even later. Sugars or dried malt extract (DME) can correct a low OG; if you have extract in your first aid kit then you can correct the problem during the boil. Remember to recalculate your hop additions if you change the boil gravity.
An error measuring specialty grains may not be recoverable. You will not get your intended results, which is not always a bad thing! Too much roasted grain makes your schwarzbier a porter, too much crystal results in a sweet, thick brew. You may like the results. One of the best American porters I’ve ever made was the result of over-sparging.
Errors measuring salts or acids may result in a mash that does not settle at the proper pH. If your measured pH is outside of your desired range, it can be adjusted using acids or bases. Specialty ingredients such as spices tend to be very strongly flavored so use caution when adjusting. Likewise, some sugars such as molasses have very strong flavors. Use discretion: You can always add sugars to the boil or the fermenter, bearing in mind the amount of extract in your wort will affect hop isomerization during the boil.
Boil Gravity or Volume is Not Correct
If you corrected water volumes or the amount of grain earlier in the process or your grain crush was too fine or coarse, your original gravity may be off, your wort volume may be off, or both. It is the brewer’s decision if a correction is needed. If the volume is off but the gravity is correct, I would not adjust. Be sure to check the temperature of your sample, high temperature samples will give you a low gravity reading.
High gravity is adjusted by dilution with water or shortening the boil. Low gravity is adjusted by adding sugar or DME or extending the boil. Let gravity be your guide: Too little wort at the correct gravity is preferable to attempting to adjust both volume and gravity.
Insufficient Heat to Boil the Wort
Many brewers boil their wort using a high output propane burner and have few problems boiling wort, that is until they run out of propane in the middle of a brew. Or until the flame blows out in the middle of a boil. Having spare propane on hand and knowing how to use your boil-off rate to calculate the remaining boil time are the best ways to mitigate issues with empty propane tanks or strong gusts of wind. If your flame has gone out, you can calculate the time remaining if you know your boil-off rate. Turn the propane back on (or get another tank) and finish the boil as planned.
Scorching
If your propane burner runs hot you can scorch the wort on the bottom of the kettle. Likewise, if you boil a pot or kettle dry, the wort can scorch. Allowing a grain bag to contact the bottom of the kettle can also result in scorching (and burning a hole in the bag). Scorched wort generally does not make good beer, so it is a judgment call whether to ferment the wort or dump it. Cleaning a scorched vessel requires elbow grease and good cleaners. I’ve had good luck with Barkeeper’s Friend, stainless steel scrubbies, and lots of hot water. A stainless-steel plate called a flame tamer may help if your burner runs hot.
Issues with Hops
Forgetting a bittering charge is easy to fix if caught soon enough. Bring the wort volume back up to the starting point with water and restart the boil timer. Alternately, recalculate the amount of hops you need using the remaining boil time. If you do not have enough of the original bittering hop, calculate another addition of neutral hops from your first aid kit. The same logic may be used with flavor hop charges, just return the wort to the volume it should have been at the time of the addition and resume the boil. Use your brewing software to calculate the correct amounts for the modified hop charges.
A possible issue if you use leaf hops is clogging an intake or an outlet valve. Use backpressure to free the clog. Use a muslin grain bag, hop spider, or other screen to keep the hops from clogging things.
Wort volume or gravity is not as predicted
At the homebrew scale, many processes are not consistent. Boil-off rate is one. Altitude, humidity, and ambient temperature are some of the most common factors that can affect boil rate. I generally will not correct a volume error of less than a half-gallon (2 L) or a gravity error of +/- 2 points; your thresholds are your choice. If your gravity is too high, you can correct by adding water. If adding water, it should be dechlorinated then boiled, or the wort should remain above the pasteurization temperature, at minimum one minute above 160 °F (71 °C). If adding water to chilled wort, it should be dechlorinated, boiled, and cooled. If your gravity is too low, you may add sugar or malt extract to bring the gravity up, add directly if the wort is hot enough to pasteurize the addition, or make a syrup and boil it for a few minutes otherwise. If using a syrup, do not forget to add the volume of the water in the syrup to the volume of water in the wort calculation.
To determine how much water, sugar, malt extract, or other sources of extract you need to adjust your wort’s gravity — brewing software makes this process relatively easy, but for old school brewers the math can be done by hand.
Final pH is Too Low or Too High
The wort going into the fermenter should have a pH of 5.0–5.2 according to this article: byo.com/article/the-principles-of-ph/. Adding Whirlfloc, a common kettle fining, raises pH due to the baking soda it contains. If your final pH is too high, add acid. I prefer lactic acid since it is a natural component in beer, you may choose a different acid. I’ve found that the wort seldom has low pH but if that is an issue, adding a base such as baking soda will bring the pH up. It’s your call on pasteurization, both concentrated acids and bases are very hostile environments for microorganisms.
Sanitation Issues
Anything that touches wort once it has cooled below about 160 °F (71 °C) must be sanitized. Sanitization kills most of the microorganisms on a surface. For sanitization to work, the surface must be clean. You may not notice a speck of dried wort or a bit of film, the problem only becomes apparent after fermentation. If you forgot to sanitize something, after it has made contact with the wort, it is too late unless you can bring the wort back above 160 °F (71 °C). But an infection is not inevitable if you have kept everything squeaky clean. Time will tell if a sanitation issue turns the batch into a dumper as there is no fix once the wort begins to turn.
Pitch and Yeast Issues
The worst possible pitch error is pitching into hot wort. If the wort is below 95 °F (35 °C), the yeast will likely survive but may produce excessive esters. If the wort was above the recommended temperature for a given strain, it is probably best to pitch new yeast after cooling. Yeast health is adversely affected by lack of oxygen if using a liquid yeast or a starter, but pure oxygen is toxic to yeast. If you have forgotten to aerate/oxygenate when using liquid yeast, you can aerate with a pump and an air stone, stir vigorously, or shake the fermenter to dissolve air into the wort. Dry yeast is packaged with the glycogen and sterols it needs for healthy fermentation, so oxygenation is generally not needed. If fermentation is not visible in a couple of days (for most strains) it won’t hurt to pitch more yeast.
Fermentation Issues
Your fermentation temperature control may fail. If the beer gets too warm, you risk excessive fruity esters, too cold and you could freeze the beer, damaging yeast cells. In either case, if it happens, there’s not much you can do other than adjust the temperature back to where it should be and let fermentation continue.
One particularly nasty fermentation issue is the dreaded clogged blowoff tube or airlock. The problem results in a rather nasty cleanup and loss of some beer. Whatever beer remains behind in the fermenter is likely still good. Avoid the issue by leaving adequate headspace in the fermenter or by using a blowoff tube during the most vigorous fermentation. When using a blowoff tube, suck-back of whatever fluid you use can be an issue when the wort must be cooled after the airlock or blowoff tube are affixed to the fermenter. To prevent suck-back, while the wort is cooling, crimp aluminum foil or use plastic wrap over the empty airlock or end of the blowoff tube then add liquid once the beer has cooled.
A stuck fermentation happens when the yeast stops fermenting before all fermentable sugars have been consumed. The first thing to determine is whether the fermentation is stuck. Check your final gravity against the predicted target. If the difference between measured and predicted final gravity is large enough, try swirling or stirring the wort to get the yeast back into suspension. You might try raising the temperature a few degrees. A fresh pitch of high-gravity yeast or actively fermenting wort can also bring the gravity down. But if the yeast is done, a point or two reduction of gravity is about all you can expect.
Packaging Issues
We usually either bottle or keg our beer. Bottling can introduce spoilage bacteria and oxygen, too much or too little priming sugar leads to over- or under-carbonation. If the bottles do not carbonate at all, either the yeast died, or you forgot priming sugar. Add measured amounts of pasteurized sugar syrup or granulated sugar to the bottles, recap, and see if anything happens. If not, add a few grains of dried yeast to each bottle. By this time, you may have introduced enough oxygen to spoil the beer, but you can find out what happened.
Extreme over-carbonation or infection can lead to bottle bombs and gushers. If you have gushers, chill the bottles as cold as possible and taste the beer. If there are no off-flavors, you can uncap the bottles, let them set for a while, then recap. How long is guesswork, there’s no science to this. If you have off-flavors, you must decide if the beer is drinkable. If you keep it, chill the beer as cool as possible to retard further bacterial growth and control gushers. If not, chill the beer as cool as possible to reduce the chance of an exploding bottle, uncap carefully and drain. If you have had a bottle bomb in a batch, chill the remaining bottles as cold as possible, even freezing, then carefully uncap and dump the batch. Saving a beer is not worth an eye.
The most common kegging issues are over-carbonation or under-carbonation. To fix under-carbonation, turn up the gas pressure. To fix over-carbonation, shut off or disconnect the gas and burp the keg a few times. You can also spring a leak somewhere in the system and lose all your gas. Obtain or use a full bottle of CO2 and reconnect everything. Use soapy water to find the leak and fix it to avoid repeating the problem.
Conclusion
Inevitably, if you brew long enough, you will have an opportunity to save a batch. Problems encountered after mashing tend to be less forgiving; however, a sanitation issue is not recoverable and a bottle bomb results in lost beer and potentially dangerous flying glass shards. But some of the errors on the hot side can be overcome. Corrections may result in a different beer than you had planned, and others may result in a drain pour. Using your homebrew first aid kit and brewing skills, document what went wrong and plan to avoid it and you can save most batches. And keep good notes, you may have stumbled upon your new favorite beer.
