Extract Twang

Posted on 06.14.08 9:32PM under Brewing, Extract, Troubleshooting

BanjoOn the homebrewing forums you read a lot about “extract twang”. It’s supposed to be a certain type of off flavor that comes as a result of using extracts in your homebrewing. Many say it’s a myth. But when you taste enough homebrewed beers that have that certain “something” to them, you start to believe in extract twang. Logic tells you it must be a process issue, but your gut replies, “no, it’s the extract twang.” And you just move on with your life. Here’s an exploration of some potential causes of so-called “extract twang.”

About a month ago, I made an extract batch for the first time in a while. Last time I made an extract batch it was a 1.104 monster, and it ended up imperfect in many ways. Extract twang would have been the least of my issues. This beer was flat and underattenuated, and it did have an extract twang, or something. It was not good. Since then, I’ve been all grain every time. Until last time.

I wanted to make an easy to execute beer to bring to people at work. So I chose an extract recipe based loosely on Sierra Nevada Pale Ale. This beer came out great. I don’t taste any extract twang at all. So it got me wondering about that ol’ twang. Here are my thoughts on some of the main potential causes and how they can be avoided.

1. Yeast Handling

Problem: Inadequate oxygen in the wort is a real problem for yeast. They need oxygen to do their yeasty thing. Specifically, they prefer oxygen dissolved in the wort. One might say that they require it for their aerobic activity that consumes sugar and produces alcohol and CO2. Yeast also need to be pitched in the proper amount for the gravity and quantity of wort they’re tasked with transforming.

Solution: My procedure is not complex and doesn’t take anything fancy. I use dry yeast. US-05 right out of the packet. Just sanitize the packet and the scissors and cut and pour onto aerated wort. To get dissolved oxygen into the wort, I use the same method I’ve always used since my first batch. I pour the wort back and forth a few times between the kettle and the fermenter. Basically it’s about five times or until there’s so much foam that I risk a spill (actually I always spill at least a little foam).

2. Sanitation

Problem: Everything has got to be sanitized for this thing to work. Before things can be sanitized, they must be clean. Often it requires two products: one to clean and a second to sanitize.

IodophorSolution: I clean with a dish sponge and dish soap. For sanitation, I use Iodophor. Two tablespoons in a bucket full of water is about enough for sanitation. Most times I just eyeball it. A friend of mine once told me, “If it looks like iced tea, it’s good to go.” And that seems to be true. I err on the side of caution, and often add a little more Iodophor than I think I’ll need. To me, the most important part is using a no-rinse sanitizer and then not rinsing. If you rinse with unsanitized tap water, then there’s no point in sanitizing in the first place.

3. Ingredient Freshness

Problem: How old is that extract? How has it been stored? Stale extract could provide some strange and unexpected flavors in your beer.

Solution: Try to get fresh extract. Store it in your fridge once you buy it. I got my extract from a small local shop that may or may not turn over a lot of extract. I kept it in my fridge for a month or so before using it. And I guess it was fresh enough.

4. Adding the Extract

Problem: Extract needs to be dissolved into the water or wort. Fire can burn undissolved extract and cause unexpected flavors.

Solution: Make sure you take the kettle off the heat before you add and stir in the extract. I have added it into a kettle right on the flames before and got a burned tasting beer. Fortunately for me, it turned out to fit in pretty nicely with the overall flavor profile, but many beers would not benefit from a burned taste. But is a burned flavor really extract twang?

5. Concentrated Boil

Problem: Many brewers have only a 20-quart kettle to work with. This only enables low volume boils of about three gallons of wort. This results in a high gravity boil, which reduces hop utilization among other factors. It also requires adding water after the boil to get your full volume of beer. This top off water must be sanitized, too.

Solution: I actually boil on a 30-quart aluminum turkey fryer with propane in my garage with all the doors open. This enables full volume boils, and generally simplifies things. I think that it’s possible that there’s some way that the typical stovetop concentrated low-volume, high-gravity boil can contribute to unexpected flavors. A way to get around this with your existing setup is to add half the extract late in the boil (with 15 minutes to go, along with your Irish Moss). Just make sure you take the kettle off the heat to add the extract. Regarding top off water, you must boil it to sanitize it, just like you did with your wort. Adding unsanitized water to fresh wort is asking for trouble.

Bonus Solution: If you can only boil three gallons of wort, you could make smaller batches. Pick a size based on your equipment. With a 20-quart pot, for example, you might be able to manage a 2.5 gallon batch. YMMV.

6. Cooling the Wort

Problem: Cooling wort is a magnet for wild yeast and other uninvited guests. You want to get that stuff cooled down as quickly as possible so you can pitch yeast and close it up for fermentation.

Immersion ChillerSolution: The kitchen sink with an ice bath does an OK job of cooling wort, but this is one case where a piece of equipment makes a huge difference. An immersion chiller is a coil of copper that makes chilling wort a snap. It goes into the wort for fifteen minutes of the boil to sanitize it, and then you run cold tap water through it after the boil to cool the wort. The cold tap water exchanges heat with the hot wort and the end result is a room temperature wort in about 20 minutes – no messing with ice or anything – just set it and forget it. I have the chiller pictured to the side here. One maintenance item is to tighten the clamps that hold the plastic hose to the copper every brew session. The heat from the kettle causes expansion and softening of materials and it has to be tightened to prevent leaks. FYI.

7. Fermentation

Problem: Yeast don’t like change. They work best in a very stable environment. The spare closet experiences drastic temperature swings sometimes, especially in the hot sunny summer months. Without a stable temperature, the yeast can get way too hot during fermentation and then crash once the exothermic growth phase is done. This causes excessive esters from the heat, and potentially incomplete fermentations from the crash.

Fermentation Temperature ControlSolution: This is another equipment-based solution. I believe it’s essential to control fermentation temperatures. Many talk about using a water bath around the fermenter, which creates a larger thermal mass and enables you can use icewater bottles to decrease the temperature as needed. It’s often called a swamp cooler. I personally like the used fridge with a temperature controller solution. It costs a little more, but it requires a lot less worry and babysitting. I already have kids, I don’t need to be worried about changing my ice bottles to ensure the fermenting wort’s comfortable at 65 degrees. That said, any way to keep the temperature from rising to high in early fermentation and to keep it as warm as you want it for later fermentation will work. Feel free to share your creative fermentation temperature control methodologies.


Do you have any additional methods to prevent off flavors in your brewing? Did I miss a factor that you found to make a difference for you? Are you wondering if something that you’re doing is hurting your beer? Post a comment!

So far my conclusion is that there are a lot more ways to screw up an all grain batch of beer than there are ways to screw up an extract batch. Extract twang is preventable. Einstein says (roughly) “A clever person solves a problem. A wise person avoids it.” Hopefully I’ve made you a little bit wiser today. And perhaps a little more clever, too. You can make a defect-free extract beer if you have a solid brewing procedure and the right equipment.

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