6 Common Homebrew Myths with Denny Conn

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Common Homebrew Myths

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It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness…

Although Charles Dickens was talking about the French Revolution when he wrote those words, you’d almost think that he was talking about the flow of homebrewing information today. We have unprecedented access to homebrewing information and ingredients, which is a wonderful thing. But at the same time, we almost have an overload of information, and as anyone who has ever tried to hit every booth at Homebrew Con Club Night can tell you, it’s possible to have too much of a good thing!

One of the problems with all of this information is that much of it isn’t applicable to what we do, is questionable, or is simply wrong. I’ve spent a lot of my brewing time over the last 19 years and 500+ batches trying to figure out what’s true, what isn’t, and most importantly, what matters to homebrewers.

Let’s start by looking at where myths come from. The most common source seems to be homebrewing literature, coupled with word of mouth. Someone will write something they’ve heard in a book. That makes it “fact,” and it gets repeated down the line. The repetition gives it even more credence: “Everybody knows that’s true! It was in a book!” It could be that the misinformation appears true because someone misunderstands an underlying principle and attributes a particular effect to the wrong cause. Or it could be because no one has ever tested the concept to determine its validity or applicability to homebrewers.

Some myths start with commercial brewers whose concerns are quite different than those of most homebrewers. Others simply come down to a difference of opinion. And then there are myths that are directly contradicted by common brewing practices, but for some reason, people don’t connect them.

Here’s my list of the top six myths and misunderstandings that are common in the homebrew world.

Sparge Temperature

Ever since I started brewing, it has been taken as fact that using sparge water over 170° F (77° C) will extract harsh tannins from the grain and cause astringency in your beer. You still hear this frequently on forums and in books. But it seems to overlook one little thing: the decoction mash.

Decoction mashing has been around for centuries and is still used by some homebrewers today, many of whom win awards for beers made using the technique. Decoction mashing is done by removing a portion of the mash and boiling it before returning it to the mash tun. The last time I checked, boiling is hotter than 170° F (77° C)!  So, why does this technique make award-winning beer instead of a harsh, astringent mess? Because of pH.

If the pH is low enough, any tannins you may extract will actually enhance flavor rather than cause harshness and astringency. The magic number seems to be a pH of 6.  If you keep your pH well below that, the temperature of your sparge water really won’t matter. For the last 15 years I’ve been using sparge water in the 185–190° F (85–88° C) range and have no issues with tannins from the grain whatsoever. That’s because with my water supply and batch sparge technique, the pH of my grain stays well below 6, even without treating the sparge water with acid to lower the pH. Whether that exact method works for you will depend on your own water, although batch sparging does limit pH rise in the sparge. In traditional continuous (fly) sparging, you continually dilute the pH buffering ability of the grain, so it’s likely you’ll need to treat your water to maintain proper pH. Even in batch sparging, if you have extreme water, you may need to do some adjustment. But once you do, you have a lot more leeway with sparge temperature.

homebrew sparge

Another common misconception is that sparging with hotter water dilutes the sugar in the grain more, making it less viscous so it flows more easily and increases efficiency. Unfortunately, physics doesn’t seem to work like that. There’s a thing called the “limit of solubility,” which determines how much sugar can be dissolved in a liquid at a given temperature. Sugar solubility is not an issue in the mash or sparge. There is no solid sugar to be dissolved during the sparge, since the sugar is all in solution when it is created. The solubility of maltose in water at mash temperatures is about 66.7 % by weight (Maltose dissolves in water at a 2:1 ratio by weight—1 lb. maltose in 2 lb. water, 2 kg maltose in 4 kg water, and so on; reference), which is equivalent to a specific gravity (SG) in excess of 1.300. So unless the SG of your wort is over 1.300, there is no advantage to using hotter water to dissolve the sugars. Kai Troster has done experiments showing that even using cool (60° F/16° C) water to sparge will not adversely affect efficiency or beer quality, as has Ray Found of Brulosphy.com. I have also tested this repeatedly with the same results.

Some people have noted an increase in extraction by using hot sparge water and attributed it to the sugars being more soluble. In all likelihood, what they’re seeing is the last little bit of starch conversion happening due to the increased temperature. So, while sparging with hotter water may increase your efficiency, it’s not due to increased solubility. It’s due to increased conversion efficiency.

But let’s get real here. Aside from the curiosity of demonstrating that hot sparge water doesn’t matter, or as an emergency technique when for some reason you can’t heat the water, there’s no real advantage to using cool sparge water. You have to heat the wort to a boil anyway, and hotter water will get you there more quickly.

Hot Side Aeration (HSA)

There, I said it. Three of the most controversial words in homebrewing! This seems to be one of those things that originated in the commercial brewing world and got passed on to homebrewers. Twenty years ago, the conventional wisdom was to carefully avoid aerating wort when it was above 85° F (29° C). The rap was that it would accelerate staling, which can cause wet cardboard, metallic and, strangely, caramel flavors in your beer. The only time oxygen was supposedly not harmful was when the wort was chilled and ready for yeast. So homebrewers were careful to the point of paranoia.

But a funny thing happened when almost no one actually noticed the effects of hot side aeration on their homebrew. Commercial brewers were, and still are, usually careful to avoid it, although there a couple of notable exceptions. But at the homebrew level it just didn’t seem to happen. Luminaries like Dr. Charlie Bamforth said that HSA was not a problem. Eventually he and Randy Mosher, among others, reached the conclusion that it could be a problem, but at the homebrew level it was unlikely to rear its head and there were far more important things to worry about. A Brulosophy Exbeeriment found no difference between beers that had minimal hot side oxygen exposure and ones that had been heavily aerated on purpose.

So, what’s the takeaway here? My point of view is that hot side aeration is easy enough to avoid that you should try to not do it. That can be as simple as not pouring hot wort or using a piece of tubing when you collect mash runoff in the kettle. We all know that oxygen is the enemy of beer, so why not try to avoid it anywhere you can? But at the same time, don’t freak out about it.

Olive Oil

A few years ago, a guy named Grady Hull who worked at New Belgium Brewing wrote a paper about the possibility of using olive oil, rather than conventional aeration, to stimulate yeast growth. In a nutshell, the theory is that yeast cells use O2 to synthesize ergosterols, which keep cell walls flexible and ease the budding process for yeast cell growth. The thinking with olive oil is that you “cut out the middleman.” You add the oil, which does the same thing to cell walls. Now, homebrewers being homebrewers, they jumped on this technique as an easy, inexpensive alternative to aerating wort. Unfortunately, they didn’t seem to pay attention to what Grady was really doing: using olive oil for yeast storage, not propagation in the fermenter. They also didn’t account for the infinitesimally small amount of olive oil needed. Most homebrewers who tried it reported things like “well, it didn’t hurt.” Neither does doing the Chicken Dance around your wort!

At Experimental Brewing, we decided to test the effectiveness of using olive oil in place of aeration. Four different brewers each split a batch of beer using olive oil “aeration” on one half and doing no aeration at all on the other half. The idea was to see the most dramatic difference possible. If olive oil “aeration” worked, we should see a marked difference between that and doing absolutely no aeration at all. The four brewers arranged blind triangle tastings with a total of 47 tasters. The results? Most tasters found no difference whatsoever in beer flavor. The brewers reported no differences in fermentation performance. The takeaway was that using olive oil for aeration was equivalent to doing no aeration at all. You can see the results for yourself at ExperimentalBrew.com.

Save your olive oil for salads!

Fly Sparging vs. Batch Sparging Efficiency

Batch Sparging VS Fly Sparging: Which is Best?

You will frequently hear people say that fly sparging yields better extraction efficiency than batch sparging. That’s true… in a perfect world! I don’t know about you, but I don’t live in a perfect world.

What I mean is that if you have a perfectly designed fly sparging system, and if you execute your process perfectly, theoretically you will achieve greater extraction by fly sparging. But those ifs are the problem. In reality, batch sparging will yield at least as high, if not higher, efficiency than fly sparging. When you batch sparge, variables like lauter tun design and sparge technique are removed from the process. In the real world, efficiency in excess of 80 to 85 percent is possible with batch sparging—pretty much the same as fly sparging. The decision of which to use should be based on your preferences and equipment choices, not efficiency concerns.

Fermentation Temperature

When you buy a package of yeast or look at a yeast company’s website, you see a list of recommended temperature ranges for each yeast strain. What a lot of homebrewers don’t realize is that those are only vague guidelines, not hard-and-fast rules! They often recommend temperatures higher than those that most homebrewers prefer. Yeast fermentation temperature can have a large impact on beer flavor, and in general, the warmer you ferment, the more impact it has. But that impact isn’t always desirable. As we all know, esters tend to increase at warmer temperatures. If you get too warm, the dreaded fusel alcohols can become a problem.

In general, most homebrewers prefer to at least begin fermentation at temperatures lower than the recommendations. Most esters and fusels are formed during the first 72 to 96 hours of fermentation. After that, you can safely raise the temperature to make the yeast more active and ensure complete fermentation.

Another myth floating around is to always start fermentation of Belgian styles at higher than normal temperatures. While some Belgian breweries do that, it is far more common for them to follow the fermentation schedule I described above, starting cool and finishing warmer.

My general recommendation would be to start your fermentation at, or a bit below, the lowest temperature recommended for the yeast. The exothermic reaction from fermentation will raise the temperature a bit, and after three or four days, you can safely let the fermentation temperature rise. If you find you’re not getting enough yeast character like that, just start a bit warmer the next time.

Along the same lines, the conventional wisdom is that lagers take a long time, sometimes months, at a low fermentation temperature. But there’s an old lager fermentation method, also used by commercial brewers, that has begun making itself known in the homebrew world. Using this method, you can have a lager in your glass in as little as two weeks after brewing it. Mike “Tasty” McDole was one of the first homebrewers to rediscover this method and begin talking about it. Since then, many of us have started using this method.

You can find more about it online or in the book Homebrew All-Stars (shameless plug), but the basic idea is to start your fermentation at 55° F (13° C). When the gravity drops 50 percent of the way to its expected terminal value, raise the temperature to 58° F (14° C). When it gets 75% of the way there, raise the temperature to 62° F (17° C). And then when it reaches 90%, raise to 66° F (19° C) and hold until the beer reaches your expected final gravity. You can have your delicious lager in two weeks rather than two months!

Liquid vs. Dry Yeast

This is another thing that has changed a lot over the last 20 years, but for some reason the old saw persists that liquid yeast is always better than dry yeast. The “always” in there should be a red flag! Years back, production techniques for dry yeasts were less sophisticated than they are today, and packets might have been lifeless or contaminated by the time homebrewers purchased and used them. These days, I’m happy to say things are much better, and there are some great dry yeasts out there. You can make your selection based on flavor, performance, and your preferred methods rather than simply whether the yeast is dry or liquid. A couple of my favorite lager yeasts are dry (Fermentis Saflager W-34/70 and S-189). Try a few dry strains and see what you think of them. I think you’ll be pleasantly surprised.

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So, there you have it: my partial list of “homebrew myths.” There are certainly more, and you may have run across a few yourself. Post ‘em below in the comments, and let’s get rolling on Homebrew Mythbusters!

Denny Conn is an American Homebrewers Association Governing Committee member, co-founder of the Experimental Brewing podcast, and author of Experimental Homebrewing and Homebrew All-Stars. Find him on the AHA Forum as ‘denny.’

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