by Todd Steele (Brewing Techniques)
With the abundance of specialty wheat malts and the availability of natural lautering aids, brewing with 100% wheat grists is not only possible, it is easy, and it is opening new vistas for both home and commercial craft brewers.
Barley has clearly become the grain of choice for brewers. Common wisdom holds that its properties lend themselves to brewing more readily than do those of other grains. Wheat, meanwhile, has gained a reputation as a grain that is difficult to work with, a grain that is best used as a minor player in the overall barley-based grain bill. This article challenges that assumption.
It should come as no surprise that wheat, as one of the first grasses to be cultivated by man, was an ingredient in some of the world’s first beers. The Babylonians, for example, used wheat in their primitive beers, and according to Martin Hurlimann, beer historian and owner of Brauerei Hurlimann in Zurich, Switzerland, the Babylonians made a lot of wheat beer in the 400 years before their demise. Throughout history, various brewing cultures have kindled a fondness for wheat beers, the most notable, perhaps, being the Germans, with their rich tradition of Weissbiers, Hefeweizens, and Weissbocks. More recently in the United States, the microbrew revolutionaries have found wheat beer to be an easily approachable introductory beer for the general public, particularly American wheat beer, a distant cousin of its German ancestor, Hefeweizen. This pale and cloudy beer is mild in flavor and has little or no hop flavor or bitterness. To many, it is the first step into the wonderful world of hand-crafted beers.
Brewing with wheat offers the brewer opportunities to expand on existing styles or to create new ones. After noticing the number of specialty wheat malts available on the market, I began to toy with the idea of brewing a series of all-wheat beers. How would a beer brewed with no barley malt compare with a beer of the same style brewed with standard barley malt? What problems would be encountered and how could they be overcome? What about brewing a style that traditionally uses no wheat malt? Would the finished product be true to style, or would it push the envelope?
This article is the result of a project I undertook to answer some of these questions. The limited scope of this nonscientific project only scratches the surface of this intriguing subject. I hope that others will be prompted to do further experimentation with all-wheat beers.
One reason wheat has taken a back seat to barley is that it has no husk. Husks are a key element in creating a filter bed for successful lautering. Without husk material in the grain bed, the brewer can expect to have lautering problems. Traditional wheat beers therefore typically include a significant amount of barley malt to provide adequate filter bed material.
Another problem with wheat malt is the perception that it lacks the enzymes necessary for starch conversion. Traditional German wheat malts, for example, were typically undermodified, which produced fewer enzymes. Again, brewers offset this weakness by including barley malt in the grist. Wheat has a different protein makeup than barley and is usually associated with higher protein levels in general — traditionally necessitating protein rests to reduce hazing and to supply enough nutrients for the yeast.
Although these problems have presented real challenges in the past, today’s selection of wheat malts and the availability of natural lautering aids make them relics of the past. My experiments demonstrate that excellent beers can indeed be made with 100% wheat malt, with or without complicated techniques. With these commonly available raw materials, you, too, can push the style envelope and brew innovative all-wheat beers.
Managing wheat proteins: Most brewers believe that wheat malt is higher in protein than barley malt and thus likely to result in hazy beer. Depending on the variety, however, wheat is not necessarily higher in overall protein than barley, though wheat naturally contains relatively more of the higher molecular weight proteins that can cause haze. Depending on the beer you are brewing, this tendency to throw haze may be a problem; of course, when you’re brewing classic unfiltered wheat beers a bit of haze may be acceptable and expected.
Wheat’s protein content does have a positive side: the protein contributes to a thick, long-lasting head, which is one reason brewers may add a portion of wheat malt to some of their barley-based beers.
The first step in developing an all-wheat recipe is to find out the overall protein level of the malt you are using. The desired protein level for wheat, as for barley, is generally less than 12%. Many wheat malts are available in this range, though some are higher. (See the table, “Typical Specifications for Several Pale Wheat Malts.")
If you are very concerned about your beer’s clarity, the trick is to break down or remove the larger proteins without removing the medium-weight proteins that promote head retention. A protein rest in the 130s °F (55–59 °C) for 30 to 60 minutes should be sufficient. Alternately, any number of clarifying agents can be used to drop out the proteins that contribute to haze. Irish moss, for example, can be added during the last few minutes of the boil; gelatin, isinglass, Polyclar, or activated silica gel can be added to the finished beer in the secondary or at kegging. Filtering is still another option, but is not as selective as some of the other fining agents (that is, it may remove some desirable elements such as those responsible for a Weissbier’s clovey, estery flavor). Cold conditioning the beer at or near 34 °F (1 °C) for one to two weeks will also help reduce chill haze.
Ensuring sufficient FAN levels: Another potential problem related to undermodified malt and high protein levels (especially high levels of larger proteins) is that levels of free amino nitrogen (FAN) may be lower than desired. FAN is important for proper yeast metabolism. It’s a good idea to check the amount of soluble protein in the malt you’re considering using. A ratio of soluble protein to total protein (S/T) above 40% should indicate the presence of enough FAN for a good fermentation (see box, “Know Your Wheat,” for more information).
Many of the available wheat malts have sufficient FAN levels, but keep in mind that roasted specialty malts will likely contribute little FAN to the brew. If you know your malt is under-modified, a relatively short protein rest at around 122 °F (50 °C) can help break down smaller proteins to amino acids. If you’re not sure, add a good yeast nutrient during the last 15 minutes of the boil to help promote a vigorous fermentation. A protein rest in the temperature range that would increase the wort’s FAN content (below 130 °F [55 °C]) is not recommended when using well-modified malt because it may be detrimental to head retention and may actually negatively affect a beer’s maltiness.
Breaking down beta glucans: If you’re capable of doing a step mash, many brewers suggest that a beta glucan rest (at 95–104 °F [35–40 °C]) can be very helpful in barley or wheat to break down the starchy glucans that can increase the viscosity of the beer.
Eliminating stuck runoffs: The most annoying problem in brewing with wheat is the likelihood of a slow or stuck runoff. Because wheat malt has no husk to aid with the creation of a filter bed in the lauter tun, the brewer is rewarded with a large bucket of glue.
Luckily, the filtration problem is solvable with the addition of rice or oat hulls to the mash.* The hulls add no significant color, flavor, or fermentables to the mash, so they need not be considered in the creation of the grain bill. I successfully used a quantity equal to 10% of the grain volume, adding the hulls to the beginning of the mash and mixing them thoroughly with the grain. The only adjustment this technique calls for is in the mash water volume; calculate water requirements based on total grist volume (malt plus hulls).
The absence of hulls in wheat malt does provide an inherent benefit: you can sparge and recirculate longer with water at a higher temperature than normal without having to worry about leaching out astringent tannins from the husks. Sparge temperatures above about 170 °F (77 °C) are not recommended for barley, but wheat will tolerate temperatures of up to 200 °F (93 °C), which, combined with long sparge times, can mean more extraction. Oat and rice hulls contain none of the dreaded tannins, so combining wheat malt and oat or rice hulls enables you to raise the sparge temperatures with no adverse effects on the wort.
Enzyme levels: Once you get past the potential problems with the protein structure, glucans, and the stuck runoffs, wheat malt stacks up quite favorably to barley. The remaining question is whether the malt contains sufficient enzymes for conversion. Many modern wheat malts are well modified and do indeed appear to contain sufficient enzymes to support an all-wheat mash. What’s more, wheat malt is typically cheaper and is said to add about 4 points to your extract yield compared with barley malt.
Again, check the specifications for your malt of choice. Wheat requires more care during the malting process than does barley, and variations in malting methods can thus have a great effect on the resulting malt. Temperature control is critical; wheat germinates quickly, and high temperatures can kill off precious enzymes before they have a chance to do any work. Typical analyses provided from several maltsters suggest that European malts may be lower in enzymes than American wheat malts, probably because of their malting techniques or the varieties of wheat used. Those who wish to brew traditional German Weissbiers with German malt might need to make use of painstaking mash techniques such as decoction to maximize the performance of available enzymes.
If you’re really concerned about having enough enzymes for conversion, amylase enzymes can be added to the mash, though traditionalists might argue that such additives are certainly outside the bounds of Reinheitsgebot. (Of course, the use of oat or rice hulls may also be considered a breach of Reinheitsgebot, even though they are used as filtering agents only.)
To put this theory to the test I brewed four beers using wheat malt as the only source of fermentable sugar. I felt like experimenting, so I decided to brew traditional German Weizen styles — a Weizenbock and two versions of a pale Weizen — and a beer as close to a stout as I could come using all wheat. Though my own experiments involved some more advanced techniques and the use of additives to optimize my brews, brewers should not be deterred from attempting an all-wheat brew using simpler techniques, even single infusion. One maltster claimed success with all-wheat beers in pilot brews using a single-infusion mash — with no rice hulls (of course, the coarse grind they achieved may be out of reach of most home brewers).
Weizenbock: The first brew was a Weizenbock using pale, dark, and CaraWheat malts from Malteries Franco-Belges, which offers a great line-up of specialty wheat malts (see the box above for complete recipe details of this and the other three beers).
My first test was to see how the beer would come out without any additional enzymes. I chose a triple decoction mash schedule to maximize the beer’s body, color, and flavor. Many brewers debate the necessity of decoction, but there’s no question it is the technique of choice for German wheat beer brewers, and if it’s good enough for them, it’s good enough for me. After all, I wasn’t trying to see how little work I could do to produce an acceptable beer; I wanted to try to brew the best beer I could. Unfortunately, because I didn’t brew the same recipe several different ways, I don’t have any way of knowing which techniques contributed most to creating the resulting great beer. In addition to the triple decoction, I decided on a two-hour boil to get as many proteins as possible to drop out in the break.
In spite of the triple decoction with acid, protein, and beta and alpha rests, the mash yielded an extraction efficiency of only 61%,* much lower than the 73–75% efficiency I would normally expect with a conventional Weizenbock. The yeast also seemed to have a hard time, despite a strong (1½-L) starter of Wyeast #3056 Bavarian wheat yeast that was stepped up to the expected original gravity. Fermentation at 65° F (18 °C) was slow and protracted, never reaching high kräusen and taking three to four weeks to ferment from an original gravity of 1.066 to a final gravity of 1.022 (apparent attenuation was 67%).
The beer was worth the wait, however. The finished product is clear and light caramel in color with a tight, thick head. The flavor is smooth with subtle malt flavor and heavy mouthfeel and notes of bananas and apples in the nose. I would like to try brewing this one again with additional enzymes and a good yeast nutrient, though it’s possible that using a different base malt or an even larger yeast starter might help. I would expect that adding enzymes would boost the mash efficiency into the low 80s.
*Efficiency was calculated using Greg Noonan’s formula as shown in the 1997 Brewers’ Market Guide.
Porter Weizen: I was hoping to brew a wheat stout, but the specialty grain selection limited the complexity of the grain bill. So I settled for what I call a Porter Weizen, using pale, dark, roasted, and CaraWheat malts, all from Franco-Belges. I tried a full-blown step mash for this one, with added enzymes. The mash efficiency was 76%, compared with the 72% or so I usually get for porters. The original gravity was 1.054.
I pitched a fresh ale yeast kindly donated by the Wild Duck Brewery (Eugene, Oregon), which they describe as being somewhat Chico-esque in flavor, but stronger and more attenuative with good flocculation. The fermentation was brisk, taking four days to yield a final gravity of 1.013 and an apparent attenuation of 76%. The finished beer is something of a cross between a Dunkelweizen and a brown porter. Pouring with a thick, dark head, this dark chocolate-colored ale has the silkiness of Guinness stout without the dry roastiness. While it is not technically true to style as a porter, it is in my opinion a beer worth brewing and savoring with friends.
The pale Weizens: The last beers I brewed were simple pale Weizens. My first recipe used only Franco-Belges wheat malt, with added enzymes. I used a single decoction mash on this beer and pitched with the Weizenbock Bavarian wheat yeast. The beer was a rousing success, with an original gravity of 1.060, final gravity of 1.012, and a mash efficiency of 83% — much higher than the 73–75% I usually get with similar beers. The finished product is smooth with a classic wheat tang and a hint of clove and apples.
I wondered if I could brew the same beer without adding extra enzymes. I was aware that some domestic malts appeared to have more enzymes than the European malts, so I thought I’d try some Great Western wheat. I used the same quantity of malt and the same mash technique. Unfortunately, I was unable to use the same yeast, and had to pitch a fresh starter of Edme dry yeast. The second beer packed a bit less punch up front, with an original gravity of 1.055, but to my surprise the efficiency was a respectable 76%. Fermentation lasted six days, and the beer finished with a gravity of 1.020 — an apparent attenuation of just 63%, for some reason. The finished beer is smooth and subtle, an easy drinking beer. The Edme yeast gave the beer more of an American wheat beer flavor profile, with the wheat flavors dominating. Both beers poured clear with thick white heads that last to the bottom of the glass.
Though this experiment was never intended to be scientific, it’s clear that the use of a lautering aid such as oat or rice hulls can enable brewers to work with an all-wheat mash with less frustration. The increased availability of specialty wheat malts allows for more creativity in recipe formulation. The rest of the technique depends on the malt itself — the variety used, malting techniques, and ultimate degree of modification. I remain convinced that well-timed rests will result in more extract yield and a better beer and that decoction brings out more body and color, and I will probably add enzymes and yeast nutrients the next time I brew with 100% wheat. After all, they can’t hurt and may remove some of the variables from brewing an all- wheat beer.
Thanks to Jim Bresler at Briess for sharing his experiences brewing all-wheat beers and for technical information about wheat malt, to the folks at Grain Millers for technical assistance, and to Anders Johansen for taking on the challenge of brewing a commercial all-wheat beer.
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