BrewingTechniques

Belgian Malts: Some Practical Observations

by George J. Fix

Republished from BrewingTechniques' May/June 1993.

Belgian malts offer qualities and performance profiles that differ markedly from their North American and British counterparts. This reporty on the results from experimental test brews based on Belgian malts reveals their strengths and limitations and provides recommendations for their use.

Belgium and France contain selected areas prized for growing top-flight malting barley. The ancestors of the modern varieties grown there can be traced back to the Middle East, where barley was first cultivated and malted (albeit using a primitive process). The evolution of ancient to modern strains of this malting barley is similar to the evolution of Vinefera wine grapes grown in France. Both have been selectively cultivated over the centuries for the desirable flavors they impart to their host drink.

The existence of Belgian malts was noted two years ago in a book I coauthored on Vienna-style beer (1). At that time, these malts were unavailable in North America. Rumors, however, held that this situation would soon change, and we alerted readers that popular availability of Belgian malts could alter our recommendations for the best type of malt to use in Viennas (1). These malts have now been in widespread amateur and commercial use for over a year. The results have been highly favorable, influencing virtually all of the major beer styles, of which Vienna-style beers are but one example. (See the section on "Roasted Malts" for further discussion of the Vienna style.) Belgian malts have shown different characteristics from those of standard malts in terms of clarity of run-offs, color, yield, and other factors. This article discusses the implications of Belgian malt characteristics.

The Belgian grains that are available today are all malted at DeWolf-Cosyns in Brussels, Belgium. DeWolf-Cosyns is one of the oldest and most prestigious companies in Europe and is known for having uncompromising standards of malt quality. Although a relatively large company, DeWolf-Cosyns nevertheless continues to use the traditional floor malting process. Floor malting is very expensive, but it produces the best malt (2). Another positive aspect of DeWolf-Cosyns is the diversity of the malt types they produce. The company has long supplied Belgium's many specialty brewers with a variety of specialty malts. All of these malts are being imported and are currently available to North American brewers.

Yield -- the percentage of a malt's weight that is convertible to extract -- is an important consideration when evaluating malts. Most home brewers and some pub brewers work with gravity points instead of extract. These brewers typically define yield as the number of gravity points that are obtained for a given malt rate; this measure of yield is expressed in terms of points/pounds/gallon. The present study uses a standard percentage value for yields. The Plato tables enable us to relate these two measures. If a malt yields Y% of extract, then 1 lb/gal of this malt will yield Y/100 lb/gal of extract, or 31Y/100 lb/bbl of extract (1 bbl = 31 gal). The Plato tables show that wort containing 1 lb/gal or 31 lb/bbl of extract has a specific gravity of 1.046. The general equation for translating points to percent yield is therefore

points/lb/gal = 0.46Y

Thus, a 60% yield is equivalent to 28 pts/lb/gal, and a 70% yield is equivalent to 32 pts/lb/gal.

This article reports the results of various test brews. To standardize the reported results, the same wort production procedure was used for each (see box). When using North American pale two-row malts like Klages and Harrington, the standardized procedure typically produces yields of 62-64%, real degrees of fermentation of 63-65%, and apparent degrees of fermentation of 77-79%. The values obtained for the Belgian malts are presented below.

Standardized Wort Production Procedure

Total volume of water:
64 L of distilled water, into which 30g of calcium chloride was dissolved
Volume of mash water:
32 L
Volume of sparge water:
32 L
Mash cycle:
30 min at 52 degrees C, 30-min transition to 68 degrees C, 45 min at 68 degrees C, 5-min transition to 71 degrees C, 10 min at 71 degrees C
Volume of collected wort:
56 L
Boil time:
1.5-2 h
Volume of finished wort:
50 L

PILS MALT

In Europe, Pils malt generally refers to malt made from top-quality, low-protein, two-row barley. It generally has modest diastatic powers, is quite pale in color, and is much less modified than ale malts. European lager brewers tend to prefer undermodified malt, partly because of tradition and partly because of the superior storage properties these malts are reported to have.
Table I shows the data on the DeWolf-Cosyns' Pils malt.

The kernels are plump and uniform in size; there are virtually no small kernels. In fact, this is true of all of the malt discussed in this article, indicating uniform germination typical of floor malting systems. The Pils malt has much harder kernels than ale malts, which indicates that the latter are more modified. The degree of modification is evident when the malts are chewed or milled.

DeClerck found that the best protein levels for malted barley were in the 9-11% range (2). The DeWolf-Cosyns Pils malt falls in the middle of this range, which is ideal. It is important to note that few North American malts fall in the DeClerck range. Most two-row malt is 11.5-12.5% protein, and six-row malts are typically >12.5% protein. One feature of low-protein malts is their relatively low diastatic power, the measure of the grain's enzymatic strength; the higher the diastatic power, the stronger the malt's enzyme system. North American two-row malts typically have diastatic powers in the 125-135 degrees Lintner range, and six-row malts are stronger still. The Belgian Pils malt is roughly 25% below that. The enzyme system in the Belgian Pils malt is therefore not strong enough to convert the starch in a mash that contains a high fraction of adjuncts (here adjunct refers to any grain that has little or no enzymes, such as roasted malts and unmalted cereal grains). With a diastatic power slightly above 100 degrees Lintner, the Belgian Pils malt is capable of converting its own starch and perhaps a 15-20% adjunct level in the grain bill. Brewers should be cautious about using higher adjunct levels.

Low-protein malts also typically produce high yields, and the difference between fine- and coarse-grind yields is small. This is certainly true of the Belgian Pils malt. It should be noted that the numerical values for the yields cited in Table I were obtained under laboratory conditions. It is generally not possible -- or desirable -- to achieve these yields in practical brewing situations. The accompanying box (Test Brew #1) shows typical results achieved using my 50-L system.

Test Brew #1 -- Pils Malt

Grain bill:
10 kg of Pils malt
Original extract:
13.1 P (1.053)
Yield:
68.4%
Mash pH:
5.3
Fermentation:
Lager yeast W-206, 10 days at 10 degrees C,
2-day cooling to 4 degrees C
Real extract:
4.5 P (1.018)
Real degree of fermentation:
65%
Apparent extract:
2.6 P (1.011)
Apparent degree of fermentation:
80%

I found that decoction mashing produced a slightly higher yield and a slightly deeper color. Other than that, the differences between infusion and decoction mashes with this malt were not great.

S-methyl-methionine (SMM), the major dimethyl sulfide precursor in malt, usually provides a good indicator of the intensity of a beer's malty/sulfury taste (3). SMM levels, however, provide no clear indication of the character of these flavors (4). For example, malt from Midwestern North American six-row barley and German Pils malt typically both have SMM levels in the range of 8-10 micrograms/gram of malt, yet beer flavors from these malts differ dramatically. At the other extreme, top-quality pale ale malt from the UK typically has SMM levels in the 1-2 micrograms/gram range. These malts have been produced for ales in which sulfuric flavors of any kind -- good or bad -- are unwelcome. The Belgian Pils malt falls in the middle of these two extremes. It will impart some malty/sulfury flavors -- lager beer tends to be insipid without such flavor components -- but the effect is not as intense as when using German Pils malt. For lager brewers, SMM levels may be the key determiner when deciding which Pils malt to use. Many brewers may find the moderate SMM levels of the Belgian Pils malt to be a defect.

Another concern about Belgian Pils malt is its moisture content. Commercial criteria typically call for moisture levels to be <4% (2). Brewers using Belgian Pils malt should periodically check to make sure that the grain has not deteriorated. Grain deteriorization will reduce yields and introduce musty tones to the finished beer. It is also advisable to store these malts in a cool, low-humidity area to prevent further water uptake.

PALE ALE MALT

Ale brewers -- whether in the UK, Belgium, or North America -- have traditionally been fussy about the malt they use. The DeWolf-Cosyns pale ale malt was clearly produced with this fussiness in mind. It is a low-nitrogen (low-protein) malt, is well modified, and has minimal SMM levels. The high degree of modification is evident by chewing some kernels. They are almost as soft as marshmallows. Specific data are shown in Table I.

This malt's low diastatic power places definite limits on the amount of adjuncts that can be included with it in the grain bill (possibly no more than 10-15%). Notice that this malt has almost twice the coloring potential of the Pils malt; very little roasted malt is needed to give the finished beer a deep amber hue, if that is desired. The mashing schedule cited in the introduction was used in the pale ale test brew (see box, Test Brew #2). Given this malt's high degree of modification, the rest at 52 degrees C was likely redundant. Otherwise, its brewhouse performance was quite similar to that of the Pils malt.

Test Brew #2 -- Pale Ale Malt

Grain bill:
10 kg pale ale malt
Original extract:
13.3 P (1.054)
Yield:
68.8%
Mash pH:
5.2
Fermentation:
Ale yeast (Siebel/Crosby & Baker BRY-96), 5 days at 20 degrees C,
2-day cooling to 5 degrees C
Real extract:
4.5 P (1.018)
Real degree of fermentation:
66%
Apparent extract:
2.5 P (1.010)
Apparent degree of fermentation:
80%

The pale ale malt has a classic English character; it imparts a definite "maltiness" to the finished beer, yet sulfury effects are totally absent. Many people use ester levels as a discriminator between ales and lagers. I believe that this method is not strictly valid because certain lagers do well with a high ester profile, and conversely some ales do well with a subdued ester profile. A far better discriminator is the malt character of the finished beer. Lagers tend to be insipid without some hints of that Central European malty/sulfury flavor tone. On the other hand, I cannot think of a single ale style in which such flavors would be welcome. Ale brewers who agree with these observations will view the very low SMM levels of the DeWolf-Cosyns pale ale as advantageous.

A natural question to ask is how Belgian pale ale malt stacks up to the top English two-row malt, namely Maris Otter (Great Ryburgh, England). What follows may sound like a cop out, and it likely is, but I feel it is too close to call. Both are outstanding. In fact, malt data on each are remarkably similar, and actual brews indicate that their color and flavor contributions are similar as well. The best advice I can give is to let price and availability determine which malt you choose. Brewers will not regret a decision for either malt.

The same comments about moisture levels made for the Pils malt apply to the pale ale malt as well.

WHEAT MALT

My interest in wheat beers goes back nearly a decade (5). At the time that I wrote Wheat Beers, no commercial wheat beers were brewed in North America, despite their popularity in Central Europe. Since that time, interest in wheat beers among both amateur and commercial brewers has grown tremendously in North America. The popularity of wheat beers for pub brewers has lead to what many regard as a new beer style, namely "wheat ales." One reason for the success of wheat beers is that selected varieties of domestic wheat have done well in both malting and brewing. In addition, excellent wheat malt has been imported from both the UK and Germany. To these riches can now be added a version from Belgium. The data on the Belgian wheat malt is shown in Table I.

The values for wheat malt extract on an "as is" basis ("wet" measured, in wort) are unavailable. The numbers reported for the dry basis will always be slightly higher. The extract values reported for the other malts in this article were all measured on an "as is" basis.

In his recent excellent book on wheat beers, Eric Warner cited the following criteria for wheat malt (6):

      Extract (dry basis): >83%
      Protein (dry basis): <12.5%
      Fine-to-coarse grind
      difference: <2.0%

The Belgian wheat malt satisfies the first two but not the third. The fine-to-coarse grind difference is 2.5%, which slightly misses the mark. (All of the other Belgian base malts, however, were less than 2%.) This value is a traditional figure that, along with protein levels and other parameters, has been used as a measure of malt quality. The moisture level of this malt would also be regarded as unacceptable by most commercial brewers. This malt should definitely be checked during storage.

I am unable to report on the practical significance of these deficiencies. I have yet to use the malt in full-size 50-L brews. Pilot 5-L brews indicate that it performs perfectly fine. In this regard, the procedures and recipes in Warner's book can be highly recommended for this wheat malt.

COLOR MALTS

Color malts are kilned at a higher temperature than base malts but are not roasted. The two color malts offered by DeWolf-Cosyns are excellent examples. Both have sufficient enzymes to convert their own starch, a fact I confirmed with 5-L pilot brews using the standardized mashing schedule described in the introduction. I tested the Munich and aromatic malts, each on a stand-alone basis. Both gave a negative iodine reaction after 45 min at 68 degrees C. Thus, both can be included in a grain bill at any level that is desired. These malts come not only with a strong color potential, but also with very special flavor and aroma profiles. I highly recommend Darryl Richman's article on page 34 of this magazine for further discussion of the use of Munich malts (7).

The critical data for Munich and aromatic malts are shown in Table I. The carbohydrate structure of these malts indicates a high fraction of 1-6 links (3). These links will not be broken by amylase enzymes in a normal mash. Consequently, these malts will always make significant contributions to the dextrin pool even if they are fully mashed. The Munich malt could be used on its own, and pilot brews indicate that a real degree of fermentation in the range of 45-55% will be achieved. Beers with elevated dextrin levels like this were common in traditional Munich brewing (7).

Aromatic malt, on the other hand, should be thought of as an adjunct malt to be used only in small amounts because of its high color and flavor potentials and its very high fine-to-coarse grind differences.

Moisture levels of highly kilned malts are typically half that of pale malts (2). This is not the case for these color malts -- a problem that seems to be present with all of the Belgian malts. Again, it is important to store these malts in a cool, dry environment and to check them periodically for deterioration.

ROASTED MALTS

None of the roasted malts have enzymes. Therefore, their starch will have to be converted by enzymes from the other malts used. In my opinion, these malts are the gems of the Belgian collection. There are reasonable substitutes for the other malts discussed in this article, but these malts have no equal. I discuss them in three separate groups. Their profile data are shown in Table II.

The first group comprises Caramel Pils, Cara-Vienne, Cara-Munich, and Special B malts. The Cara-Vienne malt has the most attractive caramel-sweet aroma that I have ever encountered in a malt. It leaves an extremely pleasant tone in the finished beer. The accompanying box shows the results of a test brew based on our currently preferred version of the standard Vienna style. This version is not as malty as those based on German malts, but its finish is a good deal more elegant.

Test Brew #3 --Cara-Vienne Malt

Grain bill:
9 kg Belgian Pils malt, 1 kg Cara-Vienne, 0.5 kg Special B
Original extract: 13.5 P (1.055)
Yield: 67.8%
Mash pH: 5.2
Fermentation:
Lager yeast W-34/70, 9 days at 10 deg. C, 2-day cooling to 4 deg. C
Real extract: 5.0 P (1.020)
Real degree of fermentation: 63%
Apparent extract: 3.0 P (1.012)
Apparent degree of fermentation: 77.8%
Beer color: 9 degrees L

What the Judges* Say about
Cara-Vienne-Based Oktoberfest (Test Brew #3)
Bouquet/Aroma: Good malt aroma; very slight diacetyl bouquet and aroma, true to style
Appearance: Excellent deep amber color; good clarity; good head retention; lace is good
Flavor: Very malty, appropriate for style; good balance for style; good carbonation; alcohol level appropriately high
Body: Medium
Overall Impression: Wonderful beer; I can't find a flaw; gimme more!

*New England Competition, Westport, Massachusetts, 27 February 1993; event sanctioned by the Home Wine & Beer Trade Association and American Homebrewers Association.

The next malts -- chocolate malt, roasted barley, and roasted malt -- are the heavily roasted black malts. Chocolate malt is distinguished from the others because it has been debittered; thus, it will not impart that burnt coffee taste that highly roasted malts sometimes do. That taste, of course, can be either desirable or undesirable, depending on the beer style.

The last of the roasted malts to be discussed is the Biscuit malt. Simply chewing some kernels will give you a clear indication why this malt is so named. I haven't the slightest idea how this malt might be used in a recipe, other than the intuitive feeling that someone might create an entirely new beer style with it. It is interesting to note that DeClerck often used the descriptor "biscuit flavored" to characterize roasted malts (2). This malt makes such characterizations fully explicit.

WORT CLARITY

Most European malts have much higher lipid levels than North American malts, and the Belgian malts have some of the highest lipid levels in Europe. High lipid levels will be readily apparent to the brewer by the type of run-offs observed during the sparge. Run-offs from Belgian malts will be considerably more turbid than would those of North American malts, and they require far more recirculation to achieve full wort clarity.

This raises the issue, widely discussed by writers in both the amateur and commercial literatures, of how important it is to achieve completely clear run-off into the kettle (3). Although such a large issue cannot be resolved in an article such as this, I noted the following features in my experience brewing with Belgian malts:

  • Finished beer clarity will not be adversely affected by turbid run-offs. In fact, if a flocculent yeast strain is used, the beer will fall brilliantly clear after only a brief postfermentation storage.
  • Beers that have been made with fully clarified worts show a greater stability in terms of chill haze and a longer shelf life in terms of staling. Brewers of mildly flavored beers report a stronger preference for beers made from clarified worts, while brewers of bigger beers report the reverse.
  • The lipid carryover to the fermentor has beneficial effects on yeast metabolism.

    Commercial brewers of bottled beer, whose products are expected to have a shelf life of 4-6 months under market conditions, may be reluctant to use these malts because of their high lipid content. Others may come to different conclusions.

  • REFERENCES

    (1) G.J. Fix and L.A. Fix, Vienna (Brewers Publications, Boulder, Colorado, 1991).

    (2) J. DeClerck, A Textbook of Brewing, Vol. 1 (Chapman and Hall, London, 1957).

    (3) G.J. Fix, Principles of Brewing Science (Brewers Publications, Boulder, Colorado, 1989).

    (4) G.J. Fix, "Sulfur Flavors in Beer," Zymurgy 15 (2) (1992).

    (5) G.J. Fix, "Wheat Beers," Amateur Brewer 11 (1984).

    (6) Eric Warner, German Wheat Beer (Brewers Publications, Boulder, Colorado, 1992).

    (7) Darryl Richman, "Thinking about Beer Recipe Formulation," BrewingTechniques 1 (1), 34-35 (1993).

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