Malting barley varieties: Metcalf

Bill Ladish
Cargill Malt, Specialty Products Group

The Canadian 2-row malting barley variety CDC Harrington has long been the standard bearer of international commerce. Its smooth and neutral flavor profile, combined with enzyme levels significantly higher than traditional European varieties of the same level of total protein, makes it well suited for the production of lager beers. Harrington was developed by Dr. Bryan Harvey at the Crop Development Centre at the University of Saskatchewan in Saskatoon. Hence the initials CDC. Dr. Harvey just retired as the dean of Canadian malting barley breeders, with the development of Harrington being his proudest accomplishment.

However, Harrington was registered in Canada in 1981. So it has been on the scene for more than twenty years. During that extensive time period the development of new barley lines, and more importantly the development of lines with improved agronomics in those crops which compete for acreage with malting barley in Canada, has proceeded unabated. By the late 1990s it was apparent that Harrington was losing acreage. Harrington reached its highest percentage of the total area seeded to barley in Canada in 1993 at about 38%. That figure dropped to about 21% in the year 2000, and to about 8% in the 2004 crop year. The trend is anticipated to continue with the 2005 crop.

To their great credit, the Canadians released three new varieties in the late 1990s as potential replacements for Harrington. This would enable the market to determine which varieties would succeed and which would fail. AC Metcalfe was registered in 1994. The initials AC stand for Agriculture Canada. Metcalfe was developed by W. G. Legge at the Agriculture Canada Experimental Station at Brandon, Manitoba. The varieties CDC Kendall and CDC Stratus were registered in 1995. More recently the variety CDC Copeland was registered.

As anticipated, the market is rendering its judgment. In the 2004 crop year 56% of the barley acreage planted was seeded to 2-row malting varieties. About 36% was seeded to feed varieties, and 8% was seeded to 6-row malting varieties. The acreage seeded to 6-row malting barley varieties in Canada has been dropping precipitously in recent years. The 56% of acres seeded to 2-row in Canada in 2004 break down as follows, in descending order.

Metcalfe 47.4%
Harrington 14.9%
Kendall 14.3%
Copeland 8.6%
Merit 4.6%
Stratus 4.5%
Stein 2.9%
Others 2.8%

Clearly Metcalfe is the apparent winner, with almost half the acres seeded to 2-row malting varieties. In 2005 this trend is expected to continue. Also in 2005 Kendall is likely to pass up Harrington, and Copeland will come on strong. Stratus appears to be falling by the wayside. Only limited domestic demand is anticipated in 2005 for both Stratus and the Busch Agricultural Resources variety Merit.

In what follows we will focus our comments on Metcalfe. Subsequent articles will discuss primarily Kendall and Copeland.

Metcalfe is a cross of the previously well-known Canadian varieties of Oxbow and Manley. For those interested, Harrington has Klages in its parentage. The parentage of Harrington is Klages/(Gazelle/Betzes/Centennial).

One of the hallmarks of Metcalfe is its improved agronomic performance relative to Harrington. Those familiar with Harrington know that it has a tendency to have loose hulls. All four potential replacement varieties have improved hull adherence relative to Harrington. Overall agronomic yield for Metcalfe is about 8.5% higher than Harrington. Similar values for the other varieties are 7.5% for Kendall and 10% for Stratus. Metcalfe has improved scores relative to Harrington on lodging resistance, net blotch resistance, stem rust resistance, and resistance to smuts, particularly to loose smut.

Comparisons of malt analytical data across varieties has to be done with great care. Typically maltsters have to work with a variety for a while to optimize processing conditions. When that is completed, different varieties tend to be selected for different customers and processed differently. So, while great amounts of data are available, there is only limited data available when all varieties are processed under generic conditions in an attempt to quantify differences across varieties. The writer is aware of only two such studies. One was done internally at Prairie Malt Ltd (PML) and brewing at the Great Western brewpub in Saskatoon using 1999 crop barley. The other is an extensive study done by our former colleague Dr. Yueshu Li and his colleague Aleksandar Egi at the Canadian Malting Barley Technical Centre in Winnipeg. They used barley from the 1999, 2000, and 2001 crops and included Copeland. This latter study has been published. Li & Egi: “New Canadian Malting Barley Varieties and Their Malting and Brewing Characteristics,” Master Brewers Technical Quarterly, volume 41, number 2, (2004) pages 104-100.

Here is the original comparative data, generated at PML. Represents at least 30 batches each. Generic processing.

Metcalfe Kendall Harrington
Friability, % 86.5 90.7 85.7
Moisture, % 3.9 3.9 3.9
Extract, Fine, dry, % 81.7 82.4 80.6
F-C Extract, dry, % 0.8 1.0 1.4
Wort Color, Lovibond 2.00 1.95 2.10
Wort Viscosity, cP 1.48 1.47 1.49
Total Protein, dry, % 11.2 11.0 11.3
Soluble Protein, dry, % 5.0 4.8 4.7
S/T (Kolbach Index), % 44.7 43.8 41.3
Free Amino Nitrogen, mg/L 175 159 158
Diastatic Power, Lintner 151 161 128
Alpha Amylase, DU 54.9 53.0 49.2
Beta Glucan, mg/L 88 81 88

Both Kendall and Metcalfe are capable of producing malt at the same level of total protein and moisture, with adequate modification, as Harrington. Metcalfe appears to have the more potent enzyme package. Diastatic Power and a-amylase are higher than Harrington. Metcalfe also has a higher rate of proteolysis. Note the higher soluble protein and S/T values. Yet wort color is not materially higher than Harrington. Friability and fine-coarse extract difference are improved relative to Harrington.

One surprising aspect of this data set is the similar values for b-glucan across varieties. This is not typical of the variety. As the year progressed it became apparent that Metcalfe produces noticeably lower levels of b-glucan than either Harrington or Kendall. This data relationship was also confirmed by Li & Egi.

This same data set also produced an average b-glucan for Stratus of 150 mg/L, significantly higher than that of Harrington. This may account for at least part of the reason why Stratus has not been as commercially successful as either Metcalfe or Kendall.

This low concentration of b-glucan in Metcalfe was also confirmed by processing data from the brewpub brewhouse. Metcalfe had a noticeably shorter run-off time than any variety tested. From the point of view of a maltster or brewer, this excellent performance in the brewhouse is the hallmark of Metcalfe, and is almost certainly responsible for at least some of its success.

We also found the following relationships of brewing data for Metcalfe relative to Harrington.

- Approximately equal ratio of fermentable sugars in wort.
- Similar rate of maltose utilization during fermentation.
- Similar rate of Plato decline during fermentation.
- Slightly higher alcohol production during fermentation.
- Similar pH during fermentation.
- Slightly lower VDK production during fermentation.
- Slightly less FAN utilization during fermentation.

At Cargill Malt, Specialty Products Group, we are attracted to the lower b-glucan and run-off times of Metcalfe, the higher extract of Kendall, and the growing popularity of both varieties with Canadian growers. Thus we construct our Cargill Two-Row Pale base malt as a blend of both varieties. The barley is selected at PML and malted either there or at Jefferson Junction, WI.