What is the quality requirement of Malting barley?

Barley is one of the oldest grown grains cereals. Around 150 million tonnes of barley are produced per year. Main region of production is Europe (Germany, France, Denmark), Russia, Ukraine, Australia, Canada, and Argentina (figure 1)

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Figure 1: barley product per country (USDA)

Barley is an important food source for humans and animals and a key ingredient in some alcoholic beverages (figure 2). Around 30% of barley is use for malting from which 90% is for beer production.

Figure 2: Barley application

The quality requirement of malting barley can be classified in four categories (table 1):

Food Safety
Physical Grain Quality
Technological & Organoleptically
Sustainability & Operational Efficiency

Food safety: in relation to mycotoxin, chemical and heavy metal residues.

Mycotoxins could occur during the barley growing period or during the barley storage. The main mycotoxin detected on malting barley are the Deoxynivalenol (DON), Ochratoxin (OTA) and T2HT2. Barley plant protection, origin selection, sanitation of the installation, temperature and moisture CONTROL are the main element to limit the risk of mycotoxin.
Regarding pesticides, the main tests are focussing on plant growth regulator, herbicide, and storage insecticides. Main key production country has a positive list of plant protection allowed on malting barley. Furthermore, an MRL (Maximum Residue Level) is define for each product by each country.
In addition, sanitation, moisture, and temperature are keys element to monitor to ensure a good barley storage and avoid mycotoxin & insect development & to preserve the germination capacity.

The physical grain quality are criteria of selection between feed and malting barley. The main parameters are:

Germination is one of the most important parameters as barley cannot be processed to malt with poor germinated barley. In general, the malting industry requires a minimum of 95% germination after 5 days.
The protein level plays a key role in the malt, beer, and whisky production. Indeed, some proteins are responsible of the beer foam stability. However, an elevated level of protein could generate beer turbidity. In addition, more protein led to have less starch meaning less alcohols produce in fermentation. The protein level is one of the big differences between the brewing and the distilling industry. Brewer is requiring a protein level between 9.5-11.5% whereas the distilling is requesting low protein level. At the opposite of feed segment will prefer high protein content.
The calibration, the fraction higher than 2.5mm and below 2.2mm are key. In general, the specification is minimum 90% over 2.5mm and maximum 2% below 2.2mm for the malting industries. Those limits ensure a certain homogeneity of the grain that would also mean a homogeneity of water uptake during the steeping process.
The hectolitre weights have a key role to play for storage capacity, transportation and have influence on the malting plant production capacity.
The moisture level needs to be lower than 14.5% to ensure good storage and avoid mycotoxin, insect and to preserve germination capacity.

Technological & Organoleptically aspects are typical evaluated in the different national evaluation program like the Berliner program process, CBMO, MBC, Danish Preferred. Barley is the soul of beer like grape from wine, indeed some key flavour components depend on the growing region and / or the variety genetic property. That is why many parameters are used to evaluate the technical characteristic of a variety, which can be summarise as such:

Physical modification is corresponding to the physical degradation of the grain by the different enzyme develop during the malting process. Friability, viscosity, and the Beta-Glucan level are the main important.
Proteolytical modification is corresponding to the level of degradation of the barley protein into smaller unit like free amino nitrogen. Key parameters are soluble proteins, free amino-nitrogen and Kolbach index (ratio between soluble protein and total protein)
Amylolytic modification describe the production during the malting process of the enzyme that will degrade the starch into fermentable sugar during the brewing process. Main amylolytic enzyme are the Alfa and the Beta amylase.
Technical aspect like extract, the wort & beer filterability, flavour, turbidity is also tested.

Operation efficiency & sustainability are criteria increasingly important to answer to society preoccupation and to respect some international agreement like the Paris agreement. Variety has multiple impact on disease resistance, the nitrogen resilience and the processability (malting & brewing). In addition of the obvious parameters like agronomical yield, more elements like untreated yield, processed yield and processed moisture have been introduced to better characterise varieties. SAATEN-UNION develop a model to asset variety on sustainability ( SAATEN-UNION: The supply chain should become more sustainable. – YouTube)

When it came to the distilling segment, the main quality criteria described above apply also. One of the big differences is that foam is not important in whisky. In that regard, the distilling is looking to the maximum quantity of starch and extract to maximizing the alcohol production. The industry uses the PSY measurement to predict the yield in alcohol. Another critical parameter in distilling is the absent of glycosidic nitril. Indeed, the glycosidic Nitril (GN) is the precursor of a cancer molecule. That is why non GN variety are in general require for distilling.

In the bakery application the amylase activity and the flavour are the most important criteria.

Table 1: Main quality parameters per barley application

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Food safety

DON

MRL

DON

OTA

T2HT2

MRL

DON

OTA

T2HT2

MRL

DON

OTA

T2HT2

MRL

Physical grain quality

TP>11.5%

HW

Starch

Variety

TP 9.5-11.5%

>2.5mm >90%

HW

Germination

Variety

TP <10.3%

>2.5mm >90%

Germination

HW

Variety

TP>11.5%

>2.5mm >90%

Germination

HW

Technological & organoleptically

Cellulose

Fibre

Beta-Glucan

Free Amino Nitrogen

Extract

Predicted Spirit Yield

No Glycoside Nitril

Hot Water Extract

Amylase Activity

Vitamin

Ferulic acid

Beta-Glucan

Sustainability &Operational efficiency

Yield

HW

Disease resistance

Adaptability to grow close to the need

Yield

HW

Disease resistance

Water in process

Processability

Adaptability to grow close to the need

Yield

HW

Disease resistance

Water in process

Processability

Adaptability to grow close to the need

Yield

HW

Disease resistance

Adaptability to grow close to the need

Farming Impact on barley quality

As illustrate the figure 3, every farming step impacts the final product quality.

That starts by the selection of the barley variety adapted to the environmental condition and the final usage objective. Thorough equipment cleaning will guarantee homogeneous barley..

The sowing density will also have an impact on the calibration. Indeed, sowing density needs to be adapted to the soil, climatic condition, and the period to ensure an optimal grain per square meter.

The herbicide regime needs to be of high quality to ensure a minimum of unwanted seeds are present after harvest.Also, a robust fungicide programme is required to minimise the presence of mycotoxins.

Good quality, timely harvesting is also required to ensure low grain damage and skinning, this also ensures the correct moisture content. [Une image contenant texte, capture d’écran, intérieur, très coloré Description générée automatiquement]

Figure 3: Farming step & quality impact

Barley application segment has developed its own set of requirements to answer to food safety, sustainable and organoleptic constrain. Each criterion of selection has a direct impact on the processability and / or the quality of the final product. Farming practices have a significant impact of the final quality. Breeders are continuously working to develop new variety to improve the performance of the barley to beer supply chain.

Over the year SAATEN-UNION develop some hight performer variety like MARTHE, Grace, ACCORDINE, FANDAGA, AMIDALA, FIREFOXX and Sting.