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BEST information on processing barley malt crop 2010

There have been sporadic reports in recent weeks of difficulties in processing barley malt crop 2010. On the one hand these involve the degree of cloudiness of worts and beers, and on the other hand difficulties during clarification and saccharification of the worts concerned.

For this reason we have compiled the following information:

1. Weather conditions in Germany during vegetation
Sowing was relatively late due to weather conditions, and in some regions was only completed by mid-April. Unusually cool temperatures in May and the beginning of June led to delays in growth; the weather then changed suddenly during the extremely hot spell from 18th to 24th June. This meant that in some cases the barley moved on to so-called premature ripening without an adequate grain filling period and without adequate precipitation. Premature ripening denotes early ripening due to adverse circumstances (which in this year constituted drought stress). The grain ripens abruptly when further starches would normally be assimilated and other important metabolic processes would take place in the barley grain. Whereas prompt and dry harvesting of the barley took place in early areas, the onset of rain which was abundant in places meant that harvesting in the middle and late areas was only possible from the middle to end of August. The consequences of the rainfall on barley that was ready for harvesting were frequently outgrowth and mildew which reduced the marketable goods available.

2. Possible consequences
Premature ripening meant that the barley formed small starch grains and, with insufficient ripening time, was unable to synthesise sufficient β-amylases or their precursor. The small starch grains are harder to break open in the malting and brewing process, i.e. to remove the usable extract, because the necessary β-amylases are also lacking in the malt or are not present in sufficient quantities.

A further consequence of harvesting circumstances is that the gelatinisation temperatures in the mash increase. The temperatures required to gelatinise the starch in the mash and thereby permit ideal enzymatic removal increase beyond the temperatures at which the β amylase rest usually takes place (62-63° C, 144-145° F). The standard malt analsysis, which is principally based on a congress mashing procedure that lacks practical relevance, unfortunately provides little information about this phenomenon. The only indications that can be derived with reservations from the malt analysis are merely opaque or slightly cloudy processes and somewhat lower extract levels.

In the frequently used high-short mashing schedule with a β-amylase rest at 62-63° C (144-145° F) the starch parts become too low and are only broken down incompletely. Whilst the subsequent α-amylase rest at 72-73° C (162-163° F) is above the gelatinisation temperature, it is often not of sufficient duration to prevent high iodine levels and low brewhouse yields. The saccharification time increases and unsweetened starch residues lead to cloudiness and thus to delays in clarification (so-called α-glucan cloudiness). Increased quantities of residual extract are found in the brewer grains (loss for the brewery). The worts are no longer bright when they run off but can even form cloudiness after the whirlpool. The final attenuation is also reduced for this reason.

The coming months will show whether the weather conditions described above had any other effects on the barley, and if so what these are.

3. Approach to resolve the problem
Since there are no possibilities for preventing or reducing these commodity-related influences using malting technology, possible problems can be countered during brewing by adapting the decoction programme. Often it helps to increase the temperature of the β-amylase rest above the gelatinisation temperature and where necessary extending the time for this rest. Gelatinisation temperatures of up to 65° C and above have been discovered in the current vintage. An alternatived approach can also be to extend the α-amylase rest.

No difficulties are to be anticipated when using traditional decoction mashing procedures.

All changes made to the brewing process must of course take all other circumstances into consideration, and the information here can merely serve as points of reference.

Barley harvested anywhere in Europe in 2010 may produce the undesired reactions presented here with respect to the malts produced from it. We hope that the information we have provided here will help the 2010/2011 brewing year to run smoothly and in the best case scenario for potential difficulties not to arise at all.

Please do not hesitate to contact us if you have any further questions.

BESTMALZ – for the best beers

written by BESTMALZ AG / Thomas Schumacher on 15.02.2011 um 10:57.

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