Climate effects on malt quality:

Through the last few years, different barley producing regions have been experiencing unusual drought. The dry and hot summer of 2021 had a devastating effect on the worldwide barley crop [1,2,3]. To add insult to injury, the effect on barley yields and malt prices might in fact not even be the most significant impact for the brewer. Heat and drought will shift gelatinization temperatures to higher temperatures [4,5,6]. Recent results supports that barley gelatinization temperatures are mostly determined growth conditions and very little by genetics.

If starch gelatinization temperature is much higher than saccharification rest temperature, it will cause trouble to the brewer. This is because that, the last starch fraction will gelatinize very slow during the saccharification starch gelatinizing very late in the mashing process, cannot be hydrolyzed by β-amylase which is inactivated at the end of the mashing process. This will in most cases it will result in a lower wort attenuation, but in some very extreme cases this late gelatinization can even result in filtration issues because of large unhydrolyzed starch molecules. While most brewers have designed mashing recipes to be well above the 60-63C temperature often cited, gelatinization temperatures from heat and drought stress barley will have significantly higher gelatinization temperature. In this case, the wort quality would benefit by a higher saccharification temperature.

However, this theory is currently is tricky for the brewer to apply; The malt producers do not routinely supply this parameter in the malt specification, and very few breweries have resources to routinely run RVA analysis on all incoming malt. This unknown change in malt quality introduced by “random” barley origins can cause batches with “identical” specifications (variety, malting, supplier) to cause sudden and unexplainable drops in wort quality.

High gelatinization malt will result in:

• Late extract formation
• RDF compromised

SIBA for RDF consistency - no matter malt quality:

Specshell assisted a European brewery with inline SIBA measurements of their production while experiencing unexpected malt quality fluctuation. By monitoring the malt gelatinization over this period, the brewery had troubles with RDF fluctuations and low wort attenuation in some production weeks. SIBA found the gelatinization temperature of the malt used, extraordinary high at 66.5C - more than one degree higher than the recipe saccharification rest temperature. By adjusting saccharification temperatures, the RDF of the wort was increased by more than 2%, ensuring the brand attenuation consistency. With the subsequent batch of malt, the gelatinization temperature returned to an ideal 61C, SIBA notifying the brewer to lower the saccharification temperature slightly again to obtain optimal B-amylase stability.

These results show how much brewers can benefit from inline measurements, that will give the a prompt warning if malt quality undergo changes, and allow the to work with difficult crops. Despite involvement of advanced barley breeding programs and good supply chain control, malt quality is largely determined by random regional weather conditions. We envision that the future of mashing will not be based on a static recipe but rather a dynamic mashing scheme adjusting temperatures according to in-line and real time data provided automatically to the brewer.

[1] Simpsons Malt (November 1, 2021) (https://www.simpsonsmalt.co.uk/blog/2021-barley-harvest-price-rises-market-analysis-and-what-this-means-for-malt-in-2022/) [2] Brewers Association (November 1, 2021) (https://www.brewersassociation.org/collab-hour/from-barley-to-beer-managing-malt-quality-in-a-changing-climate/) [3] Bryce, J. (Host) (October 25, 2021) Episode 228: The Challenging 2021 Barley Outlook (https://podcasts.apple.com/se/podcast/episode-228-the-challenging-2021-barley-outlook/id1156748005?i=1000539588772) [4] Ao Z.; Jane J. L., (2007). Carbohydr Polym; 67: 46-55 [5] Myllarinen P.; Schulman A A; Salovaara H; Poutanen K (1998) Acta Agricultural Scandinavia; Section B; Soil Plant Sci; 48: 85-90 [6] Tester R.F.; South J. B.; Morrison W.R., Ellis R.P. (1991). J Cereal Sci, 13: 113-127 [7] van Grunsven C.; Kunov-Kruse A.; J Grønborg; Lekuona