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Created page with "For a general overview of grain in brewing, see [http://www.homebrewtalk.com/wiki/index.php/Grain Homebrew Talk Wiki page on Grain]. ==Microbial Populations on Barley== ===Ma..."
For a general overview of grain in brewing, see [http://www.homebrewtalk.com/wiki/index.php/Grain Homebrew Talk Wiki page on Grain].
==Microbial Populations on Barley==
===Malting Process==
Microbial communities found on barley are very diverse and change significantly throughout the malting process, with more diversity occurring further along in the malting process. In the barley fields, Gram-negative bacteria (especially ''Erwinia herbicola'') are abundant. Climate is said to have the most impact on which species grow in barley fields. For example ''Fusarium'' species are encouraged by high humidity, and are associated with mycotoxins and gushing problems in beer. During dry storage of barley, spore forming bacteria tend to survive. Xerophilic fungi (fungi that doesn't need much water) also survive on dry barley during storage <ref name="Lievens1">[https://lirias.kuleuven.be/bitstream/123456789/323403/2/Just%C3%A9%20et%20al.%202011_Microflora%20during%20Malting%20of%20Barley%20Overview%20and%20Impact%20on%20Malt%20Quality.%20Brewing%20Science%2064,%2022-31..pdf Microfl ora during Malting of Barley: Overview and Impact on Malt Quality. A. Justé, S. Malfl iet, M. Lenaerts, L. de Cooman, G. Aerts, K. A. Willems and B. Lievens. 2011.]</ref>.
Microbial communities change quite a bit during the malting process. It is thought that the factors affecting this are the initial microbe populations, interactions between species, the variances in the malted barley characteristics/processes, and additives. Different malting houses are likely to form "in-house" microflora populations. The first step in malting, which is steeping, sees the first large change in microbial populations. The steeping process favors lactic acid bacteria (LAB), which are seen in extremely small numbers before steeping. Particularly these are ''Leuconostoc'' species. In the case of yeasts, ''Basidiomycota'' fungi grow, as wellas ''Fusarium'' <ref name="Lievens1"></ref>.
The second step of malting, which is germination, sees starches converted to sugars, which causes microbial populations to increase once again. Where ''Leuconostoc'' species of bacteria were dominate during steeping, the germination process is where [[Lactobacillus]] species begin to dominate the microbial community. A greater diversity of species also occurs during this step in malting. As far as fungi, ''Ascomycetous'' yeasts begin to dominate, where as ''Alternaria'' and ''Cladosporium'' decline <ref name="Lievens1"></ref>.
During kilning, microbial populations are reduced by a factor of 10-100, but are still higher than that of field barley. The high degree of variability is dependent on the kilning temperature and procedure. Heat resistant microbes, perhaps by forming biofilms, can survive the hot temperatures. These include ''Rhizopus'' and ''Mucor'' species <ref name="Lievens1"></ref>.
===Malted Barley===
(In Progress)
==See Also==
===Additional Articles on MTF Wiki===
* [[Alternative_Bacteria_Sources#Culturing_Lactobacillus_From_Grains|Culturing Lacto From Grains]]
===External Resources===
* [http://www.homebrewtalk.com/wiki/index.php/Grain Homebrew Talk Wiki page on Grain.]
==References==
<references/>
[[Category:Ingredients]]
==Microbial Populations on Barley==
===Malting Process==
Microbial communities found on barley are very diverse and change significantly throughout the malting process, with more diversity occurring further along in the malting process. In the barley fields, Gram-negative bacteria (especially ''Erwinia herbicola'') are abundant. Climate is said to have the most impact on which species grow in barley fields. For example ''Fusarium'' species are encouraged by high humidity, and are associated with mycotoxins and gushing problems in beer. During dry storage of barley, spore forming bacteria tend to survive. Xerophilic fungi (fungi that doesn't need much water) also survive on dry barley during storage <ref name="Lievens1">[https://lirias.kuleuven.be/bitstream/123456789/323403/2/Just%C3%A9%20et%20al.%202011_Microflora%20during%20Malting%20of%20Barley%20Overview%20and%20Impact%20on%20Malt%20Quality.%20Brewing%20Science%2064,%2022-31..pdf Microfl ora during Malting of Barley: Overview and Impact on Malt Quality. A. Justé, S. Malfl iet, M. Lenaerts, L. de Cooman, G. Aerts, K. A. Willems and B. Lievens. 2011.]</ref>.
Microbial communities change quite a bit during the malting process. It is thought that the factors affecting this are the initial microbe populations, interactions between species, the variances in the malted barley characteristics/processes, and additives. Different malting houses are likely to form "in-house" microflora populations. The first step in malting, which is steeping, sees the first large change in microbial populations. The steeping process favors lactic acid bacteria (LAB), which are seen in extremely small numbers before steeping. Particularly these are ''Leuconostoc'' species. In the case of yeasts, ''Basidiomycota'' fungi grow, as wellas ''Fusarium'' <ref name="Lievens1"></ref>.
The second step of malting, which is germination, sees starches converted to sugars, which causes microbial populations to increase once again. Where ''Leuconostoc'' species of bacteria were dominate during steeping, the germination process is where [[Lactobacillus]] species begin to dominate the microbial community. A greater diversity of species also occurs during this step in malting. As far as fungi, ''Ascomycetous'' yeasts begin to dominate, where as ''Alternaria'' and ''Cladosporium'' decline <ref name="Lievens1"></ref>.
During kilning, microbial populations are reduced by a factor of 10-100, but are still higher than that of field barley. The high degree of variability is dependent on the kilning temperature and procedure. Heat resistant microbes, perhaps by forming biofilms, can survive the hot temperatures. These include ''Rhizopus'' and ''Mucor'' species <ref name="Lievens1"></ref>.
===Malted Barley===
(In Progress)
==See Also==
===Additional Articles on MTF Wiki===
* [[Alternative_Bacteria_Sources#Culturing_Lactobacillus_From_Grains|Culturing Lacto From Grains]]
===External Resources===
* [http://www.homebrewtalk.com/wiki/index.php/Grain Homebrew Talk Wiki page on Grain.]
==References==
<references/>
[[Category:Ingredients]]