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Milling: Difference between revisions
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===Oxidation=== | ===Oxidation=== | ||
[[File:Mill-on-cooler.jpg|thumb|right|Mill with base on top of a cooler mash tun]] | [[File:Mill-on-cooler.jpg|thumb|right|Mill with base on top of a cooler mash tun]] | ||
The grist begins to [[Oxidation|oxidize]] immediately upon milling (because the inside of the kernels are then exposed to air and moisture) and this can have a negative impact on the subsequent beer quality.<ref name="Kunze"/><ref name=adb/><ref name=golston>Golston AM. The impact of barley lipids on the brewing process and final beer quality: A mini-review. ''Tech Q Master Brew Assoc Am.'' 2021;58(1):43–51.</ref> | The grist begins to [[Oxidation|oxidize]] immediately upon milling (because the inside of the kernels are then exposed to air and moisture) and this can have a negative impact on the subsequent beer quality.<ref name="Kunze"/><ref name=adb/> Therefore the time between milling and dough-in should be kept as short as possible.<ref name=golston>Golston AM. The impact of barley lipids on the brewing process and final beer quality: A mini-review. ''Tech Q Master Brew Assoc Am.'' 2021;58(1):43–51.</ref> | ||
Modern commercial low oxygen breweries fill all areas containing milled grain with inert gas (CO<sub>2</sub> or N<sub>2</sub>) to prevent oxygen exposure.<ref name="Kunze"/><ref name=bsp/><ref name=adb/><ref name=derouck/> Brewers looking to [[low oxygen brewing|preserve fresh grain flavor]] may also attempt this by flowing inert gas into the bottom of the mash tun and milling directly into it, or by flushing the grist with inert gas after milling.<ref name=stephenson>Stephenson WH, Biawa JP, Miracle RE, Bamforth CW. [https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416.2003.tb00168.x Laboratory-scale studies of the impact of oxygen on mashing.] ''J Inst Brew.'' 2003;109(3):273–283.</ref><ref name=mullerr>Muller R. [https://www.tandfonline.com/doi/abs/10.1094/ASBCJ-53-0053 Use of 5,5’-dithiobis (2-nitrobenzoic acid) as a measure of oxidation during mashing.] ''J Am Soc Brew Chem.'' 1995;53(2):53–58.</ref><ref>[http://www.lowoxygenbrewing.com/forum/viewtopic.php?f=2&t=1025 CO2 purge of mash tun prior to underletting?] Low Oxygen Brewing forum. 2018. Accessed 2020.</ref><ref name="lob1394">[http://www.lowoxygenbrewing.com/forum/viewtopic.php?f=18&t=1394 Milling into mash tun.] Low Oxygen Brewing forum. 2019. Accessed 2020.</ref> Purging a mostly covered mash tun at 1–2 psi for about 10 minutes has been shown to effectively remove the vast majority of oxygen in the vessel.<ref>[http://www.lowoxygenbrewing.com/forum/viewtopic.php?f=11&t=751 Purging grist in the tun.] Low Oxygen Brewing forum. 2018. Accessed 2020.</ref> A regulator may start to freeze up and/or significantly chill the mash tun parts, causing dough-in temperature to be too low. A fix for that is to get a cheap heat lamp or hair dryer and point it at your regulator.<ref name="lob1394"/> Dry ice can also be used to purge: put the dry ice in a jar with water and connect it with tubing to the mash tun. | Modern commercial low oxygen breweries fill all areas containing milled grain with inert gas (CO<sub>2</sub> or N<sub>2</sub>) to prevent oxygen exposure.<ref name="Kunze"/><ref name=bsp/><ref name=adb/><ref name=derouck/> Brewers looking to [[low oxygen brewing|preserve fresh grain flavor]] may also attempt this by flowing inert gas into the bottom of the mash tun and milling directly into it, or by flushing the grist with inert gas after milling.<ref name=stephenson>Stephenson WH, Biawa JP, Miracle RE, Bamforth CW. [https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416.2003.tb00168.x Laboratory-scale studies of the impact of oxygen on mashing.] ''J Inst Brew.'' 2003;109(3):273–283.</ref><ref name=mullerr>Muller R. [https://www.tandfonline.com/doi/abs/10.1094/ASBCJ-53-0053 Use of 5,5’-dithiobis (2-nitrobenzoic acid) as a measure of oxidation during mashing.] ''J Am Soc Brew Chem.'' 1995;53(2):53–58.</ref><ref>[http://www.lowoxygenbrewing.com/forum/viewtopic.php?f=2&t=1025 CO2 purge of mash tun prior to underletting?] Low Oxygen Brewing forum. 2018. Accessed 2020.</ref><ref name="lob1394">[http://www.lowoxygenbrewing.com/forum/viewtopic.php?f=18&t=1394 Milling into mash tun.] Low Oxygen Brewing forum. 2019. Accessed 2020.</ref> Purging a mostly covered mash tun at 1–2 psi for about 10 minutes has been shown to effectively remove the vast majority of oxygen in the vessel.<ref>[http://www.lowoxygenbrewing.com/forum/viewtopic.php?f=11&t=751 Purging grist in the tun.] Low Oxygen Brewing forum. 2018. Accessed 2020.</ref> A regulator may start to freeze up and/or significantly chill the mash tun parts, causing dough-in temperature to be too low. A fix for that is to get a cheap heat lamp or hair dryer and point it at your regulator.<ref name="lob1394"/> Dry ice can also be used to purge: put the dry ice in a jar with water and connect it with tubing to the mash tun. | ||