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Dimethyl Sulfide

641 bytes added, 12:56, 23 March 2016
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[[File:DMS Pasteurization.png|none|thumb|500px|SMM conversion to DMS during a 20 minute heat up, 15 minute pasteurization at 82°C, and 60 minute cool down to 20°C. Graph created and provided by [https://www.facebook.com/mark.hammond.1253 Mark Hammond].]]
In the above computer generated graph based on the half-life rates of SMM, only ~60 µg/L of SMM is converted into very little DMS. Even if a closed cooling system were to be used, only ~60 6 µg/L of DMSwould be retained. This is below demonstrates the recommended threshold of 100 µg/L very slow decomposition of SMM into DMS that should be allowed to enter the fermenter <ref name="Scheuren2016mbaa"></ref>at below boiling temperatures.
Hammond also generated graphs for a 15 minute boil and a "0 minute" boil (wort heated to 100°C, then immediately cooled). These graphs are seen below:
[[File:DMS 0MinBoil.png|none|thumb|500px|SMM conversion to DMS during a 20 minute heat up to boiling temperature (100°C), then immediate cooling for 60 minutes to 20°C ("0 minute" boil). Graph created and provided by [https://www.facebook.com/mark.hammond.1253 Mark Hammond].]]
In the case of the 15 minute boil, approximately 400 350 µg/L of SMM is converted into approximately 400 about 40 µg/L of DMS. During 15 minutes of boiling appears not to be long enough to efficiently boil off the boiling processcreated DMS, it could however in an open cooling system much of the DMS will still be assumed that much evaporated during cooling (see [[Dimethyl_Sulfide#Volatility_of_DMS|DMS Volatility]]). Even if the wort was cooled in a closed system and this amount of DMS was retained in the wort, 40 µg/L of DMS is volatilized due still below the recommended threshold of 100 µg/L of DMS that should be allowed to enter the boilfermenter <ref name="Scheuren2016mbaa"></ref>.  In the case of the "0 minute" boil, approximately 175 µg/L of SMM is converted into approximately 175 20 µg/L of DMS. Just as in the other examples, the DMS continues to volatilize below boiling temperatures in an open cooling system (see [[Dimethyl_Sulfide#Volatility_of_DMS|DMS Volatility]]). Even if the wort was cooled in a closed system and this amount of DMS was retained in the wort, so some evaporation 20 µg/L of DMS is still below the created recommended threshold of 100 µg/L of DMS will still occur in that should be allowed to enter the fermenter <ref name="0 minuteScheuren2016mbaa" example in an open cooling system></ref>.
For comparison sake, a graph of a 60 minute boil is shown below:

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