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They also established that the volatility of DMS is the same regardless of the gravity of the wort and that it is instead affected by temperature, atmospheric pressure, and the concentration of DMS (higher concentration of DMS slightly raises the volatility of DMS). For non-wort solutions, 10% sucrose in water greatly increased the volatility of DMS, possibly due to a [http://chemwiki.ucdavis.edu/Core/Physical_Chemistry/Thermodynamics/Non-Ideal_Systems/Salting_Out salting-out effect] of sucrose which leads to a higher evaporation rate for DMS molecules <ref name="Scheuren2016mbaa"></ref>. A larger top surface area will allow for faster evaporation of the total DMS present in the wort, but the total DMS present in the wort would eventually be evaporated off regardless of what the top surface area of the kettle is <ref name="Scheuren2016"></ref>. In order to limit DMS in the end product, it is advised to allow no more than 100 µg/L of DMS into the fermenter <ref name="Scheuren2016mbaa">Influence of Extract on Volatility of Flavor Components in Wort During Open and Closed Boil. Hans Scheuren Roland Feilner, Frank-Jürgen Methner, and Michael Dillenburger. MBAA website. 2016.</ref>.
Much of the DMS in wort that is formed during the wort production process is volatilized off during fermentation due to off-gassing of CO2CO<sup>2</sup. However, if high amounts of DMS survive the boil, then the off-gassing from fermentation may not be enough to volatilize all of the DMS. The shape and type of the fermenter also play a role in how much DMS is volatilized during fermentation, for example, Anderson et al. and Booer & Wilson showed that open fermentation leads to less DMS compared to closed fermentation <ref name="Anness"></ref>. Higher fermentation temperatures (18°C versus 9-12°C, for example) can lead to higher rates of DMS volatilization <ref name="narziss2008">[http://www.wiley.com/WileyCDA/WileyTitle/productCd-3527659889.html Die Bierbrauerei: Band 2: Die Technologie der Würzebereitung, 8 Auflage. Ludwig Narziss. 2008. Section 5.6.4.3.]</ref>. DMS can spike towards the end of fermentation from yeast metabolizing DMSO into DMS (see [[Dimethyl_Sulfide#DMSO_Precursor|DMSO Precursor]]) <ref name="Anness"></ref>.
==Short Boils and Raw Ale==
[[Raw Ale|Raw ale]], also referred to as "no-boil", is a method of wort production that involves not boiling the wort, or perhaps by some definitions, very short boils <ref name="larsblog">[http://www.garshol.priv.no/blog/331.html Raw ale. Lars Marius Garshol. Larsblog. 06/05/2016. Retrieved 03/02/2016.]</ref>. Although mainly a historical method of brewing, this style of brewing has recently become popular in the production of [[Berliner Weissbier]] and other styles of beer using [[Wort_Souring|wort souring or kettle souring]] methods. Many recipes for these styles of beer call for pilsner malts to be used, which can contain higher amounts of SMM precursor. An often asked question about no-boil/raw ales and wort boiled for 15 minutes or less is: are there concerns about DMS production?
Anecdotal reports of no issues with DMS in these types of beers seem to far outweigh the reports of DMS problems <ref>[http://brulosophy.com/2015/10/08/update-lab-data-on-pils-malt-boil-length-exbeeriment/ "Update: Lab Data on Pils Malt Boil Length Exbeeriment" on Brulosophy. Retrieved 03/08/2016.]</ref><ref>[http://beerandwinejournal.com/30-min-boil/ "All Grain Pale Ale 30-Minute Boil Experiments" by James Spencer on Beer & Wine Journal. 06/24/2015. Retrieved 03/08/2016.]</ref><ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1243791188982426/ Discussion on MTF regarding DMS in raw ale/no boil/short boils. 03/01/2016.]</ref><ref name="larsblog"></ref>. The specific nature of (or lack of) DMS detection in no-boil/raw ale has not been widely explored by science. There are, however, some explanations that have been proposed. For example, when boiling smaller volumes of wort such as on the homebrew scale there is a larger surface area to volume ratio. This larger surface area to volume ratio allows for more evaporation and volatilization of DMS to occur <ref name="beersmith">[https://www.youtube.com/watch?v=YDBKUCkg8cM Boiling Home Brewed Beer with Dr Charlie Bamforth - BeerSmith Podcast #121.]</ref> (~30 minutes in). Smaller fermenters would also benefit from a larger surface area to volume ratio since CO2 CO<sup>2</sup from fermentation volatilize DMS. This may account for the general lack of DMS reported in homebrewed and small-scale farmhouse beer.
Commercial brewers performing no-boil beers have also often reported a lack of DMS issues in their beer <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1367101639984713/ Poll to commercial brewers on MTF on getting DMS in no-boil beers. 08/04/2016.]</ref><ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1243791188982426/?comment_id=1251233804904831&reply_comment_id=1251348394893372&comment_tracking=%7B%22tn%22%3A%22R9%22%7D Conversation with Jeff Crane from Council Brewing Co on no-boil and DMS. 03/12/2016.]</ref>. There are likely other factors at play that limit the amount of DMS produced. Specifically, the conversion of SMM to DMS happens extremely slowly at temperatures under 95°C, which would result in less DMS being produced during no-boil brewing. DMS is also very volatile in the temperature range of 50-100°C. See [[Dimethyl_Sulfide#Volatility_of_DMS|DMS Volatility]] and [[Dimethyl_Sulfide#DMS_Prediction_Models|DMS Prediction Models]] for more information on why DMS is probably not an issue with no-boil beers.