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Thread: DMS from Weyermann

  1. #1
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    DMS from Weyermann

    Hey all,

    anyone experienced problems with DMS in recent batches of Weyermann malt?
    I am not really sure where to look for the problem, because we keep getting DMS in one of our beers but not in the others.
    cooling time + boiling time is always equal for all different beers but only one shows signs of DMS

    The ONLY difference between the beer in question and others is that we included oats in the grist but to the best of my knowledge there are no precursors in Oats.
    -e

  2. #2
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    Are you seeing the same rate of evaporation in the beers? Roughly 6%+ per hour or 9%+ over 1.5 hours? Does the style in question contain a higher percentage of lightly kilned malts (Pils, 2 Row)? Oats are not known to contain high levels of S-methylmethionine as far as my limited knowledge of them.

    You may consider moving that particular beer to a longer boil if you are not at 1.5 hours. There is a significant reduction from SMM to DMS and evaporation (something like 38% more) between one hour and 1.5 that takes place. My Weyermann is not necessarily a "recent batch" but less than 6 months old. Have not experienced any issues, but we usually run a 1.5hr boil.

    If you are seeing the DMS with ONLY the oats being different, what makes you suspect Weyermann malts? It the only Weyermann the oats? I would tend to suspect the oats by process of elimination at that point.

  3. #3
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    Like UnFermentable said, I have worked with Weyermann malt during most of my career. If you use their pilsner, whether is premium, bohemian, floor malted or regular shoot for a 90 minute boil. you will get rid of up to 78% if not wrong when boil for 90 minutes.

  4. #4
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    Nov 2010
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    Ninety minute boils are not always necessary for reducing DMS in beers, even with pils malt. DMS is a product of SMM, which is prevalent in very lightly kilned malt such as pils. SMM is converted to DMS in the boil. But SMM is converted to negligible levels in wort in as little as about 30 minutes in boils at sea-level and with a modest wort pH of about 5.4 or above. Once the SMM is converted to DMS, its readily volatilized out of the wort.

    Reduction in the conversion rate of SMM to DMS occurs as wort pH is reduced and when your brewery's elevation is higher. Dropping wort pH to around 5.2 decreases the SMM conversion rate by about 15 to 20 percent. But elevation has a pretty substantial effect on the conversion rate since the boiling temperature drops with elevation and the conversion is temperature-dependent. The SMM conversion rate drops by about half if your brewery is at 5000 ft compared to the sea-level conversion rate. It gets worse, if your brewery is higher than that.

    Your kettle's evaporation loss is another factor in reducing DMS in wort. While energy efficiency is an important consideration in brewery operations, having an adequate evaporation loss is important in reducing DMS. My experience is that achieving at least 6 percent evaporation loss during the boil should be close to eliminating DMS, but you might have to bump that to 8 or 10 percent in some cases. You can conduct a relatively quiet (lightly rolling) boil for much of the duration in order to avoid heat stress on your wort and keep your TBI low. But, you should bump up the boil vigor in the last ten minutes or so and keep the kettle shutter (lid) open in order to maximize volatilization and carry-out of DMS-laden steam.

    Another factor is the yeast that you're using. Some yeasts do produce DMS as part of their metabolism.

    So, take a look at your wort pH and make sure its not too low during the boil. Also, be aware of your brewery's elevation and the effects that has on SMM conversion and therefore: DMS content. If your brewery isn't at high elevation and the wort pH isn't too low, maybe a change in yeast could help your situation. Check these factors before assuming that a 90 minute boil length is the solution. Boiling too long and with too much vigor will increase your wort TBI and that has a direct effect on beer longevity.
    WaterEng
    Engineering Consultant
    BrunSolutions.com

  5. #5
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    I think this is great information for sure, but I am not convinced it has that much impact on the longevity of beer life. Perhaps because my boils were not too vigorous, perhaps because three of the four were low pressure steam systems, or perhaps my beers weren't out long enough to notice, but as long as I reach 9-10% evaporation there was no DMS character at 90 mins and beer life reached my desired length of time, 3-4 months (probably longer). I didn't test beyond that as I have never had beer out older than that. There are many other factors I deem much more important to longevity before I worry about TBI personally, but my breweries are not reaching into other states or beyond.

    Personal experience from boiling both 60 and 90 mins at sea level (125m, and 8m) and at higher altitudes (920m, 1,655m, and 1,553m) at temps ranging from 97-101*C has shown me consistently that 60 mins has potential to leave behind DMS. 90 mins has never given noticeable DMS even in Pilsner, Kolsch and Helles. I have never evaporated 9% in 60 mins, so that may be why I have not seen issues associated with high TBI.

    As WaterEng says, some yeast can produce DMS, so if the strain on these exhibiting beers is different than others that don't have it, you might want to consider a change there first.

  6. #6
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    Quote Originally Posted by UnFermentable View Post
    Are you seeing the same rate of evaporation in the beers? Roughly 6%+ per hour or 9%+ over 1.5 hours? Does the style in question contain a higher percentage of lightly kilned malts (Pils, 2 Row)? Oats are not known to contain high levels of S-methylmethionine as far as my limited knowledge of them.

    You may consider moving that particular beer to a longer boil if you are not at 1.5 hours. There is a significant reduction from SMM to DMS and evaporation (something like 38% more) between one hour and 1.5 that takes place. My Weyermann is not necessarily a "recent batch" but less than 6 months old. Have not experienced any issues, but we usually run a 1.5hr boil.

    If you are seeing the DMS with ONLY the oats being different, what makes you suspect Weyermann malts? It the only Weyermann the oats? I would tend to suspect the oats by process of elimination at that point.
    Indeed - process of elimination lead me to the oats as well - but done a fair bit of research and asking around (who know their stuff well enough to trust) and couldnt find any reason to believe that SSM (and thus DMS) should be an issue with flaked oats. We do a standard 75 boil but have also upped it to 90 past few brews.

    We switched from a wit strain to US-05 because I suspected yeast as well. same issue

    So strangely enough - I have now taken the oats out for the last batch and low-and-behold. no DMS.
    This is hurting my brain a little bit... Glad to have (hopefully?) found the issue but really wish I had a bit of science to back this up.

  7. #7
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    I've heard of folks having higher than expected sulfur production with US-05. Is it possible that it is a fermentation-derived sulfur compound? We cool-ferment (62F) WY1056 for our Blonde and it produces some noticeable sulfur that, for us, scrubs and ages out during transfers, brite tank storage and carbonation. Does the compound present itself as cooked cabbage/veggies/tomato or more farty or boiled eggs?

    Cheers,
    Tom

  8. #8
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    Quote Originally Posted by BemidjiBrewing View Post
    I've heard of folks having higher than expected sulfur production with US-05. Is it possible that it is a fermentation-derived sulfur compound? We cool-ferment (62F) WY1056 for our Blonde and it produces some noticeable sulfur that, for us, scrubs and ages out during transfers, brite tank storage and carbonation. Does the compound present itself as cooked cabbage/veggies/tomato or more farty or boiled eggs?

    Cheers,
    Tom
    I think, you missed that he switched from originally using a Wit to US-05. If both are giving him the DMS character it is most likely the oats. It is usually quite easy to tell the difference between DMS and sulphur.

    You could try a different oats supplier? I have used many but tend to like Briess the best. Their oats always smell so fresh and taste good. Fawcett is my number two. SMM is an amino acid that is formed during germination, so perhaps a different maltster may process the oats differently, thereby reducing SMM content and the potential of SMM to DMS.

    Also, you don't leave the wort warm for extended periods after boiling do you? The SMM conversion can continue to take place after boil if you don't chill the wort quickly. Haven't found this to be evident after the 90 min boils though (10 min WP and 20 min Rest), as you likely have converted and driven off most of the potential.

  9. #9
    Join Date
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    Quote Originally Posted by WaterEng View Post
    Ninety minute boils are not always necessary for reducing DMS in beers, even with pils malt. DMS is a product of SMM, which is prevalent in very lightly kilned malt such as pils. SMM is converted to DMS in the boil. But SMM is converted to negligible levels in wort in as little as about 30 minutes in boils at sea-level and with a modest wort pH of about 5.4 or above. Once the SMM is converted to DMS, its readily volatilized out of the wort.

    Reduction in the conversion rate of SMM to DMS occurs as wort pH is reduced and when your brewery's elevation is higher. Dropping wort pH to around 5.2 decreases the SMM conversion rate by about 15 to 20 percent. But elevation has a pretty substantial effect on the conversion rate since the boiling temperature drops with elevation and the conversion is temperature-dependent. The SMM conversion rate drops by about half if your brewery is at 5000 ft compared to the sea-level conversion rate. It gets worse, if your brewery is higher than that.

    Your kettle's evaporation loss is another factor in reducing DMS in wort. While energy efficiency is an important consideration in brewery operations, having an adequate evaporation loss is important in reducing DMS. My experience is that achieving at least 6 percent evaporation loss during the boil should be close to eliminating DMS, but you might have to bump that to 8 or 10 percent in some cases. You can conduct a relatively quiet (lightly rolling) boil for much of the duration in order to avoid heat stress on your wort and keep your TBI low. But, you should bump up the boil vigor in the last ten minutes or so and keep the kettle shutter (lid) open in order to maximize volatilization and carry-out of DMS-laden steam.

    Another factor is the yeast that you're using. Some yeasts do produce DMS as part of their metabolism.

    So, take a look at your wort pH and make sure its not too low during the boil. Also, be aware of your brewery's elevation and the effects that has on SMM conversion and therefore: DMS content. If your brewery isn't at high elevation and the wort pH isn't too low, maybe a change in yeast could help your situation. Check these factors before assuming that a 90 minute boil length is the solution. Boiling too long and with too much vigor will increase your wort TBI and that has a direct effect on beer longevity.
    Could the low pH in kettle sours cause DMS in the finished beer?

  10. #10
    Join Date
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    Quote Originally Posted by BemidjiBrewing View Post
    I've heard of folks having higher than expected sulfur production with US-05. Is it possible that it is a fermentation-derived sulfur compound? We cool-ferment (62F) WY1056 for our Blonde and it produces some noticeable sulfur that, for us, scrubs and ages out during transfers, brite tank storage and carbonation. Does the compound present itself as cooked cabbage/veggies/tomato or more farty or boiled eggs?

    Cheers,
    Tom
    no, its definitely corn and cabbage

  11. #11
    Join Date
    Nov 2010
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    Quote Originally Posted by Gbbc View Post
    Could the low pH in kettle sours cause DMS in the finished beer?
    SMM conversion to DMS is highly impeded by low pH. Some brewers are resorting to not converting SMM in their sour beers, by just raising the wort to a sterilizing temp for say 15 minutes and then fermenting.
    WaterEng
    Engineering Consultant
    BrunSolutions.com

  12. #12
    Join Date
    Apr 2014
    Location
    US
    Posts
    31

    Yes, had to dump. Also, no response from my supplier or Weyerman

    We brew a Bohemian Pilsner and have for two years including 20 or so batches using Best and Avangard German Pils. I wanted to try a batch with Weyermann Floor-Malted Bohemian Pils and it was a DMS bomb from day 1. We got zero micro hits and I sent a sample to a large brewery to check for DMS on their Gas Chromatograph. Needless to say it was 4-5 times the level of their normal pilsner beer readings. We changed nothing in the process, 90 minute rolling boil as always. We concluded the DMS precursors must be through the roof on this malt and we needed a super hard boil for even longer with a quick whirlpool and knock-out. I would love to have Weyermann respond but I cant get any response from them after sending emails and leaving messages and my BSG (distributor) rep is AWOL. Ill be sticking with the other malts for my pils base beers. Due to the posts here I will look back again and check this pre-boil PH. We will also monitor ph closer pre-boil but we almost always boil at 5.4-5.5.
    Last edited by RockyMtnBrew; 10-17-2017 at 06:32 PM.

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