DMS and kettle souring

[tiredofbuyingbeer]

I'm kettle souring a gose, but I don't want DMS. If I plan on boiling after the kettle sour, will I get DMS if I don't boil or reach a sufficiently temperature after mashing but before kettle souring?

 

[radwizard]

You'll get DMS if you boil for a very short time, or heat it up to much in your pasteurization. It is my understanding, if you want to do a no boil then mash low, sour, and pitch. If you want to kill the microbes and halt the souring, then do a full boil.

Im sure a lot of different people have opinions on this, but the is a lot of DMS in Berliners and Gose that I have tasted. I do the full 60 boil following kettle souring. I am not really interested so much in the no boil method, but If I wanted to give it a go I would keep the microbes alive and not re heat it.

Most of these beers use Pilsner as well which do produce more DMS, although the time required to boil it off is debatable. I do 60 minute boils and havent had issue with DMS in kettle sours.

 

[tiredofbuyingbeer]

Maybe I wasn't clear. Let's say I've decided to do a normal 60 minute boil once the beer is soured. If I'm going to do that, do I also need to boil beforehand to avoid DMS? The alternative I'm considering would be to pasteurize in the mid-180s for 10 minutes or so before pitching the lacto.

 

[radwizard]

Yeah, that should be good. I always have Mashed, Adjusted Lactic, Boil for a few minutes, Pitch Lacto, Full Length Boil, Pitch Yeast.

 

[RM-MN]

You get DMS if your grains contain SMM and it isn't boiled off. Many modern malts have little SMM and short boils may be sufficient to remove the DMS. I've been doing 30 minute boils without any noticeable DMS (not noticeable to me anyway, not sent to competitions).

 

[mabrungard]

All barley contains SMM. It's not going to transform to DMS without heat. The Milk the Funk website has a nice write up on the relationship between SMM and DMS and scenarios for reducing DMS when brewing sour beers that have little bittering. It turns out that you can use either extreme...no boil or a regular boil and achieve a similar low DMS result.

It turns out that a typical boil will convert almost all of the SMM to DMS in about 30 minutes. So boiling for less than 30 minutes can be problematic. But a number of brewers have experimented with 30 minute boils and have found that DMS was not a big problem, even with pils malt. Its that shorter duration that could vex you. The Milk the Funk page does indicate that a no boil approach can work for sterilizing wort and avoiding DMS.

 

[radwizard]

All barley contains SMM. It's not going to transform to DMS without heat. The Milk the Funk website has a nice write up on the relationship between SMM and DMS and scenarios for reducing DMS when brewing sour beers that have little bittering. It turns out that you can use either extreme...no boil or a regular boil and achieve a similar low DMS result.

It turns out that a typical boil will convert almost all of the SMM to DMS in about 30 minutes. So boiling for less than 30 minutes can be problematic. But a number of brewers have experimented with 30 minute boils and have found that DMS was not a big problem, even with pils malt. Its that shorter duration that could vex you. The Milk the Funk page does indicate that a no boil approach can work for sterilizing wort and avoiding DMS.

Good stuff. I am under the impression that a lot of bad kettle soured beer is from the brewer boiling for 5-10 minutes before and after souring for pasteurization. I always have done the full 60 minutes after the souring, I just have to much time invested in the mashing and souring process to feel comfortable shorting that time.

As for pre souring pasteurization, the DMS (if it was boiled) created shouldn't effect the actual LAB preformance, and would eventually be boiled off during a 60 minute post souring boil -- is the correct?
Thanks!

 

[mabrungard]

With typical mashing temperatures, it just doesn't seem necessary to pasteurize the pre-soured wort. Most organisms can't survive more than 15 minutes of 150F+ temps. I typically mash out at 168F and that makes it even less likely that there is a wort spoiler in there. I just run off that hot wort into my keg and allow it to cool to lacto temp and then pitch my lacto starter. Of course, I also acidify that wort to around 4.5 so that other spoiling organisms are retarded and the lacto will become the dominant species.

 

[radwizard]

I pre-acidify as well, but also employ a short (10-15 minute) boil before souring. I started doing this after reading a Matt Miller updated article on fast souring techniques. There seems to be a number of people that report problems during fermentation that have neglected a short boil before souring. I am sure this is also heavily based on process. (for example I am BIABing these beers at lower mash temps)
Some of the theory's brewers have come up with to why this was happening included Wort Chemistry, and pockets in the mash where temperatures were much lower (including dough balls)

I have kind of settled on the pre-boil to safe guard any of these issues. I have had nothing but positive results from my kettle sour process, but honestly I don't know it the pre-souring boil is responsible for any of it. It has just became part of my method.