How to prevent DMS

[Beer-lord]

I read an interesting article about preventing DMS that some may find helpful. One thing I noticed was the mention that long hopstands and whirlpooling could cause DMS to form, especially when doing short boils. Some parts of this article are obvious but there is some good info here.
http://scottjanish.com/how-to-prevent-dms-in-beer/

[mashani]

"I’m also going to start experimenting with putting a piece of tinfoil over the small carboy opening on my Big Mouth Bubblers during the aggressive stage of fermentation and replace it with an airlock after around days 3-5. When I ferment in a keg, I might consider leaving the pressure release valve open to mimic an open fermentation to encourage more DMS removal by C02."

So, I do a lot of "bad" things - short boils, lid-on hop stands (slow chilling) or no chill sometimes.

One thing I never do is airlock my fermenters. I put a lid on them fitted loosely. If I was using a big mouth I'd just put a stopper in the lid, set the lid on top and give it just 1/8th a turn or so it doesn't just pop off, and let it go. If I used a bucket, I'd just be covering the top with tinfoil. All I want is just basically acts as a free venting "lip" that sits over the edge of the fermenter body, it is just there to keep dog and cat hair and anything else floating in my air from falling down into the fermenter. My fermenters never pressurize. It is a lot like open fermenting. I didn't do this intentionally to vent DMS, but started doing it because I like the ester profile results better for yeast where I want them, but kept doing it for all beers because I seem to get better attenuation levels, and seem to ferment more vigorously, and in the case where my house Brett gets into it, I will see a pellicle form rapidly (as early as day 9 or 10), so I know what I'm dealing with come bottling time.

I don't seem to ever have DMS problems. Nobody who has ever tried my beer has commented on DMS either.

Other factors that could be helping me out is that my short boil beers tend to be partial mash + extract, or extract + steep batches. So the extract might already be somewhat DMS purged as such, so only 1/3rd or so of my batch might be an issue for the short boil. Sometimes my partial mash was made ahead of time, and that was actually boiled for 20-30 minutes or so (but then usually NO CHILLED, which should be DMS issue in theory) and then put into containers and frozen for future use. When I do a full BIAB mash, I am typically still boiling it for 45 minutes or more.

Another one is that if you look at this yeast pitch rate calculator:

http://www.brewersfriend.com/yeast-pitc ... alculator/

I am pitching my yeast at what they call "Pro 0.75" or "Pro 1.0" pitch rates for the most part. Which is a lot of yeast.

So it seems that some combination of the free venting and lots of yeast and perhaps using some extract keeps the beast at bay for me.

My fermentations are actually usually done in 3-7 days. I just keep a 2 week rotation because that timing works for me for other reasons, IE the "Brett detection" I mentioned above.

[The_Professor]

.....One thing I never do is airlock my fermenters. I put a lid on them fitted loosely. If I was using a big mouth I'd just put a stopper in the lid, set the lid on top and give it just 1/8th a turn or so it doesn't just pop off, and let it go. If I used a bucket, I'd just be covering the top with tinfoil. All I want is just basically acts as a free venting "lip" that sits over the edge of the fermenter body, it is just there to keep dog and cat hair and anything else floating in my air from falling down into the fermenter.....

viewtopic.php?f=7&t=11&start=2220#p86595

I bottled my "Oak Smoked Strong Golden Ale with Cherry and Wheat" - which got enhanced with the Brett C strain that lives in my house. Luckily I like it and embrace the funk.....

Hmmmmmm, possible connection?

[Inkleg]

.....One thing I never do is airlock my fermenters. I put a lid on them fitted loosely. If I was using a big mouth I'd just put a stopper in the lid, set the lid on top and give it just 1/8th a turn or so it doesn't just pop off, and let it go. If I used a bucket, I'd just be covering the top with tinfoil. All I want is just basically acts as a free venting "lip" that sits over the edge of the fermenter body, it is just there to keep dog and cat hair and anything else floating in my air from falling down into the fermenter.....

viewtopic.php?f=7&t=11&start=2220#p86595

I bottled my "Oak Smoked Strong Golden Ale with Cherry and Wheat" - which got enhanced with the Brett C strain that lives in my house. Luckily I like it and embrace the funk.....

Hmmmmmm, possible connection?

Nope. If Dave's beer is gonna get Brett it won't matter if it's a loose lid, tin foil, open ferment or in a Negative Sealed Pressure Level 4 Sanitized Sterilized Fermenter. When Brett lives in your house, you pitch and pray.

[mashani]

.....One thing I never do is airlock my fermenters. I put a lid on them fitted loosely. If I was using a big mouth I'd just put a stopper in the lid, set the lid on top and give it just 1/8th a turn or so it doesn't just pop off, and let it go. If I used a bucket, I'd just be covering the top with tinfoil. All I want is just basically acts as a free venting "lip" that sits over the edge of the fermenter body, it is just there to keep dog and cat hair and anything else floating in my air from falling down into the fermenter.....

viewtopic.php?f=7&t=11&start=2220#p86595

I bottled my "Oak Smoked Strong Golden Ale with Cherry and Wheat" - which got enhanced with the Brett C strain that lives in my house. Luckily I like it and embrace the funk.....

Hmmmmmm, possible connection?

Nah, Inkleg has it right. The only connection is this:

in the case where my house Brett gets into it, I will see a pellicle form rapidly (as early as day 9 or 10), so I know what I'm dealing with come bottling time.

The brett can't "fall in" because of the lid. It can't "climb up" under the lid, because it is physically unable to do so. They can't blow in sideways because of the lip over the edge. Beer infecting organisms do not have motile cilia and/or flagella, so they can't crawl up under things. The simply float in the air and fall "downwards". Typically, only if they fall down into something can they get in. Unless they live in whatever you put your beer into (IE a barrel).

So pretty much if it has Brett it's because it fell in while my wort was cooling and/or being transferred into my fermenter and/or because I popped off that lid and dry hopped the beer or for some other reason (feeding sugar, what not). Or because I gave my fermenter a big squeeze because I love it, and then when I let go it sucked giant gobs of air into it. Except I don't do that. My fermenters are enclosed in a space that I am always sanitizing, so there in general should not be a lot of free floating brett in there that might be sucked in under the lid lip with a bunch of air if the fermenter cooled rapidly (which I don't allow to happen anyways). That amount of brett would likely be so small and so late into the fermentation that it will if anything give me gushers long after bottling, if it manages to do anything at all - but not show as a pellicle in the fermenter - and I rarely have gushers (I haven't had a gusher infection in 3+ years). Also I can have 3 fermenter side by side in that space, and just because 1 gets infected, the others do not (unless it was the same batch pitched into 2 fermenters, in which case usually both are infected (case in point the beer you mentioned, but the batch fermenting next to it didn't get any) which points back at transfer/cooling time or some other thing I did to both beers), even though Brett would potentially be blowing out into the air in that space and if getting sucked into other batches was a problem they should all end up that way.

My current process of doing what amounts to lid on until it's cooled and then transfer as rapidly as possible to fermenter and trying to never remove the fermenter covering as much as is possible (lid on hop stands vs. dry hops) has reduced my Brett infections from a typical of 4-5 or so every year down to just 1 this summer. 2 now, but that's because I intentionally re-pitched it since I wanted more. (I actually like my Brett).

If it was getting in because of the semi-open fermenting changes to my process pre-fermenter would have no effect.

My brett lives in my ductwork - in the past I um... spilled a big starter of Brett C on the floor of my kitchen and a good bit of it went down the cold air return which for god-knows-what reason happens to be directly under my counter... oops... between that and possibly the fact that my house was the old farmhouse for a big apple orchard and the put up apples in the basement for 30 years or more, and also possibly that my entire street and all the streets around are still lined with fruit trees, my house is really just Brett city. I don't know what it lives on, likely other random crap that goes down that return from the kitchen... but live on it does. One day I'm going to get one of those yeast isolation kits and try to capture all of what I have in here and try to create distinct strains if there is more then one kind. There are no other homebrewers in my hood that I am aware of, so I don't know how much is a hood problem and how much is just my own spill and/or the farmhouse, but it is what it is. I'm not sure if there is more then just Brett C, as it always tastes like Brett C... never had anything like Brett B or other strains that have a much stronger flavor, unless I actually pitched it on purpose.

In any case, when this sort of thing happens at a brewery they sometimes have to rip out all the ductwork and replace it. I can't afford to do that, and since I don't hate the stuff I just find methods to manage it, and if it does get into a batch I role with it happily. My brett isn't much of a souring agent, it's just tropical/pinapple and light hay like funk, so it kind of works in anything hoppy or not. So in that regards I'm lucky I guess.

[Kealia]

Interesting indeed as I've never had DMS issues either.

I've done a number of short boils (DME/LME) and frequently do hopstands for 30 minutes with the lid on ( )! I also "pour" the condensation off the lid back into the wort post hopstand ( )!

If anybody I've ever sent a beer to has tasted DMS speak up now.

It maybe good information in terms of "Best Practices" but that is a far cry from NEVER do this or that.