Open vs Closed Fermentation

Reading Papazian's Joy of Home Brewing, he talks about "closed" vs "open" fermentation, and specifically how closed can be better as it removes some of the bad stuff from the kraeusen that cause headaches, etc.

When I first skimmed the section I thought that open would be where you're going for spontaneous fermentation and closed was in a bucket/carboy that's been sealed with an airlock/blow off tube, but upon reading it seems as though he defines "closed" as "carboy with blow off" and "open" as "using a bucket" (possibly with an airlock? It's been a few days since I read it). This is sort of confusing, and I guess it's "open" because there's air in the bucket (dear Liza, dear Liza) -- but that gets replaced with CO2, doesn't it? -- instead of being filled to the brim with the wort (hence the need for a blow off). I think there may have been something about how a 6.5 carboy is also open (for the same reasons), but maybe now I'm just making stuff up.

Anyway, is this right? Did I get some of the stuff wrong? Is Papazian sort of over-exaggerating? He's also said in a few places that start to finish, beer should take 4 weeks, which seems to go against what most people -- pro- and anti-secondary alike -- have said on here.

Also, is the headache thing something I have to worry about? My friends are BMC folks, and while they liked the microbrew hefe and kolsch I gave them last time they were over I don't want to give them a reason to say "...yeah, but I'll stick with storebought." I want them to either buy their own equipment or start subcontracting out to me once they taste my brew

i have always read that open fermentation = bucket with no lid...rather a cloth over the top to keep large stuff from falling in.
closed = any sealed w/ airlock fermenting vessel.

this is the first time i've seen it reference nothing but head space. technically a blow off tube is just a large airlock, since the end goes into a bucket of santized solution that's big enough to catch any overflow from a vigorous fermentation.

The headache thing is more about fusel alcohols... which is temperature and yeast related...not open vs. closed.

Sigafoos said:

Reading Papazian's Joy of Home Brewing, he talks about "closed" vs "open" fermentation, and specifically how closed can be better as it removes some of the bad stuff from the kraeusen that cause headaches, etc.

When I first skimmed the section I thought that open would be where you're going for spontaneous fermentation and closed was in a bucket/carboy that's been sealed with an airlock/blow off tube, but upon reading it seems as though he defines "closed" as "carboy with blow off" and "open" as "using a bucket" (possibly with an airlock? It's been a few days since I read it). This is sort of confusing, and I guess it's "open" because there's air in the bucket (dear Liza, dear Liza) -- but that gets replaced with CO2, doesn't it? -- instead of being filled to the brim with the wort (hence the need for a blow off). I think there may have been something about how a 6.5 carboy is also open (for the same reasons), but maybe now I'm just making stuff up.

Anyway, is this right? Did I get some of the stuff wrong? Is Papazian sort of over-exaggerating?

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I think you are right. I've read that section a few times and I also think that he uses the term "closed" to refer to any system with a blow-off tube to remove the kraeusen, and "open" to mean any system that allows it to sink back into the beer.

Sigafoos said:

He's also said in a few places that start to finish, beer should take 4 weeks, which seems to go against what most people -- pro- and anti-secondary alike -- have said on here.

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Well, I think some beers probably are finished in 4 weeks. In the first chapter of his book (http://www.howtobrew.com/section1/index.html), John Palmer demonstrates an extract brew that he bottles after two weeks and is carbonated and ready to drink after another 2 weeks. Personally, I think this is rushing the beer, but it can be done. Most beers benefit from longer aging both before and after bottling.

Sigafoos said:

Also, is the headache thing something I have to worry about? My friends are BMC folks, and while they liked the microbrew hefe and kolsch I gave them last time they were over I don't want to give them a reason to say "...yeah, but I'll stick with storebought." I want them to either buy their own equipment or start subcontracting out to me once they taste my brew

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No, I don't think the headache thing is something you need to worry about. I've drunk (drank? drinked?) lots of homebrews and I almost never get a headache from it.

Now that I think about it, my wheat may be done in 4 weeks (primary for 2, bottling this weekend and will taste one a week), but I think that saying all of them will be is misleading.

I was just worried that since my primary is an ale pail, the results would be good but not great. Thanks for clearing that up for me, and also for letting me know I'm not crazy with my interpretation

I think that sometimes, too much emphasis is placed on "airtight" and "keeping out the nasties."

North Peak Brewery in Traverse City Michigan has large cubical fermenters that hold ten barrels each, and they have NO LID. They are completely open, often letting the krausen flow right out onto the floor. Customers freak out!

Their beer is exceptional!