Open fermentation & Why ?

[cire]

Open fermentation in Britain takes 2 to 3 days, initially with rousing to return the yeast to the wort, else fermentation would be slow with a small portion of the yeast active. The yeast is cropped for future pitching, after which the beer is cooled as fermentation nears completion.

The process uses a particular type of yeast, one that rises and flocculates on the top of the wort. It won't work in tall narrow vessels that aren't wide enough to accommodate the yeast so produced. It is not possible for other types of yeast to work in the same manner.

The original yeast that Harvey's obtained from John Smith's in 1957, as seen in the earlier video, can be obtained from Brewlab in UK, Their code for that yeast is 48.

 

[hotbeer]

I'm sure they ferment really quickly, something like 3 or 4 days but can't remember what I was told now

I'm sure they do ferment in 3 or 4 days.

My point is that soon after fermentation is completed and before the kraeusen foam disappears, the beer is moved to a closed system much like what my FV becomes after my beer has fermented in that same 3 to 4 days.

Open fermentation isn't as much of a risk if yeast is going to be pitched. A proper pitch of healthy yeast should quickly out pace any contamination of wild yeasts and bacteria. But after the ferment is over and the foam starts to disappear, then contamination will start to be an issue.

Which is why most of the few breweries still doing open fermenting to my current knowledge move it to a bright tank. They don't leave it in that open ferment vat till the beer is clean and clear and ready for bottling. And that to me doesn't seem any different than what my FV becomes for the 10 days to 6 weeks after the beer in it finished fermenting.

It is probably only those that want to do open fermentation depending on wild yeast to make a good beer that are more of a gamble and more dependent on environmental and sanitary conditions in their particular area.

 

[cire]

I'm sure they do ferment in 3 or 4 days.

My point is that soon after fermentation is completed and before the kraeusen foam disappears, the beer is moved to a closed system much like what my FV becomes after my beer has fermented in that same 3 to 4 days.

Open fermentation isn't as much of a risk if yeast is going to be pitched. A proper pitch of healthy yeast should quickly out pace any contamination of wild yeasts and bacteria. But after the ferment is over and the foam starts to disappear, then contamination will start to be an issue.

Which is why most of the few breweries still doing open fermenting to my current knowledge move it to a bright tank. They don't leave it in that open ferment vat till the beer is clean and clear and ready for bottling. And that to me doesn't seem any different than what my FV becomes for the 10 days to 6 weeks after the beer in it finished fermenting.

It is probably only those that want to do open fermentation depending on wild yeast to make a good beer that are more of a gamble and more dependent on environmental and sanitary conditions in their particular area.

Most yeasts have krausen that collapse as fermentation ceases, so are unsuitable for open fermentation for all the reasons feared. If your yeast is like those below, then it could be suitable for open fermentation.

As above, suitable yeasts sit on top of the wort unless forcibly returned. Left unroused the wort would eventually fully ferment, but with only a small percentage active it would take a week or more rather than a couple of days. So the wort is roused for a few minutes every hour or so until fermentation peaks, when the surplus is harvested, or in the case of Yorkshire Squares, retained in its upper section. The wort is then cooled, the wort clears and the crust stays firmly on top.

Above is my open fermentation with a similar yeast after harvesting on day 3. The yeast reached the top of the vessel and a covering left for protection when harvested.

The picture below was taken 4 days later, as the beer was racked and the crust only then began to break up. If the beer was chilled or left for another 2 weeks, then potentially the yeast could sink, but those aren't part of open fermentation procedure.

 

[jambop]

Most yeasts have krausen that collapse as fermentation ceases, so are unsuitable for open fermentation for all the reasons feared. If your yeast is like those below, then it could be suitable for open fermentation.

View attachment 817413

As above, suitable yeasts sit on top of the wort unless forcibly returned. Left unroused the wort would eventually fully ferment, but with only a small percentage active it would take a week or more rather than a couple of days. So the wort is roused for a few minutes every hour or so until fermentation peaks, when the surplus is harvested, or in the case of Yorkshire Squares, retained in its upper section. The wort is then cooled, the wort clears and the crust stays firmly on top.

View attachment 817415

Above is my open fermentation with a similar yeast after harvesting on day 3. The yeast reached the top of the vessel and a covering left for protection when harvested.

The picture below was taken 4 days later, as the beer was racked and the crust only then began to break up. If the beer was chilled or left for another 2 weeks, then potentially the yeast could sink, but those aren't part of open fermentation procedure.

View attachment 817414

There is no substitute for knowing what you are talking about

 

[gewehr43sniper]

sanitized open top FV + ale yeast starter, dump chilled beer into, toss in yeast, yeast will quickly take over and push out any bad bacterias in the air.

 

[passedpawn]

My friends and I were at an altstadt (Dusseldorf) brewery and asked for a brewer. I wanted to take some altbier yeast home. Brewer was drunk and we had a great time down in the brewery under the restaurant.
Open fermentors, right next to the bright tanks. I put a bunch more here for anyone curious - lots more photos and video here.

 

[Anti-Hoppist]

Yep, homebrewers on the Continent and UK do this. But you better split the 5g up in different small batches, and use them as starters after asessing their qualities when fermentation starts.

And only after summer, Sep-Oct.

Why after summer? More quality bacteria?

 

[chthon]

Why after summer? More quality bacteria?

I think it got something to do with getting colder. But e.g. grapes also only get natural yeast on their skins after summer.

 

[Anti-Hoppist]

I think it got something to do with getting colder. But e.g. grapes also only get natural yeast on their skins after summer.

I see. I have a friend with some some peach trees, maybe one day I could try to ask to let me "rest" my wort near his trees and see if some magic happens.

 

[mac_1103]

Or maybe just pick a ripe peach?

 

[Anti-Hoppist]

Would be too little magical to be fun...

 

[mac_1103]

OTOH it might actually work...

 

[whattabrau]

I see. I have a friend with some some peach trees, maybe one day I could try to ask to let me "rest" my wort near his trees and see if some magic happens.

There are at least some claims that suitable yeast/bacteria for spontaneous fermentation hang around the building as much as the raw material, with raw material [obviously] being more applicable to wine than beer. I doubt that peach trees are guaranteed to be any better than no peach trees. However, since it's a good idea to have multiple spontaneous fermentation batches ongoing for blending purposes -- some of them end up tasting like battery acid and you need to take the acidity down a few orders of magnitude -- you might as well throw a "peach" brew in there.

 

[keggert]

Some of the things that are learned at the beginning stages is due to the various mistakes that will be made at the start. One of the biggest is not pitching enough yeast. How many times have you pitched yeast and didn't see active fermentation for 24+ hours. Those breweries who are doing open fermentation see active fermentation easily by hour 12. The brewery I visited that did open fermentation doesn't allow visitors in the fermentation room during the process, must keep everything clean!!

 

[Lefou]

So what about making 5 gallons of wort and leaving it in the backyard without pitching to see what happens?

I could never trust that method - or the two dogs who'd sniff it out in seconds.

 

[Lefou]

Brew life in 2015 B.D. (before dog) was much easier. I'd leave a 3 or 6 gallon glass fermenter in the kitchen. Not anymore.
I've always been fascinated with the idea of an open fermentation experiment, but with a 60lb Husky in the house who has a kelpie-Husky "mini me" following him around it would be a potential disaster waiting to happen. A potential poisoning from hopped wort isn't something we want.

 

[user 338926]

If you have one minute here's a great time lapse. There's actually rather a lot to glean from this video If you think about what you're seeing.

 

[user 338926]

Lindemans Framboise Lambic is made that way. The only word I can use to describe it is, transcendent. But you might want to mow the neighbor's grass a few extra times to earn some expendable cash in order to buy a case.

 

[odie]

here is my attempt at open fermentation...hefe in an open keg. I placed a paint strainer over it with a rubber band to keep any bugs out...

 

[odie]

well...it was a mess. I removed the mesh bag to seal the keg...crap dried everywhere. I cleaned it as best I could and was able to get the lid to seal. Took it outside and washed and scrubbed best I could after that. Will just leave it alone now and see what it tastes like when it's done.

 

[Beekeeper]

well...it was a mess.

fermentation vessels would need to be 3 to 4 times the wort volume to keep the yeast within bounds.

Oops.

 

[tracer bullet]

I've always wondered for exactly how long open fermentation remained open? Until packaging, or perhaps more like... I'll pick a random number but let's say 4 days. When is the beer moved out of the open fermentation space and what's next for it?

 

[Bassman2003]

To the OP on contamination or bacteria - One thing to remember is that once the yeast get going they drop the pH into the 4s. This pretty much stops anything else from living that could harm the beer. pH 4.6 is the safety number to be below even for Botulism. That underlying behavior makes open fermentation work. As stated, it is more important to have a quick start to your fermentation as the pH will still be in the 5's before the yeast activity and the wort is 'open for business' so to speak.