Thoughts on Open Fermentation

[Bassman2003]

Thanks for posting the video. I did not remember the fermenters that they passed on the way to the coolship!

Vale, if interaction with the atmosphere does not play a part in "open fermentations", would you say that a low profile fermenter design with an airlock right next a low profile fermenter that was open would yield the same results?

 

[Vale71]

Vale, if interaction with the atmosphere does not play a part in "open fermentations", would you say that a low profile fermenter design with an airlock right next a low profile fermenter that was open would yield the same results?

Exactly. Many traditional breweries have had to refurbish their "open fermenters" to comply with current healht and safety regulations. They've kept the same geometry but the tanks are now lined with stainless and capped, allowing CO2 to be vented to the outside and protecting the wort from falling debris. Basically the only difference to a modern conical is they cannot withstand any positive pressure and hence don't allow spunding.

 

[Bassman2003]

Can I ask how you know this? And do these breweries think the beer turns out the same as before the forced retrofit?

 

[cire]

Handrails and wire mesh would seem sufficient to comply with health and safety regulations at this brewery and forced ventilation removes excess CO2. I would have though beer would not be the only food to be made uncovered. As far as I am aware, this brewery doesn't make lager or use bottom fermenting yeast and has no conical. The picture I posted previously is of a brewery that uses a bottom fermenting yeast to make a lager in a conical, although I've not seen it, only a written hop schedule for that conical.

 

[BandonBrewingCo]

This is an interesting part of the brewery. Here is one from the next stage where they give you samples straight from the old wooden huge barrels.

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To see this christmas morning like joy on a grown man's face... god I love beer

 

[Vale71]

Can I ask how you know this? And do these breweries think the beer turns out the same as before the forced retrofit?

It was part of my training. Commercial breweries don't just think the beer stays the same, they actually test for consistency. Good breweries manage to achieve it too.

 

[Vale71]

This is an interesting part of the brewery. They keep two versions of the brewery going, old and new. The new version is modern and above ground. The old brewery is directly below and naturally cool. They still brew in the old method as a control to make sure the new brew does not wander from the taste. At this point I am sure they know if it wanders or not but it is nice to keep traditions alive. Here is one from the next stage where they give you samples straight from the old wooden huge barrels.

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There weren't as many barrels (actually just a couple) when I visited but it was high summer so I imagine turnover was at its highest level.
As for the open fermentation and the wooden casks, Urquell makes a sort of "limited edition" beer that is sold unfiltered in small wooden casks and that's only available locally for events. I had a chance to try it at an event in Munich and it tastes more like a homebrewed version of Urquell and less like the commercial version, exactly like the one I got to taste from the huge barrels when I later visited the brewery in Plzen. I guess what you saw down there was production of this limited edition beer. Again, when I visited we didn't get to see that so it's probably a seasonal or otherwise sporadic thing too. The modern brewery (which I gather you visited as well) is all shiny stainless steel now.

 

[Bassman2003]

Thanks for your reply. So much to learn about fermentation... I thought I read that open fermentation is the easiest way to harvest yeast from the top cropper's. So maybe that is why the practice hangs around instead of flavor contribution.

Sounds like we were lucky to see the beer production when we visited the brewery.

 

[Bassman2003]

To see this christmas morning like joy on a grown man's face... god I love beer

Yes, it is awesome!