FoodScienceBrewer
Member
There was still some airlock activity and a 1 inch Krausen layer after I put it on. I have a feeling it's gonna be fine. I'll follow up with tasting notes in a couple weeks and note if I detect any oxidation.
Open fermentation experiment
- Thread starter FoodScienceBrewer
- Start date
Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:
Not all yeasts can be used in open fermentation. Those suitable for this process produce a very thick coating and often need rousing to return yeast to the wort. Before fermentation is completed, they can be top cropped for the next brew, leaving a covering which lasts until the beer is racked.
Do you still have this?!?!?
If so... well, you know.
And post pre, during, and post results and photos, etc..
FoodScienceBrewer
Member
Just bottled it all yesterday. I wish I could've done it earlier but I was waiting on a shipment from Northern Brewer. I bought the dark star burner 2.0, a case of 22oz bottles, and caps. Lo and behold only the burner arrived with the shipment (was not notified of this). I said screw it and took the bus all the way to my local home-brew shop. Serves me right for not buying local I guess
Hey @FoodScienceBrewer, notice this thread went dead before you posted comparative results on your beer. I'm curious to know what happened!
Just to comment that I open ferment because my yeasts need any closed fermentation vessel to be at least 3 times the wort volume, while can be open fermented in a vessel of twice the volume. Even so, the yeast has to be returned to the wort to keep it within the vessel and also to maintain fermentation progress.
Such yeasts should not be allowed to drop to the bottom as primary fermentation finishes, but for they that do, the vessel needs then to be covered. It is usual to harvest such yeast by top cropping when fermentation reaches its maximum rate, leaving enough to cover the surface and when that flocculates provides a complete cover that will stay intact while the green beer is gently cooled and the active yeast clean up and drop out so the beer can be racked.
Open fermentation is not necessarily a suitable process for all yeasts.
Such yeasts should not be allowed to drop to the bottom as primary fermentation finishes, but for they that do, the vessel needs then to be covered. It is usual to harvest such yeast by top cropping when fermentation reaches its maximum rate, leaving enough to cover the surface and when that flocculates provides a complete cover that will stay intact while the green beer is gently cooled and the active yeast clean up and drop out so the beer can be racked.
Open fermentation is not necessarily a suitable process for all yeasts.
jerrylotto
Well-Known Member
IMHO, the most important thing for an open fermentation is to eliminate air movement in the fermerntation area . If you put insulation strips around a closet door so it seals well, that should be sufficient. A plexiglass window would help to manage the curiosity factor and allow you to respond to unexpected things Maybe a small greenhouse? 
That might work for the hobbyist, but in a commercial environment where it is not unusual, there can be dozen upon dozen of open fermenting vessels, each with 2 to 6 feet of wort covered by 2 or 6 feet of yeast. A brew might take 8 hours, but primary fermentation typically takes 7 days needing forced ventilation to disperse all the CO2 so produced to avoid killing any nearby workers.IMHO, the most important thing for an open fermentation is to eliminate air movement in the fermerntation area . If you put insulation strips around a closet door so it seals well, that should be sufficient. A plexiglass window would help to manage the curiosity factor and allow you to respond to unexpected things Maybe a small greenhouse?
Check out Bell's Stairway to Heaven.
jerrylotto
Well-Known Member
This is Homebrewtalk, not Commercialbeertalk!
Braccy- bravo! One of your best yet, Sir!lol, depends on if you're a supporting member and have ads turned off!
If the workers in Sam Smiths Brewery can observe their beer while it is fermenting,
have a pint and pose for a picture while standing by fermenting beer holding the side of an open fermentation vessel,
why shouldn't a homebrewer do similarly?
He could even provide a picture of an extant crust on day four when primary has finished and beer cooling gently while the yeast cleans up. This beer will be racked in 3 days time into a sealed vessel and naturally carbonate at ~50F in a week to ten days.
beersk
Well-Known Member
- Joined
- Mar 22, 2013
- Messages
- 1,732
- Reaction score
- 801
FoodScienceBrewer
Member
My apologies. I did forget to post a followup. I stole a little from the main batch before I bottled it and noticed the banana/clove flavor characteristic of a Hefeweizen. This made me very excited. When I finally got to compare the two side-by side fully carbonated I did notice a significant difference in the phenolics/esters in the open fermentation batch (higher presence of the banana and clove flavor). The difference I noticed was mainly in the smell. I do remember noticing the open fermented batch did oxidize more quickly overtime and did not remain drinkable as long as the main batch. How much longer? I couldn't say. I've been committed to taking more detailed notes in my more recent brews.
My bad, and I was there on a brew masters tour!
Very interesting! Seems like this makes logical sense from what I've heard about open fermentations before - more ester & other flavor compound production but the threat of oxidation. Thanks much for the update!
