To open ferment or not to open ferment?

[Gnomebrewer]

The author says that the resulting 312 was different due to tank geometry and pressure, rather than convective motion of the wort:

I'm not saying it's right or wrong, but the problem with this kind of quote is that the author is probably only guessing in the first place, then it gets repeated as fact. It's the same with commercial brewers - they might say we did .... which gave .... result because of .... reason, when in fact they don't know what the reason was at all - they only know that the result was different when they made a process change.

 

[duncan.brown]

I'm not saying it's right or wrong, but the problem with this kind of quote is that the author is probably only guessing in the first place, then it gets repeated as fact.

I'd definitely agree with you. The scientific aspects of brewing are extremely complex with many different interacting biological, chemical, and physical processes. Most of the literature seems to be focused on increasing efficiency and not on comparison of taste. Unsurprising, given that breweries probably don't want to tell their competitors exactly why their beer tastes this way.

For an example of the challenges measuring something that was brought up earlier in this thread, take a look at Meironke, Kasch, and Sieg (2016) where they attempted to use ultrasound doppler velocimetry to measure the fluid flow in fermenters of different geometries. They took some interesting data. However, when I read their conclusion it seems, to me at least, to read "this experiment is hard and our data is not good enough yet to draw strong conclusions." Given this paper, I would be hard pressed to make a strong statement like "it's wort motion that affects flavor."

At the end of the day, the result that seems to matter to commercial brewers is some combination of profitability and consumer taste (with the coefficient of each depending on the type of brewery). I believe AB InBev gave up trying to reproduce Goose Island's core range exactly as it was produced in Chicago. I think they decided that it was only the Goose Island brewers and hard-core fans in the original market who could tell and they'd make money regardless. I suspect the average shopper looking for a wheat beer in Wegmans doesn't care.

New Glarus, Russian River, and Sierra Nevada (and others) have decided that open fermentation is important to their product being successful. Clearly they must believe that it makes a noticeable difference to the consumer to invest in open fermentation. They have not published any research (as far as I can find) on its effect on flavor, or the reasons that it does affect flavor. Whitbread did publish showing that they can make a beer indistinguishable to consumers using either Yorkshire squares of cylindroconicals. But they adjusted both the yeast and hopping to do do.

On the home brew scale, I suspect the answer is to experiment with different techniques as time permits and drink the beer you like, brewed using the methods you like. RDWHAHBBUTMYL?

 

[Bilsch]

just know it won't be LoDo..... lol

That is not necessarily true. If your yeast are healthy and you have a thick protective foam covering your beer, then what little O2 gets in will be consumed by the yeast. This is the biggest reason why the yeast from open ferments are so healthy. It's gets tricky though to protect your brew after high kreusen so it's best to transfer to the keg and spund to finish. You are right though if left open past the peak of activity, you will take a toll in oxidation.

For those not worried about oxidation can happily open ferment to final gravity.

 

[Bilsch]

I'm was scrolling down wondering when the lodo crowd would come in to burn this thread to the ground!

One of the Lodo folks was the 3rd post on this thread which I thought was pretty helpful in sharing his years of open fermenting experience with the OP.

 

[duncan.brown]

One of the Lodo folks was the 3rd post on this thread which I thought was pretty helpful with sharing his years of open fermenting experience with the OP.

I refer the honourable gentleman to the reply I gave some moments ago.

 

[Bilsch]

I refer the honourable gentleman to the reply I gave some moments ago.

I see that and thank you for your well reasoned reply.

 

[Argyll Gargoyle]

I’m speaking as a noob here, but as I understand it, lodo techniques claim to produce/preserve some flavor subtleties in particular beer varieties? And since flavor is pretty subjective, it is hard to “prove” claims like that. At least if you’re trying to write a research paper.
BTW, this thread also seems to be about techniques to give particular beers an intangible English flavor. Ok, well maybe it’s a bigger effect, and easier for others to try it for themselves?

 

[Bilsch]

I’m speaking as a noob here, but as I understand it, lodo techniques claim to produce/preserve some flavor subtleties in particular beer varieties? And since flavor is pretty subjective, it is hard to “prove” claims like that. At least if you’re trying to write a research paper.
BTW, this thread also seems to be about techniques to give particular beers an intangible English flavor. Ok, well maybe it’s a bigger effect, and easier for others to try it for themselves?

I think that is a fair assessment of the situation.

 

[day_trippr]

I think it could be applied more broadly - even generically. Preserving grain character subtleties is not really "style" dependent, after all. But it's a start

"Proof" is always an interesting aspect. I imagine chemists could easily determine comparative levels of oxidized compounds between techniques, although determining a prototypical "non-LoDO" process might be difficult for the comparison - there's everything from "close to decent" to "apocryphally bad" for potential scope

Cheers!

 

[Argyll Gargoyle]

Daytrippr,
Where does extract brewing fit on that spectrum? Should I be squeezing the LME out of the jug under water?
(Only kidding, guys!)

 

[bracconiere]

"apocryphally bad"

 

[day_trippr]

Yeah, I'm not sure of that one.
Sounded right in my head, but should have gone with "pathologically bad". No ambiguity there

Cheers! (In my defense, I have been drinking a bit )

 

[Gnomebrewer]

this thread also seems to be about techniques to give particular beers an intangible English flavor.

My first thought with open fermentation is 'hefeweizen'. But on the same track as English - looking to really push ester creation from the yeast. Check out some of the youtube clips of German hefeweizen breweries with massive shallow square vats of hefeweizen bubbling away with yeast overflowing.

 

[Beermeister32]

Back in the early 1960's when I was a kid, my Dad would ferment his beer down in the basement using a 10 gallon pickling crock. It was "semi" open, as he would cover the top with a clean cloth. The smell was fantastic and a source of intrigue for me. No airlocks, the fabric would keep away pests and allow air transfer and CO2 venting. I asked him once how the beer tasted. He said "yeasty!!!!" Dad was a funny guy..!