Open Fermentation and/or Different Fermenter Geometry.

[Mr & Mrs Smith]

I do wonder about the geometry. Does square make a difference, I've a feeling it does.

I would suggest only in the way of space. Because they are fairly shallow a row of square or oblong fermenters wouldn't take up as much room as round ones holding the same volume.
I like this Sierra Nevada video.

 

[MashBag]

Are we talking about open open "nothing on top" or "sheet on top" or " just no airlock"??

 

[Sneedhearn]

I found this Get 'Er Brewed tour of Harvey's Brewery interesting throughout but to stay on topic discussion of their open top fermentation method starts at 9:13...

 

[Chippy_Tea]

open top fermentation

How do they stop flies and bugs getting at it?

 

[Sneedhearn]

How do they stop flies and bugs getting at it?

The head brewer reckons that the rapidly created krausen is so thick it creates a seal over the beer...

 

[Chippy_Tea]

The head brewer reckons that the rapidly created krausen is so thick it creates a seal over the beer...

If flies lay eggs on the Krausen there will be maggots in the krausen from 24 hours on according to this -
(not trying to wind you up i am genuinely interested)

The common house fly lays eggs that resemble grains of white rice. Within 24 hours of being laid, maggots emerge from the eggs.

 

[YeastFace]

If flies lay eggs on the Krausen there will be maggots in the krausen from 24 hours on according to this -
(not trying to wind you up i am genuinely interested)

Would the CO² not suffocate them?

 

[Sneedhearn]

If flies lay eggs on the Krausen there will be maggots in the krausen from 24 hours on according to this -
(not trying to wind you up i am genuinely interested)

I'm not sure how they deal with that issue although flies do like rotting organic materials and quite high temperatures like a compost heap so maybe it's just not a suitable environment for them. The brewer did say that they do weekly analysis of the yeast for foreign micro organisms so you'd imagine they would locate something as undesirable as maggots pretty quickly.

I'm a building controls engineer so my understanding of biology is somewhat limited!

 

[Chippy_Tea]

I'm a building controls engineer so my understanding of biology is somewhat limited!

I am a wagon driver that doesn't brew beer you are way ahead of me

 

[MashBag]

The head brewer reckons that the rapidly created krausen is so thick it creates a seal over the beer...

What like a co2 blanket? (see what I did there )

 

[Sneedhearn]

What like a co2 blanket? (see what I did there )

More like a 12 tog duvet.

 

[Sadfield]

Security blanket.

 

[Sadfield]

 

[Twostage]

I would suggest only in the way of space. Because they are fairly shallow a row of square or oblong fermenters wouldn't take up as much room as round ones holding the same volume.
I like this Sierra Nevada video.

I get the space efficiency and depending on material it would also be easier to make rectangular than round but I'm thinking about the affect of the shape on how fermentation proceeds and therefore, ultimately, flavour.

Can't remember if it was the Kolsch or Altbier book I've read recently but there was a definite preference for long and low rather than narrow and tall. There was an understanding that shallow worked better for them than deep. Other breweries choose tall (enormous) cylindrical fermenters. So depth impacts, but that isn't shape.

During vigorous fermentation there are convection currents which will be influenced by shape. There may be other things going on too which are dictated by having corners .

Going to have to get one of those food serving things and do a test.

Going to watch the Sierra N. video too .

 

[Sadfield]

There's a good explanation as to why depth makes a difference in this.

https://wildflowerbeer.com/blogs/blog/process-e1-primary-fermentation-geometry

If a brewery is going shallow then rectangular makes more sense as it increases the volume for the same wort depth. Not all shallow, open fermenters are square, so perhaps shape is less impacting than depth and access to oxygen.

The main reason I went with the catering gastronorm was that it was the cheapest, shallowest stainless steel vessel.

 

[Twostage]

There's a good explanation as to why depth makes a difference in this.

https://wildflowerbeer.com/blogs/blog/process-e1-primary-fermentation-geometry

If a brewery is going shallow then rectangular makes more sense as it increases the volume for the same wort depth. Not all shallow, open fermenters are square, so perhaps shape is less impacting than depth and access to oxygen.

Good read. Low and open for flavour.

Had a quick look on Amazon for gastronorms and people use them for as cat litter trays

 

[Sadfield]

I got mine from Nisbets catering suppliers, when they had a sale on.

 

[Twostage]

I got mine from Nisbets catering suppliers, when they had a sale on.

What size/depth did you get ?

 

[Sadfield]

200mm 1/1 gn 28ltr.

The biggest is 50L. As an aside if one wanted to make a koelship for wild beer brewing, the 2/1 100mm would be good.

Any food grade plastic container or storage box is good, cheap way to experiment.

 

[MashBag]

As a test you could try some hdpe, storage boxes? Available from pound shops everywhere