Uncarbonated Head Retention Vs Carbonated Head Retention

[BeerSwiller]

Hi All,

I am still trying to work out why my head retention is poor, I have one possibility which would be adding all the hot break into the fermenter??
My last brew I actually removed most/all hot break when syphoning from the no-chill cube to the fermenter so i will see if this makes a difference.

Anyway, with my beer being straight from the filter into the keg uncarbonated, I can get a syringe and entice a foam head onto a sample of uncarbonated beer and will sit for ages without dissipating, but when carbonated, it forms well but then dissipates quickly....

Cant work this out, any ideas? Please.. :unsure:

 

[Bribie G]

That's why you get such a good head on Guinness. Nitrogen is used to pressurise and serve Guinness in a ratio of 80% nitro to 20% CO2. Which maybe by coincidence is the ratio of the N to O in the head you induced in your flat beer. The head is formed by bubbles which consist of the protein-carbohydrate mix that exerts surface tension to trap the gas inside the bubble. Because nitrogen molecues (N-N) are "smoother" they can't escape whereas CO2 molecules O-C-O are more "spiky" if you like, as well as forming inherently larger than nitrogen bubbles as they nucleate out of carbonated beer, and burst the bubbles and dissipate more quickly as the protein-carbohydrate mix can't contain the gas as easily as Nitrogen.

That's according to Guinness who invented nitro kegging in the 1950s with research by Micheal Ash, a chemist there.

Edit: what you are doing with your syringe is basically what the "sparkler" on a British Hand Pump does in Places like Cardiff or Leeds where they love a creamy head on their real ale, by injecting a heap of good old air (80% Nitrogen) into the beer, giving it almost Guinness like creaminess. Ah for a pint of brains SA or Jennings etc right now :icon_drool2:

 

[BeerSwiller]

That's why you get such a good head on Guinness. Nitrogen is used to pressurise and serve Guinness in a ratio of 80% nitro to 20% CO2. Which maybe by coincidence is the ratio of the N to O in the head you induced in your flat beer. The head is formed by bubbles which consist of the protein-carbohydrate mix that exerts surface tension to trap the gas inside the bubble. Because nitrogen molecues (N-N) are "smoother" they can't escape whereas CO2 molecules O-C-O are more "spiky" if you like, as well as forming inherently larger than nitrogen bubbles as they nucleate out of carbonated beer, and burst the bubbles and dissipate more quickly as the protein-carbohydrate mix can't contain the gas as easily as Nitrogen.

That's according to Guinness who invented nitro kegging in the 1950s with research by Micheal Ash, a chemist there.

Edit: what you are doing with your syringe is basically what the "sparkler" on a British Hand Pump does in Places like Cardiff or Leeds where they love a creamy head on their real ale, by injecting a heap of good old air (80% Nitrogen) into the beer, giving it almost Guinness like creaminess. Ah for a pint of brains SA or Jennings etc right now :icon_drool2:

View attachment 46628

Hmmm, that does make sense since air is something like 78% nitrogen...

Apart from that, Is having hot break in the fermenter detrimental to head retention? Have read mixed opinions about the topic.

EDIT: Thanks for your help by the way

 

[tavas]

Hmmm, that does make sense since air is something like 78% nitrogen...

Apart from that, Is having hot break in the fermenter detrimental to head retention? Have read mixed opinions about the topic.

EDIT: Thanks for your help by the way

It was in my case. Beer flatter than a 10 yo's chest. Tasted awful too.

 

[kymba]

probly better to wait til they are 18

It was in my case. Beer flatter than a 10 yo's chest. Tasted awful too.

 

[Bribie G]

Even better when they are 30.

Yes, hot break is a no no - I get little or no HB into the cube because I use a good floccer in the kettle, cover it well and let everything settle out for half an hour, and collect the first runnings out of the urn tap in a sanitised schott jar until the wort starts running crystal clear. Instead of my former 23L Willow Cubes, I'm now using 21L cubes (AKA the FWK cube style from Craftbrewer) and get a cube of clear wort. Then as it starts to run a bit cloudy again I collect as much of the end runnings as possible in more schott jars (actually V8 1.5L glass bottles are awesome as well but use clingwrap as the metal lids are suss). Next day there is heaps of clear wort extra to be gleaned out of the jars and I use that for a post-cube hop boil.

If you look at the pic carefull you'll see:

clear wort = good
a layer of jellyfish which is cold break = neutral, no probs - chuck it in
a small layer of biscuit coloured stuff right at the bottom which is hot break = bad - discard



Ve hav vays.

 

[ben_harvey]

It may also have something to do wih the size of the molecules in addition to their shape. I've heard about people butting N2 in their car tyres because it lasts longer (yes I'm also aware that air is ~70% N), and I think N2 is larger than the other major components of air (mainly O2), but I'm not sure.

This is also why helium balloons go flat really quick if you don't use the special thicker ones (i.e. put He into a normal balloon and it will go down pretty quick, like within a day). The little molecules just go straight through the tiny gaps in the balloon. It's plausible that it works the same way with beer bubbles.

As an extension to that, if you replace CO2 with a larger molecule you may find that the bubbles last even longer. A quick look at the (2004) prices for the noble gases indicates that there may be a limit to what you could use, financially speaking.

Too far OT?

 

[Bribie G]

Argon should know

 

[BeerSwiller]

With my last batch I siphoned a little of the hot break into the cube but then drained only clear wort off the top via the tap and left most/all break material in the cube.....
This should be an ok method to use?? :unsure:

Even better when they are 30.

Yes, hot break is a no no - I get little or no HB into the cube because I use a good floccer in the kettle, cover it well and let everything settle out for half an hour, and collect the first runnings out of the urn tap in a sanitised schott jar until the wort starts running crystal clear. Instead of my former 23L Willow Cubes, I'm now using 21L cubes (AKA the FWK cube style from Craftbrewer) and get a cube of clear wort. Then as it starts to run a bit cloudy again I collect as much of the end runnings as possible in more schott jars (actually V8 1.5L glass bottles are awesome as well but use clingwrap as the metal lids are suss). Next day there is heaps of clear wort extra to be gleaned out of the jars and I use that for a post-cube hop boil.

If you look at the pic carefull you'll see:

clear wort = good
a layer of jellyfish which is cold break = neutral, no probs - chuck it in
a small layer of biscuit coloured stuff right at the bottom which is hot break = bad - discard

View attachment 46634

Ve hav vays.