[Robert]

^^^^
Thought some more about this, with reference to the latte idea.  Think cappuccino.   Pretty sure milk is denser than coffee, but when frothed up it floats.  Nitro saturation in Guinness is high enough that it's breaking  out to make an analogous froth on top of the other beer, FG notwithstanding. Hence the sinking of the off-brands?

[Phil_M]

But the nitrogen comes out of solution almost immediately, it doesn't stay in the beer.

With coffee, you also have varying temperatures that come into play.

I guess we need to experiment. I just finished my last can of Guinness last weekend, so I've been needing to replenish my supply. Might pick up another stout or porter and see what happens.

I'll report my findings.

[Robert]

^^^^
Science!!!  Look forward to your report.

[scrap iron]

I have seen a devise that sits on top of the glass to pour the stout onto the bitter. It looks like a turtle, and I found this, https://www.uncommongoods.com/product/beer-layering-tool. Looks like a good Christmas gift.    I found the turtle at morebeer,https://www.morebeer.com/products/lagerhead-black-tan-turtle.

[Phil_M]

I made a similar device out of an old spoon, a hammer, bench vise, and angle grinder. Cost to me? Free.

[Robert]

But the nitrogen comes out of solution almost immediately, it doesn't stay in the beer.

With coffee, you also have varying temperatures that come into play.

I guess we need to experiment. I just finished my last can of Guinness last weekend, so I've been needing to replenish my supply. Might pick up another stout or porter and see what happens.

I'll report my findings.

I referenced this in reply #6, found a reference.  This may provide some insight into the fluid dynamics involved.  Or just make you want a coffee.

How Layers in a Latte Form https://nyti.ms/2l5KKWo

[Phil_M]

But the nitrogen comes out of solution almost immediately, it doesn't stay in the beer.

With coffee, you also have varying temperatures that come into play.

I guess we need to experiment. I just finished my last can of Guinness last weekend, so I've been needing to replenish my supply. Might pick up another stout or porter and see what happens.

I'll report my findings.

I referenced this in reply #6, found a reference.  This may provide some insight into the fluid dynamics involved.  Or just make you want a coffee.

How Layers in a Latte Form https://nyti.ms/2l5KKWo

As a full-time senior technician/part time engineering student, the implications of that article made my head hurt.

On a related note: Sam Smith's Oatmeal Stout and Yuengling Lager did not a layered black and tan make. The stout was colder than the lager though. Will try again in reverse order tomorrow to see if anything changes.

[Robert]

See, I thought maybe you'd get the science with less head-hurting than I experience.  I'm just not sure temperature or density is working the way we assume, and that makes it look more like ... well yeah I'm  confused. Cool though. Keep the updates coming!

[el_capitan]

 That device is called a brolly.

Sent from my SM-J327V using Tapatalk

[Phil_M]

So, still testing, but I'm probably going to have to eat crow on this one: appears that it IS the reduced density of the Guinness from the nitrogen bubbles that allows it to float. So far, I've only been able to replicate the two beer "split" with nitro beer, Guinness Draught and Murphy's.

Really curious what a hand pump and a sparkler would do for this...

[Robert]

Thanks for reporting! Very interesting to have some experimental insight.  Just a shame you had to sully a perfectly good Sam's Oatmeal along the way!

[Phil_M]

Thanks for reporting! Very interesting to have some experimental insight.  Just a shame you had to sully a perfectly good Sam's Oatmeal along the way!

Actually that proved to be one of the better combinations I've tried. The issue with the regular Yuengling Black and Tan for me is that it's a mix of their Porter and "Premium Beer", which is basically a typical American "meh" pilsner. I find their Lager to be an much better choice, even in the Sam Smith's you could pick out it's character. Most light lagers just tend to get lost in a stout or porter.

[Robert]

Thanks for reporting! Very interesting to have some experimental insight.  Just a shame you had to sully a perfectly good Sam's Oatmeal along the way!

Actually that proved to be one of the better combinations I've tried. The issue with the regular Yuengling Black and Tan for me is that it's a mix of their Porter and "Premium Beer", which is basically a typical American "meh" pilsner. I find their Lager to be an much better choice, even in the Sam Smith's you could pick out it's character. Most light lagers just tend to get lost in a stout or porter.

I have no problem at all with the Yuenglings.  Just hard to imagine improving on anything Sam Smith, especially their dark beers!  Hey, if my original assumption is in fact correct, that nitro makes the separation possible, then a whole new category opens up: some conventional dark beer on the bottom and a nitro pale on top...wonder what a good combination would be?

[jeffy]

Thanks for reporting! Very interesting to have some experimental insight.  Just a shame you had to sully a perfectly good Sam's Oatmeal along the way!

Actually that proved to be one of the better combinations I've tried. The issue with the regular Yuengling Black and Tan for me is that it's a mix of their Porter and "Premium Beer", which is basically a typical American "meh" pilsner. I find their Lager to be an much better choice, even in the Sam Smith's you could pick out it's character. Most light lagers just tend to get lost in a stout or porter.

This is correct about the Yuengling Black and Tan.  It is 68% Lager and 32% Porter, per the retired Tampa brewmaster.

[Phil_M]

I have no problem at all with the Yuenglings.  Just hard to imagine improving on anything Sam Smith, especially their dark beers!  Hey, if my original assumption is in fact correct, that nitro makes the separation possible, then a whole new category opens up: some conventional dark beer on the bottom and a nitro pale on top...wonder what a good combination would be?

That's what I'm wondering. My wife enjoys the Guinness nitro IPA, and another good combination we discovered in this testing was stout and IPA. Should be a good combo, though Guinness has more a British IPA than an American Craft one. (Also not a problem.)