What happens when you’ve run one too many oceanography demos and like beer? This:

Initial observation:

Water experiments using a density tank are really fun to run, and to watch. The layering of a black and tan beer works due to the same principle (density-based layering).

Question:

Can we get a black and tan to behave like water of different densities (hot vs. cold, fresh vs. salty) in a density tank?

Expectation:

As long as the density contrast is high enough, there should be no reason beer wouldn’t behave the same way.

Equipment & Materials:

• a divided tank (ours was hand-made using a Clear Magazine Holder, spigot, and the divider was made from a plastic corrugated yard sign with the sliding bars from report covers on the edges…. but small divided beta tanks are great for two large, 19-24 oz bottles)
• 2 types of beer, ideally significantly different gravities and colors. This trial was done with 2x 64 oz growlers, for a total of 1 gallon, of beer. Growler #1 was the Park Bench Porter from Brickside Brewery and a seasonal brew from the Keweenaw Brewing Company; Good-Bye PA.
• friends to share the bounty

Procedure:

1. Make sure the tank divider is firmly in place, and resting against the bottom of the tank
2. Simultaneously pour the two beers into the sides of the different sides of the tank. The goal is to keep the pressure equalized across the divider by keeping the fluid level at the same height on each side. Otherwise, the fluid on the higher side is much more likely to leak through any gaps, or if your divider is not held by a track, the fluid pressure may even dislodge the divider!
3. Quickly and smoothly remove the divider
4. Enjoy the internal waves and the resulting beverage with fellow doers of science!

Data:

Update: Enhanced version with 8x replay.

This was the result of many trials. Some attempts failed due to lack of density contrast (it is sometimes hard to find density/gravity information for brews), failed visually due to lack of color contrast, or tasted odd due to  non-compatible flavor profiles.

Conclusion = Awesome (but please drink responsibly).