When you have a foaming drink, beer,soda why does the foam go down quicker when you put your finger in it?!

When you have a foaming drink, beer,soda why does the foam go down quicker when you put your finger in it?

They are correct indubitably. I will continue when

I come home tonight with a giant buzz-on.

Otay, Yes the surface tension of the bubble latttice network looses cohesion when disrupted by oil from a finger. But interestingly enough alcohol also has negatively effects beer foam stability. Existing in the beer, produced from the grist in the mash are proteins (glycoproteins), fatty acids, and hop substances . It is the natural substances in the beer that contributes to its foam instability. When the oils of the finger are localized (and not disbursed throughout the foam) it destablizes the surface network, reduces its cohesion leading to foam failure.

Beer is its on enemy as processing (mash) can negativly effect foam stability. This is true because during mashing large molecular weight proteins are degraded and fatty acids produced.

In Summary: background information of beer foam a lot of Science Stuff: (Read at your own leisure)
The behavior of beer foam can be explained by assuming that beer proteins are the major foaming agents. The main component of beer foam are high molecular weight glycoproteins. These are derieved from the malted barley and enhanced with use of unmalted cereal adjunts, barley, and wheat. The paradox for the brewer is that the same proteins desired for beer foam are also responsible for haze (turbidity). In ales, the amount of surface-active proteins present well exceeds that for reasonable head retention, but in lagers the amount is only adequate for satisfactory foam stability.
Lipids (fat = fatty acids, glycesides and phospholipids) are also surface-active material and will form a mixed surfactant system in beer in competition with the surface-active proteins for space in the surface films. If the lipid exists in discrete clusters in the surface film, the film will lose its uniformity, much of its elasticity, and will collapse rapidly.On the other hand, if the lipid is dispersed evenly throughout the film in association with the foaming agent the ensuing foam can have either better or less poorer stability.

The hop iso-alpha-acids are also concentrated into the foam. Addition of iso-alpha-acids to beer increases head retention but, in particular, the iso-alpha-acids are resopnsible are resopnsible for foam adhesion, cling or lacing. Traces of heavy metal ions (iron, cobalt, nickel, and copper) also improve the head retention of beers but only in the presence of iso-alpha-acids.
The physical properties of the film relevant to foam formation are surface tension, surface elasticity, and surface viscosity. The surface tension should be low since it is a measure of the energy required to form a new surface. The film should be elastic so that local deformations do not need to create a new surface. With an elastic film the ingress and egress in the film is relatively slow so that the surface viscosity is high. Surface viscosity is a direct measure of the adhesion between molecules in a film and it increases in the presence of iso-alpha-acids.
For a foam to be stable, once formed, some change must occur in the surface-active molecules within the film. Such changes could be brought about either by changes in the conformation of the protein ot by cross-linking of the protein with small molecules such as the iso-alpha-acids or by metal ions.
The foam stabilizer most commonly used in the brewing industry is propylene glycol alginate. The major function of such charged polysaccharides as foam stabilizers is to overcome the detrimental effects of lipids.

So it is a disruption of the foam forming agents and the actual stuctures of glycoprotein, iso-alpha-acids, metals, and stabilizing agents that result in its collapse. This can be incresed by the localized deposits of oil from a finger.