Oils from your face will make the foam from beer subside faster?

Question

I've seen people wipe the area around their nose then touch the foam/head on their beer after a bad pour.

Does this make the foam go away faster?

Answer 1

Inserting your finger into any foam will disrupt the bubbles and cause them to come into contact with a separate surface than just the surrounding bubbles. This agitation serves to break bubbles. The addition of oils actually has a basis in fact because of the chemical nature of beer bubbles. This webpage explains

Each molecule of these grain proteins have two ends with different chemical properties; one end is attracted to water, while the other is repelled by water.

As gas bubbles emerge from the beer, nearby protein molecules rearrange themselves with their water-avoiding ends sticking into the gas bubble, away from the liquid. At the same time, the water-loving ends stick out into the beer.

Each bubble of gas is surrounded by a layer of protein molecules which are all lined up in the same direction, strengthening the surface of the bubble.

Oils from your skin stop the foam from overflowing by breaking up the protein layer surrounding each gas bubble. As the water-avoiding ends of the proteins are more strongly attracted to the oil than to the gas they pull out the bubble, weaken its surface, and cause it to pop.

This web page provides an experimental set up you can perform on beer foam. One of the conclusions/discussions says

Soap, detergent, grease and wax residues will kill foam formation and retention actually attack the foam on a head of beer. Fatty substances are attached to the surface on the bubbles. The surface tension on the bubbles is lowered. They will burst. As a result the foamy head disappears, causing the beer to look and taste "flat".

While not totally relevant, it is none the less interesting, scientists have performed mathematical studies of beer bubbles (and who wouldn't want to assist in that research?). As one of the most common beverages, we do spend a lot of time studying it. A subject I endorse.