Yeast / mead question

[Laripu]

I'm making another batch of mead and using a yeast from Lalvin called Opale, which is supposed be for white wines and enhances citrus flavours.

I rehydrated as per instructions, and pitched the yeast yesterday. It's in a glass carboy, and therefore I can see what's happening.

This morning, then was a nice little head on the must, but only occasional bubbles in the airlock.

Now, just a few hours later, the airlock is actively bubbling, but the surface of the honey shows no sign of fermentation. The head has collapsed back into the must.

Now I know honey has very little protein with which to form a head, so that's probably normal, but I've never seen this quick a collapse. I'm not worried about the fermentation, because lots of CO2 is being formed.

Has anyone else seen this before? Or used this yeast before?

[oldbloke]

I think I recall my meads not having much crust. With melomels you get the fruit pulp being held at the top by the rising gas.

[awalker]

I use lalvin not sure which one. Very little surface foam or activity.

But you can hear it at work thats for sure

[Laripu]

I use lalvin not sure which one. Very little surface foam or activity.

But you can hear it at work thats for sure

And I see it in the airlock too. Five days later, still going strong. I expect 15 to 20 days of primary ferment.