Is this mold?

[amberale]

Is this mold?

 

[ancientmariner52]

Looks to me like yeast and hop debris from an enthusiastic fermentation. Keep a watch on it, if it is mold, it will grow. I think you are safe, though.

 

[dsaavedra]

Definitely looks like yeast. It even looks like you use dry yeast and sprinkled it directly into the fermenter. Some granules got stuck to the neck of your carboy and are "rehydrating" up there.

 

[Bamos6928]

Looks like yeast that didn't make it all the way into the wort.

 

[Lefou]

The neck of the carboy was coated with wort and the yeast decided to grow right where it stuck.

Totally normal.

 

[mmb]

It looks like you have a yeast infection.

Congrats, you've made beer!

 

[mr_stout]

Yeast.

 

[FVillatoro]

Looks like yeast that didn't make it all the way into the wort.

I second this.