3 weeks ago, I brewed an AG Witbier and PM Hefe side-by-side. Fermentation was relatively long...maybe a week or so. I've left them in the primary since then and plan on bottling this week. But here's the thing: after the Wit was done, the krausen fell as is standard. But over the past week, it's acquired this foam on top. Check it:
Samples taste fine. So, anyone seen this before?