Milk Stout Infected?

[rowyourboat]

Hoping for some help as had a bit of a mess on the last brew, a chocolate milk stout recipe from Malt Miller.

Initial gravity actually came up over expectation at 1.061. It went off like the clappers but seemed to stall after a few days at about 1.030. Initial mash was a bit hot so I wonder if I might have mashed some unfermentables out, plus I had 500g lactose in there which will keep it high but still seemed a too high overall. After 2 weeks I pitched another yeast and after 2 more weeks it's come down to about 1.026 and I decided to risk bottling and acept it was maybe a low attenuation/high unfermentables.

I'd been drawing hydrometer samples from the tap on my FV but when I've taken off the lid there was a bit of a film on the top of the beer:

You can see where the hydrometer pierced the film.

It tastes and smells fine and I've come this far so I've risked bottling (and left a couple of inches of beer from the top behind just in case), but was this a bad idea? I'll obviously be keeping a close eye and potentially pour them if I have to...

If it is an infection, presumably my FV needs a deep clean before the next brew. I use VWP for normal cleaning, anything else I should do in addition?

[bitter_dave]

If you’ve got 500 grams of lactose and that starting gravity 1026 sounds about right I would say. Milk stouts do have high final gravities because of the lactose and yours sounds about consistent with Graham Wheeler’s recipes. With regard to infections I would not personally assume this from the photo at this stage.

VWP is decent stuff, I used to use it exclusively for cleaning and sterilising . I still use it as a cleaner applied with a cloth for about five mins and use starsan/Chemsan as a final ‘steriliser’, but this is more about convenience.

[rowyourboat]

Thanks Dave, hopefully it'll turn out alright. I've never seen a film like that on the top of the beer but I don't make a lot of darks, don't know if that might be a factor.

Deep clean with VWP to be carried out in due course...