First all grain ferment...mold on the top...

[Orpheus123]

So I'm doing an all grain ferment. Noticed that it suddenly (last 2 days or so, started ferment last weekend, so about a week and a half ago) has white bubbles on the top. I've never fermented on grain, and I've never seen mold grow on my mash ferment. SO...is it OK? Do I just skim that crap off? It's still fermenting, I can see it bubbling. This is not an airtight container, so there's that as well.

What say you?

[Orpheus123]

Here is what it looks like

[Bolverk]

This is likely a secondary lactobacillus ferment (looks like lacto in the picture). Yes skim it off and run it, but do it soon otherwise you'll have too much lactic acid and it might be a bit off tasting. A little bit of lactic acid can be a good thing, it adds mouth feel and esters.

[Orpheus123]

Thank you! Strip run should be this Saturday. Thanks again, I admit, it freaked me out a bit...

[Bolverk]

Most distilleries that let a secondary fermentation take place usually try to run in in 24-48 hours after the primary is complete because that say it gets too sour after that... the only way I know how to kill off a fermentation is potassium sorbate but I've not heard of anyone doing that with whiskey. I'm sure someone will comment here shortly with more info

[NormandieStill]

Most distilleries that let a secondary fermentation take place usually try to run in in 24-48 hours after the primary is complete because that say it gets too sour after that... the only way I know how to kill off a fermentation is potassium sorbate but I've not heard of anyone doing that with whiskey. I'm sure someone will comment here shortly with more info

If the fermentation is already going the potassium sorbate won't do a lot. It prevents yeast (and possibly some bacteria, not sure of the mechanism) from multiplying but it won't kill any that are already active. For that you need potassium metabisulphate and you really don't want to put that into a wash if you can help it.

[Demy]

This happens when the grain on the surface are not mixed. Be sure to soak the grains on the surface at least once a day in the future.

[Bolverk]

If the fermentation is already going the potassium sorbate won't do a lot. It prevents yeast (and possibly some bacteria, not sure of the mechanism) from multiplying but it won't kill any that are already active. For that you need potassium metabisulphate and you really don't want to put that into a wash if you can help it.

Good to know, thanks Normandie

[NormandieStill]

If the fermentation is already going the potassium sorbate won't do a lot. It prevents yeast (and possibly some bacteria, not sure of the mechanism) from multiplying but it won't kill any that are already active. For that you need potassium metabisulphate and you really don't want to put that into a wash if you can help it.

Good to know, thanks Normandie

No problem. It is the fruit of experience which stained the ceiling in our dining room.

I originally stored my bottled wines in my office which is directly above and the floorboards of which are the ceiling of the room below. One day, my then 5 year old daughter announced to my wife that it was raining inside. She laughed, as you do when kids says daft stuff like that and dismissed it. The following evening she said the same thing and pointed up at the large pink stain which was, effectively, dripping! Turned out that the peach wine that I had backsweetened and bottled had continued to ferment and pushed out the corks. One bottle was about a 1/3 empty and another had almost lost the cork. I very nearly lost my fermenting privileges that day, and my hedegrow wine collection had to move into the crawlspace under the house!

[The Baker]

Happened to my ginger beer when I was a kid.

Geoff