Souring Guinness

[Killercal]

Hey I was looking at making a clone on here and one step is to sour 24oz of Guinness on the counter for 5 days. Now I put this on the counter 10 days ago and noticed a white film on top of it. Should I throw this out or can I still boil this and add it to the pot or will this infect my beer?

Thanks

 

[Hammy71]

When I did my version of the is clone the Guinness had no film on top...course it was only 4 days old, not 10. Is it mold? If you suspect it is....chuck it. I don't think it will infect your beer (since it's boiled for about 30 minutes), but not sure if the taste will be the same.

 

[Killercal]

yeah, it could be mold, I think I'll just re-do this step.