Anyone ever have issues with oats causing sourness or off flavors?
Here is some quick background:
Been brewing with an all grain infusion mash set-up for over a year with no real issues.
Brewed what is essentially a pale ale with mostly german ingredients over the summer and added half a pound of rolled oats with 15 minutes left in the mash. Beer turned out great with a very slight yeasty/tangy flavor that we mostly enjoyed. It was not expected as we used an American Ale yeast, but we liked the taste and didn't think twice about it. We liked it so much we redid it in the fall with the same hop profile, Cry Havoc yeast and similar malt bill. Only real difference was we added half a pound of flaked oats for the whole mash.
Fast forward to last week: I took the initial beer with a few others to my local craft brewery, Metropolitan Brewing in Chicago, for a taste test. They quickly identified that tangy/yeasty flavor above as some type of infection: could not decide between lacto or wild yeast, but an infection nonetheless. In addition we tried the redo ourselves for the first time and it was extremely sour and virtually undrinkable. We have never had an infection before and even brewed a batch in between with no issues that was taste tested at Metro.
We quickly believed that the oats were the issue, but after further research I haven't found anything to verify. To the contrary I have found that the only way sour flavors are produced is some type of infection. The clean beer in-between leaves me doubting, but it is what I have found.
For both mashes we were at around 160 degrees and sparged at 170.
Thanks for the help.