Flaked Corn, Cream Ale Issue

[jmyers04]

That a fair amount of time for an immersion chiller. One thing I’ve gotten on to doing is using the hose to chill down to ~150, then switching over to a pond pump inside an ice water filled cooler to drop it the rest of the way. Works well and I can usually chill down to 65-68 in 18-20 minutes. Btw, I live in California where the ground water is frequently 70+ degrees

So is this lengthy cool down period the reason for possible DMS? How do you get the “cold break” they speak of

 

[NGD]

So is this lengthy cool down period the reason for possible DMS? How do you get the “cold break” they speak of

I can’t say for certain this is your issue. I’d refer to one of the more experienced brewers on here. This quote from Palmers “How to brew” would suggest that may be the case. However if your the only one tasting it then you may be more sensitive to those compounds.I have a similar issue with houses that are plumbed with pex.

DMS is continuously produced in the wort while it is hot and is usually removed by vaporization during the boil. If the wort is cooled slowly these compounds will not be removed from the wort and will dissolve back in. Thus it is important to not completely cover the brewpot during the boil or allow condensate to drip back into the pot from the lid. The wort should also be cooled quickly after the boil, either by immersing in an ice bath or using a wort chiller.

 

[mredge73]

30 minute isn't all that long, most of mine take about that long to cool to pitch temp.
I use pilsner as my base grain and do not get DMS flavors. Boil for 90min without a lid and cool in under 30min and you should be fine.

The only other thing that I can think of is grain oxidation, being that both grains came from the same store.
Stale cardboard like taste could be perceived as corny?

If you are hyper sensitive to these compounds you should taste these in commercial beers too.
I am out of suggestions, good luck finding your issue.