Infections from brewing outdoors do happen - ask Ray Mills - he ditched a lot of beer because he was brewing under a tree in the back yard!
The corn smell may be more like cooked vegetables, if so it is likely to be caused by bacteria (Obesumbacterium or Halnia). Here is some info i extracted from my BJCP archive:
Coliform bacteria strains can also give a strong cooked-vegetable note. Additionally, DMS compounds can be formed during the kilning of green malt and during mashing. DMS is also formed by the yeast in a normal fermentation. and during slow cooling of the wort by a non-microbiological chemical reaction.
Causes DUE TO PROCESS: Poor sanitation (primary cause); not boiling the wort for at least one hour; covering the brew pot during the boil, long cooling times (overnight) before pitching; under pitching; contaminated yeast (especially packet yeast and recovered sediment); high moisture malt, over-sparging with water below 160 degrees.
REDUCTION: Good sanitation; fresh yeast culture; open, rolling boil; quick wort cooling; high pitching rates; use of 2-row English malt; proper sparging.
Overall, it may be DMS caused by slow cooling, but considering the malt used & the slow cool it sounds more like bacteria to me. Dump it then nuke your setup like has been suggested. Caustic is a good idea - wear gloves & goggles & be careful.
The corny smell sounds like a bit of DMS, which means either you made a brew with alot of pilsner malt and didn't do a 90min mash and 90min boil, or you got an infection
Mr moonshine, to respond to your DMS comments......
- As per the reply above, DMS is a possibility, but if using modern well modified malts, the chances of experiencing DMS are low as these malts have low levels of DMS precursors.
- 90 minute mashes aren't necessary - conversion can be complete in 20 minutes - an iodine test will show if conversion is complete.
- Likewise, a 90 min boil isn't necessary, but can be helpful to reduce volume and concentrate flavours.
What is written in books and web sites in the US is not always necessarily applicable here in oz. I'm not having a go at you or trolling for a response to start flamewar3 (tm), I just hate to see what could be misleading information continually appear / foreign info repeated as appropriate fact.
FWIW, here are 2 good old threads on DMS :
http://www.aussiehomebrewer.com/forum/inde...showtopic=17764
http://www.aussiehomebrewer.com/forum/inde...23742&st=20 note ///'s comment on post #27
Beers :beer:
Croz