I'm planning to brew the Delirium Tremens clone which was discussed in a long thread on the Northern Brewers forums. The recipe is simple enough, but my trouble is with my yeast starter. I cultured up a starter from a bottle of DT a couple weeks ago, and now I want to know if it is safe to put in my beer, because it smells a little wierd. Here's the story.
I dumped the bottom 1/3 of a bottle of DT into a 1L starter, about 1.040 gravity. Miraculously, within two days it was clearly fermenting and a couple days after that a yeast cake had formed at the bottom. I decanted and replaced the liter with another liter of identical starter. The fermented starter tasted basically like under-attenuated unhopped DT, just like it should - tasty. A couple days later, it was finished and I replaced it with some fresh starter. This time the fermented stuff tasted really delicious, like a quality unhopped light Belgian. I tested the FG and it was 1.005 or something.
So I left the new starter fermenting in my room one day, and after coming back in the evening I realized I had left the heater on very warm all day in the closed room. The temperature was at least in the high 90s. The yeast was bubbling away. A couple days later, I decant and replace the yeast, and there is a problem.
Fermentation is complete, but the starter has a sort of funky flavor that is really hard to describe. It's not unpleasant, it's just kind of like... tuna fish. Or sort of like sweat. Or like whole grain crackers. Kind of a "hairy" smell. More than anything it's like the smell of a room where someone is eating tuna from the can. Or, pardon the expression, of your own piss when you have drunken a lot of coffee a couple hours before.
I decanted it and drank some (good, except for the off flavor) and put in fresh wort. A couple days later, the smell is the same, and the fermentation has finished.
This is my theory: that hot day killed a certain population of the DT yeast and promoted the wild growth of some other segment of the population, the one responsible for that odd taste/smell. I don't think there's an infection.
Should I throw this starter out? I hate to do that, because it's like 2 weeks of growth and almost 400 ml of pure yeast.