Why did my hot pepper oil get moldy? While following the advice in this answer I placed two ripe Bhut Jolokia peppers in a fresh bottle of olive oil, and put it on the shelf to sit for a month so the heat from the peppers would infuse the oil.

However, one of the peppers became covered with white mold.

The two peppers were put in at different times, as they ripened, since I only got half a dozen peppers from the plant, and they all ripened at different times.

The first pepper went into what had been an unopened bottle of olive oil, after I cut out a small blemish, and removed the stem and top of the pepper.  It floated at the top of the oil for a few days, perhaps as long as a week, before sinking to the bottom of the bottle.

The second pepper was added about 1.5-2 weeks later, and was more intact (there was no blemish, so I only removed the top to remove the stem and expose the seeds).  That pepper floated on the surface as well, but about 1.5-2 weeks later, I noticed that it was still floating, and was now covered with a patch of fluffy white mold just above the surface.

What did I do wrong here?  How could I prevent this from happening next time?
Unfortunately...I think that other answer gave some dangerous information.

Sticking a raw pepper in oil and letting it sit out is dangerous.  Not only could the moisture cause mold apparently but sticking something like that in oil runs the risk for botulism.  

You could reduce the risk of mold by using dried peppers, but botulism is still there.