Reddit mentions of Amylase enzyme - 1.5 oz.

Buckets are really better as primary fermentation containers if you're using fruit, since it's easier to stir things up and mix the layer on top back in. This should still be fine, just try capping it and rolling it around a bit to mix that floating layer back in.

Also, when using real fruit, a bit of amylase enzyme can help break down the starches.

What you could do is mix some rice up with Amylase and then any old wine yeast should do it. Just taste it to make sure its sweet and you should be in business. Just make sure that the rice isnt to warm when doing so or you will denature the enzyme.

The enzyme in your spit that breaks down sugars is amylase. Sweet potatoes, and most grains contain their own versions. You can also buy it if you don't want to be spitting and chewing corn.

/u/h22lude is most likely correct - at that temperature you denatured the enzymes.

Good news, I did this too not too long ago, and experimented with a fix (for beer, and for science!). Go to your LHBS (or Amazon) and purchase a small bottle of amylase enyzme and add it to your fermenter in the recommend quantity.

Details from my experience here:

https://www.reddit.com/r/Homebrewing/comments/cf0j79/final_update_high_final_gravity_stalled_ferment/

They might have been me, I got it here for $6 but I have prime so shipping was free. http://www.amazon.com/dp/B006O2D7DA/ref=wl_it_dp_o_pd_nS_ttl?_encoding=UTF8&colid=3FAGUJBXPTFO9&coliid=I3L46QN44AF7GG

Amylase is likely the enzyme used to break the starches down to maltose.

Typically one would need a bit of heat and the proper pH range for amylase to do its thing.

Something like this Amylase enzyme - https://www.amazon.com/dp/B006O2D7DA may do the trick.

Shouldn't be, it's just amylase or alpha-amylase.

Quite a few sources on Amazon as well eg http://www.amazon.com/Amylase-enzyme-1-5-oz/dp/B006O2D7DA/ref=sr_1_2?ie=UTF8&qid=1395076770&sr=8-2&keywords=amylase