Brewing with dextrose (corn sugar)

I was thinking it wouldn't change the flavor at all myself, but it was obvious that there was something different with those batches...everyone that tried those batches, around 10 people, mentioned how it was too sweet for them as well. The longer it sat around, the sweeter it got as well. If that helps identify what compounds could be present. I thought it was that the hops were fading, but beginning just a day or 2 on the keg, it started getting sweeter. Someone else mentioned cidery, but my palate picked up cheap miller high life similarities. Possibly there were compounds other than dextrose in that mixture as well? It would have to be a more complex sugar though for it to survive fermentation, correct?

 

Yes. Ale yeast's ability to use sugars/dextrins breaks down like this...
Glucose (Dextrose): fully fermentable
Fructose: fully fermentable
Sucrose: fully fermentable
Maltose: fully fermentable
Maltotriose: Generally partially fermented, varies from strain to strain.
Anything Higher: Not fermentable

I've never heard of anyone buying Dextrose that accidentally contained other sugars. It seems unlikely to me.

 

Another possibility is the likely under pitched yeast stalled after feasting on excessive simple sugar and didn't ferment the dme as well as it could have.

Using 20% dextrose in a 6-9L Tripel has never resulted in a beer that I would call sweet, which is nice because I prefer relatively dry beers in terms of style.

 

Give it a few gentle swirls to help it mix. The reason you're seeing no activity is because the yeast haven't had the chance to eat anything yet. It usually takes 12-36 hours after a healthy pitch of yeast hits fermentable sugar and all that jazz to be able to observe fermentation.