Q:

Sickly sweet ginger beer, Acesulfame K? 

I've been brewing a kit Ginger Beer the last 10 days and it's about finished I think.  Starting SG was 1.041 and it's settled at 1.008.  100g of grated boiled Ginger were added, and 1kg of Muntons Beer Enhancer (spray dried dextrose and spray dried malt extract). 
I drew some off earlier, chilled it and tasted it.  There's an overly sweet false taste like someone's mixed coke zero with ginger.  I've checked the ingredients of the kit and it has Acesulfame K in it!  I thought these 'Simply' branded kits were all natural ingredients, my mistake.  
Does this 'false sweet taste' sound like the Acesulfame K to you, or could it be that I need to try and encourage the fermentation to go lower than 1.008 to mop up any final fermentables?  

A:

I'd be surprised if 1.008 tasted excessively sweet - that's not very much "regular" sugar, so it does sound like some kind of artificial sweetener.  Acesulfame K won't show up on the hydrometer, since it is 200  times sweeter than sucrose for the same mass, so very little is needed.  It does have a slightly bitter aftertaste, so I think you'll notice it. 
See

Wikipedia: Acesulfame Potassium

