Dry Beer Enzyme - what does it do?

[CrownCap]

[Not too sure where to post this, but as AG brewers seem less likely to use it I went for Kits]

Due to the infamous Muntons stuck ferment I resulted to some Brupaks Dry Beer Enzyme last night.

I peeled off the Brupaks label to see the ingredients underneath: Dextrose, AMG enzyme. Now AMG (Amyloglucosidase) breaks down starches and dextrins to glucose (dextrose). No problem,as I expected.

My question revolves around the fact that my beer went from 1017 to 1012 in about 18 hours. Now is that the effect of the enzyme breaking down the dextrins causing a lowering in density of is it truly the yeast fermenting those products out to ethanol?

I ask since the wort still tastes quite sweet, leading me to think its just the enzyme action causing the sudden drop in SG.

[CrownCap]

Agreed (and that's not necessarily a bad thing), but something has happened quite rapidly and I wonder if anyone can shed some light on whether I might of just broken down some sugars or actually fermented out some loverly alcohol

[David Edge]

CrownCap:

My question revolves around the fact that my beer went from 1017 to 1012 in about 18 hours. Now is that the effect of the enzyme breaking down the dextrins causing a lowering in density of is it truly the yeast fermenting those products out to ethanol?

The measured gravity will change if sugar / extract is eaten by yeast and turned to alcohol which has only 0.8 of the gravity of water. It will also drop if you don't de-gas the sample and the CO2 bubbles buoy the hydrometer up. Both however would reflect fermentation taking place.

The action of the AMG is just to break links between glucose molecules. I can't see that making an appreciable difference to wort gravity.

The interesting question is when the fermentation will stop. In ultra-high gravity beers the yeast conks out but the AMG carries on leading to some thinning, but at 1150-1200og it's tolerable. In a standard brew, will it continue to ferment below 1.000?

[CrownCap]

Thank David, I kind of assumed that the drop in gravity was solely down to the action of the yeast rather than that of the enzyme but wanted to get some views on that.

As for when it will stop, we shall see. Its down to 1005 last night and still has decent enough body to keep it drinkable but the airlock is still showing the occasional bubble so I don't think its quite done yet!