Stopping added ezymes added during fermentation

If amylase was added during fermentation to convert an incomplete starch conversion. How can it be stopped without boiling.

Once fermentation is complete can the temp be raised to 170 (alchol boil 173f) for a certain period then reduced to normal, then yeast repitched for bottling?

The amylase would have been working at 72F, so I'm guessing this would take a week to finish conversion.

Reason I'm asking is I thought I had no conversion due to my post here: Potential Gravity for Tapioca starch???

So I added some amylase to the fermenting beer. About 1.4 grams for 5 g. (.05 ounces)

Good question. One the one hand, once all of the starch has been converted the enzymes have nothing else to do. On the other, heating the ale enough to de-nature the enzyme might damage the flavor and drive off some of the alcohol. Enzymes are very specific in the activity. If I was faced with the decision, I'd just let it finish fermenting and not worry about it.

Where did you buy the enzymes. They might be handy to have around. Actually, I know from experience that they would be, I've just never tried to track any down.

I second D42's suggestion to just ride it out... in fact I sort of doubt that you'll get much of anything from adding enzymes in the primary; alpha amylase is really only very active between 155 and 165 F (Here's a nice chart that demonstrates all the various enzymes & their functional temperatures), and beta only active a bit below that. At primary fermentation temps, I doubt you'll get any breakdown at all, or just a few percent at best. If you're going to heat it now you might as well re-mash and re-pitch.

David_42: I actually found a bottle of beta amylase at either San Francisco Brewcract (in SF, CA) or Fermentation Frenzy (in Los Altos, down on the peninsula); I don't remember which. They both do mail order, but neither of them list enzymes in their online catalogues... you could try calling and asking if they'll ship you some, but I haven't found any locally or online, either. Try sfbrewcraft.com and fermentationfrenzy.com.

Yeah, I know they are most active at those temps, but I've read that some breweries add them in the secondarys to lighten the body even further for dry lagers etc. It's supposed to take weeks at those temps.

I guess I'll just let it finish out. and see what happens.

Since this was post mash/boil I used Digetstive enzymes,

The protease should help reduce protien haze, amylase for the starches, the other tow enzyems don't have any effect on beer. 10 capsules equelled 1.4 grams of amylase, which I beleive is the recomended amount.

Finally got a hold of my garin supplier (Brewpub) and I should get my grains for my AG next week.

I agree with everything said before, but would like to add that heating to 170 would surely kill the yeast, just adding to the problems.

-a.