Fixing High Final Gravity with Liquid Exo Alph-Amylase?

[geer537]

Afternoon all!

I had a very bad brew day outside a month and a half ago. Long story short; it started raining so I had to move everything inside during my mash on a cold(ish) day. My Mash Temp started to drop and I lit my turkey fryer to bring my temps back. As I moved everything inside, I over shot my temps by a lot- 170-190 f for a short period of time. I was making a brown that I have made several times. The starting gravity is usually 1.066 and ends somewhere in the 1.012-1.014 range. This one finished at 1.026. After raising the temp to 70 and rousing the yeast I got no movement so I assumed I converted the sugars incorrectly and was going to keg it. I tasted a sample and it was much too sweet for my taste so I did a little research and came accross Exo Alpha-Amylase. It was mainly used for distilling to help break down longer chains of sugars so the yeast could convert them. I figured it would be a fun experiment.

I raised the temp to 70 and roused the yeast one final time. Then I used a minute amount- about a quarter teaspoon for 5 gallons if that. The problem, if I understood right is that the Amylase doesn't know when to stop so I have to monitor it to see when (if is works) my FG would be reached and figured I'd kill the yeast off with campden tablets, keg and force carb.

I dropped some in last night and saw some activity this morning- a slight krausen where there were only a few yeast rafts before and a few bubbles in the airlock. The bubbles mean nothing and could be escaping CO2 but I plan on taking a hydrometer sample tonight and will report back. Has anyone else ever tried this with any success?

I'll update this thread after taking readings. If it works, I'll also report back on the flavor. Problem is, I don't know if I could or would want to repeat this experiment.

***I am no authority on any chemical additive- I just wanted to experiment for fun. I am posting this to get more experienced people's opinons on what I am doing. below are some photos of the krausen and amylase I am using.

 

[MrManifesto]

i've been reading "yeast" and it talks a bit about the bacteria present in those enzymes, like it's an infection worry. also, do you have to pasteurize it to denature those enzymes? either way, looking forward to hearing your results!

 

[geer537]

I read about pasteurization as well and figured killing the yeast would work in the same manner. Since I am force carb'ing this stuff, I don't need any yeast left for that. Plus I had a hard time figuring out how to pasteurize without bottling and even bottling would have been a pain to pasteurize. Campden tabs seem to be a decent alternative.

I am not trying to reinvent the wheel, just figured it was interesting and I may as well try it to see where it went.

 

[MrManifesto]

it's all good! i tried to make a non alcoholic beer for my gf, that involved a second boil after fermentation. i just rehydrated a pack of dry yeast with the priming sugar and it worked out. one thing i would have done different was not bother with dry hopping because the second boil killed any dry hop aroma/taste.

 

[geer537]

After 12 hours it dropped to 1.015 so there was definitely some movement. I actually don't have campden tablets so I am adding potassium metabisulfite to kill the yeast- about a quarter teaspoon. I can't tell from the sample is the taste is too off because it is warm and there is some carbonation in there. I'll keg it this weekend and update anyone as to how it tastes after it carbs up.

 

[geer537]

It's all carbed up and drinkable. I'd say it worked but its risky. I wouldnt try this if I were bottling. If anyone else ever has a high FG this is worth a shot. I'd love to hear if anyone else gives it a shot.