Stuck fermentation.... again....

[conspiccus]

To be fair the alcohol thermometer may have been dropped a few times so the fault is probably down to the user

When solving an attenuation problem, you can (and should) throw AA right into the fermentor. Bring the fermentor to room temperature. If the majority of the grains was barley, you should see a further drop in gravity. With AA, your 1.060 beer should end up at around 80% attenuation, or about 1.012.

But normally, there's no benefit to using AA in the mash because it's already in the barley. A proper mash doesn't require it, except in the case of making light lagers and such where maximum attenuation is desired. In that case, other enzymes like gluco can help a lot.

Alpha amylase enzymes is the SAME thing that's in the barley already. That's why we mill grain and mix it with water - to get the AA to meet the starchy sugars and reduce them to smaller sugars. Without this enzymatic conversion, the yeast would not be able to ferment the original large sugars.

Heating the mash greatly increases the enzyme's rate of conversion. Once milled and wet, the bacteria in the barley will begin to ruin it, so we want to get the sugar conversion done quickly, then move to the boil where we kill the souring bacteria. But TOO hot and the enzymes are permanently damaged (denatured). Too cool and the enzyme activity is low and perhaps won't fully convert. NOTE: given enough time, the enzymes would indeed do the conversion - even at room temperature.

Thanks for that really clear explanation about AA! I think I will leave the RyePA in the fermenter with the AA for a few weeks at least to allow the gravity to come down. Do you have any info about the difference between AA and GA?

 

[passedpawn]

To be fair the alcohol thermometer may have been dropped a few times so the fault is probably down to the user

Thanks for that really clear explanation about AA! I think I will leave the RyePA in the fermenter with the AA for a few weeks at least to allow the gravity to come down. Do you have any info about the difference between AA and GA?

I've used gluco in light lagers myself. I think it shaved a few additional gravity points off the final beer. Like I said though, you don't want that in your IPA until you've exhausted better options.

If the gravity doesn't budge a week after the AA, you're going to want to do SOMETHING. In addition to the AA, dump a packet of dry yeast in there now. That should cover all the bases I'd think. I suppose if you try these things and you see no effect, gluco (and even the evil Beano) are options. Your beer has enough alcohol in it now to protect it from infection, so you have some time to experiment.

 

[IslandLizard]

dump a packet of dry yeast in there now.

I seriously doubt that will change anything:

I used 15g (0.5oz) safale US-05. OG was 1.058.

That's a pitch of more than 1 retail pouch (11.5g) in only 11 liters of 1.058 wort. That's more than plenty, unless the yeast was damaged.

Yeast is not the problem. But the OP may have mashed as high as 88C...

 

[conspiccus]

How much off was it?
Just out of curiosity, and having a data point.

When pulling the alcohol thermometer out of the case it reads 5*C and when I put it in room temp water it didn't even move. It only moved up once i ran hot tap water. When I brewed this last weekend thermapen showed 66*C mash and the alcohol thermometer showed 56*C so it was a difference of 10*C which obviously is pretty big.

Not dissing the alcohol thermometer, it may or may not have been dropped a few times in it's life, so probably more of a user fault

 

[IslandLizard]

When pulling the alcohol thermometer out of the case it reads 5*C and when I put it in room temp water it didn't even move. It only moved up once i ran hot tap water. When I brewed this last weekend thermapen showed 66*C mash and the alcohol thermometer showed 56*C so it was a difference of 10*C which obviously is pretty big.

Not dissing the alcohol thermometer, it may or may not have been dropped a few times in it's life, so probably more of a user fault

Some alcohol thermometers can be slow to respond and imprecise, those are intentionally built that way, averaging temps over a minute, or even a few minutes.

If yours was reading 10C under the Thermapen, you may well have mashed at 78C instead of your intended 68C. That might explain much of your unintended high FG right now.

If that's the case, your fermentation isn't "stalled," the yeast you pitched simply can't ferment any lower, it can't digest (metabolize) the higher sugars and other unfermentables (e.g., maltotriose and dextrins) in your beer, as it is. Having a good portion of unfermentables is good in a low gravity/low alcohol Mild, much less useful in a Pale Ale.

 

[passedpawn]

I seriously doubt that will change anything:

That's a pitch of more than 1 retail pouch (11.5g) in only 11 liters of 1.058 wort. That's more than plenty, unless the yeast was damaged.

Yeast is not the problem. But the OP may have mashed as high as 88C...

Last year I used liquid yeast in a lager - both pouches failed to ferment. They were both mostly dead (Wyeast pouches bloated, but just a little). So, it happens.

Anyway, more yeast can't hurt anything. I wouldn't hesitate to do it.

 

[IslandLizard]

Last year I used liquid yeast in a lager - both pouches failed to ferment. They were both mostly dead (Wyeast pouches bloated, but just a little). So, it happens.

Anyway, more yeast can't hurt anything. I wouldn't hesitate to do it.

That's different though, failing to ferment vs. fermenting down to a certain point, which is not failure.
The yeast she pitched proved she was healthy, and fermented as far as she could. It was also quite a royal pitch.

There's plenty of yeast in there after fermenting it down about 1/2 way. Hopefully the GlucoAmylase serves up some digestible sugars she can then ferment.

 

[bracconiere]

@conspiccus when i was making 100% rice beer, alpha goes into the mash...but if i didn't add gluco to the fermenter, i'd get attenuation like what you're describing....(gave me the runs something fierce, dextrins are soluble fiber)....alpha is a random chopper, and gluco is a fine detail worker....

in a mash, it's actually beta that is the fine detail worker, but it denatures pretty quick at high temps....that's why there's a "mash window", you need both the alpha and beta working....but as far as i know, no one sells beta amylase, so it's gluco, and it will finish at 1.000 (or less)


(making the rice beer is how i discovered gluco in the first place! a 20lb bag is cheap and i'd get a decent drink, with dry hopping, 10 gallons 7.5% ABV for one of these

https://www.walmart.com/ip/Great-Va...BS6FDZAYxtMo1tYbCTVIY_zCmwieGmh4aAtfMEALw_wcB
of course that's off-topic, sorry, but gluco will make it go to 1.000, and it will be like a Brüt IPA, low calorie for day drinking)


edit: just like proteins are balled up amino acid formed with the easy to form amide bond, starches are similar, think long chains of legos, alpha randomly chops them, and gluco makes sure to cut them small....

 

[conspiccus]

@conspiccus when i was making 100% rice beer, alpha goes into the mash...but if i didn't add gluco to the fermenter, i'd get attenuation like what you're describing....(gave me the runs something fierce, dextrins are soluble fiber)....alpha is a random chopper, and gluco is a fine detail worker....

in a mash, it's actually beta that is the fine detail worker, but it denatures pretty quick at high temps....that's why there's a "mash window", you need both the alpha and beta working....but as far as i know, no one sells beta amylase, so it's gluco, and it will finish at 1.000 (or less)


(making the rice beer is how i discovered gluco in the first place! a 20lb bag is cheap and i'd get a decent drink, with dry hopping, 10 gallons 7.5% ABV for one of these

https://www.walmart.com/ip/Great-Va...BS6FDZAYxtMo1tYbCTVIY_zCmwieGmh4aAtfMEALw_wcB
of course that's off-topic, sorry, but gluco will make it go to 1.000, and it will be like a Brüt IPA, low calorie for day drinking)


edit: just like proteins are balled up amino acid formed with the easy to form amide bond, starches are similar, think long chains of legos, alpha randomly chops them, and gluco makes sure to cut them small....

So the next question is how much to add? and how long does it normally take to bring the SG down?

 

[dmtaylor]

So the next question is how much to add? and how long does it normally take to bring the SG down?

My advice - use less than you think you need, and it takes much longer to ferment out than you think it should. We‘re talking like 1/8 teaspoon, and 4-6 weeks to complete the fermentation.If you keg, it doesn’t much matter, but if you bottle you could end up with gushers or bombs if you bottle too soon. Fermentation should pick up again but very slowly in my experience.

 

[bracconiere]

So the next question is how much to add? and how long does it normally take to bring the SG down?

i add ~12-13 grams to a 10 gallon batch.....and i'd guess it'd take about 3-5 days to go dry....but i always pitch my yeast and gluco at the same time....

 

[passedpawn]

My advice - use less than you think you need, and it takes much longer to ferment out than you think it should. We‘re talking like 1/8 teaspoon, and 4-6 weeks to complete the fermentation.If you keg, it doesn’t much matter, but if you bottle you could end up with gushers or bombs if you bottle too soon. Fermentation should pick up again but very slowly in my experience.

I suggest the opposite. Use more than you need. There is a limit to what enzymes can do. I think it 's best to get to that limit asap.

 

[conspiccus]

UPDATE: after adding a bit of the AA and GA, I have checked the gravity (31/08/2020) now about 2 and a half weeks from my original post and the gravity is reading 1.002! So a massive decrease and I plan to leave it in another few weeks. Looks like we were right about this issue, but I am wondering what effect this will have on the final taste of the beer? It smells and tastes very alcoholic and the ABV calculator comes in at 8%. Thoughts?

 

[dmtaylor]

You answered your own question. Alcohol. And, it will be very thin and watery, no body, and head retention might be poor or non-existent. As I said previously, use less enzyme than you think you need.

 

[passedpawn]

You answered your own question. Alcohol. And, it will be very thin and watery, no body, and head retention might be poor or non-existent. As I said previously, use less enzyme than you think you need.

The problem was using ANY gluco. That is why it finished so low. I don't want to get into a war over this, but the alpha amylase enzymes won't ferment that far, regardless of how much is used.

Apparent Attenuation limit:

• Alpha: 80-85%.
• Gluco: 90-95%.

 

[passedpawn]

UPDATE: after adding a bit of the AA and GA, I have checked the gravity (31/08/2020) now about 2 and a half weeks from my original post and the gravity is reading 1.002! So a massive decrease and I plan to leave it in another few weeks. Looks like we were right about this issue, but I am wondering what effect this will have on the final taste of the beer? It smells and tastes very alcoholic and the ABV calculator comes in at 8%. Thoughts?

Maybe you'll like it. I made a belgian beer once that was so alcoholic, it was like drinking some type of fuel. Gah. But a buddy of mine loved it (and drank it all in a hurry). Most people, though, consider high-ABV low-body beers to be difficult to drink.

 

[conspiccus]

The problem was using ANY gluco. That is why it finished so low. I don't want to get into a war over this, but the alpha amylase enzymes won't ferment that far, regardless of how much is used.

Apparent Attenuation limit:

• Alpha: 80-85%.
• Gluco: 90-95%.

Would alpha alone have worked in the fermentation stage? As I said in an earlier post, some places on the internet claimed it would and others said it wouldn't. I guess what I should have done was waited a few weeks after adding the AA and taken a gravity before adding the gluco to see what effect each had individually. Oh well, live and learn.

 

[conspiccus]

Maybe you'll like it. I made a belgian beer once that was so alcoholic, it was like drinking some type of fuel. Gah. But a buddy of mine loved it (and drank it all in a hurry). Most people, though, consider high-ABV low-body beers to be difficult to drink.

Based on the small taste I had from my gravity sample, I have a feeling it will be difficult to drink. Will bottle anyway and see -- it was a small(ish) batch so not too much beer wasted but I am keen to try this brew again the right way because the rye came through really well

 

[passedpawn]

Would alpha alone have worked in the fermentation stage? As I said in an earlier post, some places on the internet claimed it would and others said it wouldn't. I guess what I should have done was waited a few weeks after adding the AA and taken a gravity before adding the gluco to see what effect each had individually. Oh well, live and learn.

Alpha alone PROBABLY would have been perfect. As I've said too many times, it's exactly what is in barley already and is the normal enzyme for making beer. However, for reasons that elude me, there are stories here where it did not help a stuck fermentation.

IMO, if you have a stuck fermentation and add alpha enzymes and additional yeast, this will correct the problem 100% of the time and result in a drinkable beer. But that's theory according to me

 

[Beermeister32]

It works.