Fermentation Problems

[njurbanshiner]

@ njurbanshiner
That is an excellent example of an iodine test showing a complete conversion. Well done! That said, I'm sure as you gain experience with mashing, you will eventually not bother with doing an iodine test. Many here, myself included, don't bother.

Thanks! That test this morning was a nice way to wake up I'll probably keep testing since I did buy this bottle of iodine...

I sat my fermentation bucket outside today just to get the yeast a bit more heat than what I'm willing to run my thermostat. Bad news? A thunderstorm rolled through this afternoon and my bucket was soaked. Good news? I saw my airlock burp! That wouldn't have happened without water in there...it was definitely fun to see.

Just to check with the experts...what now? Do I just wait? The books I read (the ones that made this all seem so easy to begin with...and NEVER mentioned something as simple as an iodine test) pretty much just said give it 2-4 days and then--voila!--I'm ready to run it. Should I be stirring? Shaking? Taking measurements? I'd rather do too much work than not enough, but I also don't want to disturb the yeast's work. Right now I have a nice cap, a LOT of action (it sounds like fizzing champagne and smells like apple cider, and I get a little lightheaded when I take a deep breath--I'm guessing that's CO2). Now I'm having fun!


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[MitchyBourbon]

Yup, just give it time and maintain even temp control as indicated by the yeast you are using. When the air lock stops bubbling you can take a gravity reading. Then wait a day and take another reading. When the gravity stops going lower your ready to distill.

[njurbanshiner]

My DADY says it is good below 90°. I can either leave it inside (thermostat near 70°), leave outside (forecast highs mid 90s/lows mid 70s, but I don't get much direct sunlight so I'm not worried about cooking the yeast), or some combination. The yeast will produce some of their own heat, so how much should I factor that in?


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[MitchyBourbon]

Big temp swings aren't good for fermentation. If the package your yeast came from states a preferred temp range, I would use it and try to keep it steady.

[njurbanshiner]

Big temp swings aren't good for fermentation. If the package your yeast came from states a preferred temp range, I would use it and try to keep it steady.

Thanks so much, MitchyBourbon. I'll just keep it inside the rest of the time for consistency. May slow down the fermentation but I hear that makes for nice esters anyway


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[skow69]

@ njurbanshiner
That is an excellent example of an iodine test showing a complete conversion. Well done! That said, I'm sure as you gain experience with mashing, you will eventually not bother with doing an iodine test. Many here, myself included, don't bother.

Also, if you want to know if your enzymes are still working you can use the iodine test to tell you. You probably won't watch to bother with this either cuz it's way too much effort. Anyhow, here's how:

Take a sample and divide it between 2 shot glasses.
Do an iodine test on one glass if that test shows a good conversion then proceed.

Add a very small pinch of corn starch to the second shot glass. Stir.
Put half of this into a third shot glass.
Now quick do an iodine test on the remainder of the second shot glass. It should show that unconverted starches are present.
Now warm the third shot glass to 150 °F for 20 min.
Do an iodine test on the third shot glass.

If it shows that no starches are present then you know your enzymes are still active.

That is an ingenious test. I have always assumed that the enzymes keep working, albeit slowly, until they are eventually denatured in the still, but it is just a theory, I have never seen any evidence.

I ran out of iodine about a year ago, but I might have to get some just to try this and see what I get. After all, there have been several times in this hobby that my assumptions turned out to be complete bullshit.

[der wo]

I have always assumed that the enzymes keep working, albeit slowly, until they are eventually denatured in the still, but it is just a theory, I have never seen any evidence.

Here is a study:
http://onlinelibrary.wiley.com/doi/10.1 ... 0425.x/pdf" onclick="window.open(this.href);return false;" rel="nofollow
A comparision of mashing with and without boiling the enzymes to death. The enzymes keep working, IF they weren't heated too much. It's not 100% on topic, because it's Malt whisky and of course without adding enzymes.

Here some infos from an old German study about destroying temperatures of enzymes:
viewtopic.php?f=3&t=59760" onclick="window.open(this.href);return false;" rel="nofollow
They recommend much lower temps for mashing at least with fine milled starch to save the enzymes.

With liquid enzymes we have two advantages: Firstly the high temp alpha amylase is such a fast beast, that we can get a good iodine test before fermentation, so all starches are converted in fermentable and unfermentable sugars. Secondly the glucoamylase is able to work without problems under the sour environment while fermentation, so it will make everything fermentable while fermentation.

[njurbanshiner]

Update:

Fermentation has been going for almost a week now (started last Monday morning, now Sunday afternoon). I still have corn and yeast at the top of the mash and some bubbling and fizzing going on, but it's slowed down quite a bit. Last night (Saturday) I measured 1.004 (OG was 1.074), so I think I'm going to go ahead and run it tomorrow (Monday). Is there any benefit to NOT going ahead and running? If not tomorrow I will have to wait until Thursday and I really don't want to risk spoilage.


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[rad14701]

Update:

Fermentation has been going for almost a week now (started last Monday morning, now Sunday afternoon). I still have corn and yeast at the top of the mash and some bubbling and fizzing going on, but it's slowed down quite a bit. Last night (Saturday) I measured 1.004 (OG was 1.074), so I think I'm going to go ahead and run it tomorrow (Monday). Is there any benefit to NOT going ahead and running? If not tomorrow I will have to wait until Thursday and I really don't want to risk spoilage.


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Your wash won't spoil if you wait until it is completely done and cleared... Patience...!!!

[njurbanshiner]

Your wash won't spoil if you wait until it is completely done and cleared... Patience...!!!

Thanks. My biggest worry was it finishing Monday night and then just sitting for over 2 days (day job gets in the way...). I'm surprised it's taken this long but I'll be patient...not easy since I'm excited for my first run!!


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[rad14701]

Your wash won't spoil if you wait until it is completely done and cleared... Patience...!!!

Thanks. My biggest worry was it finishing Monday night and then just sitting for over 2 days (day job gets in the way...). I'm surprised it's taken this long but I'll be patient...not easy since I'm excited for my first run!!

You're better of waiting... Washes don't usually spoil unless they are already infected... If you are using an airlock there is nothing to worry about... Some of us keep completed washes under airlock for many months before running... You'll have better luck if you have patience and wait for things to finish... You'll have less chance of foaming or puking...

[shadylane]

Just a thought
Patience and let it finish.
But, if you had mashed with malt, it would be a race between the yeast and bacteria

[njurbanshiner]

Just a thought
Patience and let it finish.
But, if you had mashed with malt, it would be a race between the yeast and bacteria

So much of what I had read made me paranoid about (unintentional) bacteria. Didn't realize that was mainly something to worry about with malt.

I'm going to let it finish (thanks for all the advice!), but I'm really surprised it's taking this long. I expected 2-4 days, and now I'm at a full week.

Here's hoping my patience will be rewarded with delicious corn liquor...


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[njurbanshiner]

Update: finished the fermentation after 10(!) days. FG 0.994, so I'm at 10.3% alcohol. Success!

Now doing my stripping run, but it's coming out at a much higher ABV than I expected. Per the calculations page on the home site, I expected (through 70 minutes) to have collected about 1 gallon at 28.72% ABV. Instead I was at 1/2 gallon at about 54% ABV. So it looks like that stripping run is giving me a full proof spirit. Since I didn't make any cuts for my foreshots I'm going to just keep collecting as long as I keep getting alcohol, then water it down and do a spirit run.


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[njurbanshiner]

Finished the run. End result 70oz at 80 proof. Slight bite and nice sweetness at the end.

Thanks to everybody for the help. I'm really enjoying this!!!


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[Mikey-moo]

I'm surprised it's taken this long but I'll be patient...not easy since I'm excited for my first

You've done your 3 cleaning runs though... right?

[njurbanshiner]

I'm surprised it's taken this long but I'll be patient...not easy since I'm excited for my first

You've done your 3 cleaning runs though... right?

Yes. Did my sac run just before my stripping run yesterday.


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[Mikey-moo]

Coolio