fermenting Fermentation Lifecycle

[kjwalker]

Couple more questions from an amateur...
 
At what point is the ferment safe?  I mean...once there are bubbles and gurgles and the mash is fermenting...does that mean that other problems can't creep up...like molds and yeast specifically.  
 
Has anyone made an attempt at compiling a fermentation lifecycle that shows expected activity along a timeline?  Be nice to see that....

 

[hot stuff]

Generally, the fermentation process is done about 6-8 weeks. You will first see the carbonation lift the mash and have the brine underneath it. When it is close to done, the mash won't separate from the brine. When it is thoroughly done, the brine will sit on top of the mash.

 

[RocketMan]

Hey kj, great questions and just the type of thing that should be in the Fermenting 101 thread. I'll answer it here but am going to ask a mod to add it to the 101.

CM check me on this.

A ferment isn't tryly safe till the Ph is below 4.0 and too acidic for any of the bad bacteria to survive. It is however safer once the CO2 layer has built up and no Oxygen is in there. You can still get a good growth of Kahm yeast but that isn't detrimental to the mash.

As for a lifecycle of a ferment, I believe that all frrments follow the same life cycle.
A. Reproduction of the bacteria to sufficient numbers to handle the mash.
B. Conversion of the sugars to Lactic Acid, or alcohol in the case of other frrments, and CO2.
C. Hibernation, while some of the LAB will naturally die off, as the sugars are depleted they will go into a hibernation state. if you were to take some of the juice and transfer it as a starter to s new ferment, they come back and start the process over.

Hope that helps.

 

[shortbus]

I'm a nube... but here are my observation from practice.  Without inoculation (natural LAB ferment), I've seen the most activity in the first week.  I've also added high sugar components to my ferments so the LAB has plenty of food to go after.  These have included sweet onion, carrot and red bells.  The resulting pH has been about 3.0-3.3 every occasion after 3-4 week (7-10 days on the counter then into the fridge).  Not having a food processor, I spilt the peppers in half, ferment,  then run through the Vita Mix blender after fermentation has broken down the cell structure.  
 
Intuitively, the faster the CO2 blanket forms and quicker the pH drops, the "safer" the ferment will be.  So, in order to achieve this, helping the natural LAB with a spike of introduced LAB along with more sugar will get the process going faster and the pH lower.  I plan to do this with future ferments even though "natural" has worked so far.
 
Having experience with wine making, natural yeast will ferment your grapes.  However, inoculation with a specific strain of yeast gets the process going without the risk of less desirable yeasts doing their thing first.  The increased control over the fermentation process increases the likelihood of a good, repeatable result.  
 
I'd say "safe" is achieved within the first 10 days or so based on my experience (provided the LAB takes off and starts partying down on the available sugar).  
Like wine, it's all about the aging process for flavor and complexity.

 

[SmokenFire]

Great posts RM and shortbus!

 

[slingshot13]

this is a great question!!  especially for us new fermenters
 
I know every mash is different.... but on average, how long do you guys let the ferment safely age after the fermentation stops?? 

 

[kjwalker]

Thanks for the good answers.  So...
 
1. A good start is important to get a jump start on the good LABs and thus creating a good CO2 blanket
2. Mold and yeast "can't?" survive without oxygen....???
3. Brine from a ferment can be removed, put into a small jar, and put to sleep in the fridge?  Then added to the next brine to create that desired jump start?

 

[SavinaRed]

Thanks for the good answers.  So...
 
1. A good start is important to get a jump start on the good LABs and thus creating a good CO2 blanket
2. Mold and yeast "can't?" survive without oxygen....???
3. Brine from a ferment can be removed, put into a small jar, and put to sleep in the fridge?  Then added to the next brine to create that desired jump start?

good questions as I'm a newbie to fermented foods.

 

[SmokenFire]

this is a great question!!  especially for us new fermenters
 
I know every mash is different.... but on average, how long do you guys let the ferment safely age after the fermentation stops?? 

 
I let my stuff go for a minimum of 3-6 weeks and sometimes as long as 3 or 4 months.  I'm always impressed more by the aged stuff - its complex in a way the 'junior' stuff can never be.  the ferment itself can last a long time in the fridge especially.  like a year.
 
edit: for kj
 
1. yes that's solid info
2. you might get kham yeast but it's not a problem
3. in short yes - you can 'inoculate' future ferments w 'stuff' from previous ferments similar to using probiotic capsules or sour dough hooch or kimchi juice.

 

[kjwalker]

@smokinfire....why "in short yes" on #3?

 

[SmokenFire]

@smokinfire....why "in short yes" on #3?

 
Turn of phrase kjwalker - I could go on and on about using previous batches as 'starter' but didn't.  It's something I do nearly every time though.  EXP: I will pour off some of the brine from this week's batch of sauerkraut to add to the jar for next week's batch, and I almost always use a bit of fermented pepper mash to 'inoculate' the next round when making more mash ala this thread.  We also do the same thing when making kombucha - a little bit of the previous batch gets mixed in to the new batch.  NOTE:  I do not use starters like whey or capsules - so the use of the brine/mash/etc servers to help guarantee good results.  If you're using starters then you wouldn't need to.  
 
Back when I first started fermenting I used Caldwell's tablets for every ferment I did as I was worried about things going south.  After a couple year's worth of experience I understand things better.  I still will use the Caldwell's tablets for certain things - it's a great product.  Best of luck!        

 

[oldsalty]

SMOKEN!!!!!!!!!!!!!!!!!!!!!!!!!

 

[kjwalker]

Great!  Thanks!
 
I am on my third and fourth ferment, and the fourth one is starting to go south....getting yeast and the vessel it's in is not ideal for scraping.  Today I am gonna get a new container for it and see if it's salvageable.  I already stirred some yeast into the mash though.  Is this wasted now?  Time to start over on another one?

 

[RocketMan]

NO!!!!!

If it's a yeast just leave it and let it run. It's better to let it run and keep the CO2 layer than open it and take a chance on an infection.

 

[kjwalker]

I went ahead and scraped the yeast off....then put it in the fridge.  Smells great.  No more yeast.  PH is less than 4.0...I think I'll just let it sit for a few weeks.  It's only been going for about 15 days.

 

[AldenMiller]

Good read, thanks for posting this.  My first two ferments are finishing up and should be ready to bottle in the next couple weeks.  They will both be eight weeks in the fermentation jar when I open them up.  I was glad to read about the different phases of how the ferments look, mine seem to have followed that pattern so I think all is good.
 
-Alden