Fermentation obviously is an awesome way of preserving food or for creating that lovely fermented flavor.
Fermentation of chile peppers is becoming very popular especially in the commercial space. But with scale, also comes safety concerns.
Most larger hot sauce companies are using mash fermentation over brine to produce larger amounts of pepper mash.
We know that 4.6 is the magic pH number to prevent the growth of C. Bot – But it’s not just the pH, it’s other factors that create a hostile environment to the growth of harmful microorganisms, like salt (brine).
From what I’ve read, C. Bot takes 3-4 days to start growing. So I have a few questions in regards to C. Bot growth along with toxin production in relation to fermentation process.
How exactly and when does C. Bot grow? Does it multiply? When is the toxin from C. Bot actually get released during this process?
For fermentations, the goal is to lower the pH of your fermentation as quickly as possibly while letting the C02 push out any oxygen in the surrounding container to prevent yeast, molds etc from growing. Does this mean a fermentation is potentially unsafe if the pH of the mash / brine is still above 4.6pH before the 3-4 days (based on when C. Bot begins growing)? Or is the information I’ve gathered incorrect? Let’s say I have a pepper mash fermentation I start today, I let the fermentation sit for 3 months. I check the fermentation the day I open and process it into a hot sauce and it’s below the 4.6pH benchmark. Is it still safe? How do I know the pH was below 4.6 to prevent C. Bot. growth within 3-4 days. Alternatively, I check the pH of said pepper mash at day 2, day 3, day 4 and the pH isn’t below 4.6, but eventually 3 months later it is. Is it still safe? How can we be sure that C. Bot wasn’t growing during the period before the pH reached the equilibrium of 4.6pH and was releasing toxins during that time?
To answer you, there are some facts we need to check:
1. Clostridium botulinum replicates like most other bacteria through binary fission
2. There are 8 types of Clostridium botulinum reported based on differences in the toxin produced: A, B, C1, C2, D, E, F and G
3. These types are further cartegorized as either proteolitic or non-proteolitic in nature
4. Like any other bacteria, Clostridium botulinum strains has their optimum conditions for growth and toxin production: According to the FDA, optimum temperature for growth and toxin production of proteolytic strains is close to 35°C; for nonproteolytic strains it is 26-28°C. Furthermore, some nonproteolytic types may produce toxin at refrigeration temperatures (3-4°C)…….. for some reason.
5. Like you mentioned, 4.6 is the magic pH number to prevent the growth
6. The magic water activity number is 0.94, below which Clostridium botulinum may not grow and spores may not germinate.
Here are my observations:
- You may not conclude that Clostridium botulinum will grow based on pH value alone, the other characterisics that create a hundle for the bacteria to thrive may not be right for its growth:Water activity, oxygen concentration, alkalinity, temperature, ….. including the possible antimicrobials present in the pepper mash, etc
- If all conditions are right, then obviously, if present, it will grow and possibly produce the toxin during fermentation
The solution would be to have several hundles in place so that even though pH is still above 4.6, the spores will not germinate or the bacteria will not grow on account of temperature, or water activity, etc