Quote:
Originally Posted by seaeagle
I read some of the articles on fermentation.One expert says as soon as you see the fungal mat you are finished.
"In a few days, a layer of greyish-white mold forms on top of the water - a good sign. When that layer of mold covers the water's surface, fermentation is done. If you leave your seeds in the water beyond that point, they'll start to germinate, so be sure to check the jar often."
And others say to let the seeds ferment a few more days. I always let the ferment a a couple of days longer.So what is your opinion on this?I have some Cherokee Purple seeds that have a fungal mat now. Are the done? 
Anyone else who has an opinion, would love to hear it too |
I don't know who the experts are you refer to and I don't know if I'd be called an expert myself, but I have saved seeds for over 4,000 varieties, I do have an advanced degree in Microbiology and I do understand the mechanics of fermentation from the biological and biochemical aspects. And I have taught both med and college students same.
What is the goal of using fermentation to process tomato seeds? it's to have the fungi AND bacteria that are present in the air land on top of the tomato gunk and eventually produce enzymes that will break apart the tomato remnents always present and to remove the gel capsules from the seeds and to remove most of any tomato pathogens still attached to the seed coat, and all of that is done under anaerobic ( without O2)) conditions.
Does a mat always form atop the tomato gunk? NO. it depends on how many are in the air at any one time and also the pH of the tomato gunk. So you can get just little clumps on top of a very watery surface.
Initially the gunk is fullof 02 and after a true mat forms usually the top 1/3 will be oxygenated. Different fungal and bacteria species can be either strict aeobes, they need 02 to metabolize and replicate, or anaerobes, and some of each are called facultative since they can switch their metabolism from one to the other.
First, the 02 in the upper layer is used up by the aerobic organisms, but it takes a few days for that to happen, and also depends on the ambient temps and how thick the gunk is.
Then anaerobic fermentation takes over and the organisms, still at the top, make enzymes for the fermentative pathways, there are several with differentend products, that results in the destruction of tomato tissues, releasing any adhered seeds, as well as removing the seed gel capsules.
You know when fermentaion is working when you see gas bubbles on the inside of the container and you observe seeds falling to the clear area at the bottom of the container.
I think that covers fermentation and I'm not going to go into what one does when it's known that fermentation is complete, unless someone wants me to, but right now it's not all that high on my prirority list.
Summary? I don't agree with yourexperts and am sticking to my story.
Carolyn