why different temps/times for milk vs veggies?

[permutations]

I like to understand things, and I'm very puzzled by something. I've been doing a lot of LAB fermentation of all kinds of things - various milks (was dairy, now cashew milk and coconut milk), carrots, cauliflower, grapes (for grape soda), ginger and honey (for ginger ale)... All these are fermented with the same LAB. I use VSL#3 as a starter.

How come veggies (like sauerkraut) are supposed to be fermented at 70 degrees for 3 weeks. But yogurt of any kind is maxed out after 24 hours, and dairy yogurt must be fermented at 110 degrees?

The LAB in all cases is thermophilic. So why does cabbage do better at 70 when LAB grows best at 110? And why does cabbage - even at 110 - take a week to ferment, while milks take 24 hours???

I know salt must play a part (slows fermentation) and the acidity of the food plays a part (also slows fermentation), but doesn't explain everything. Why are some foods better when fermented at 70 degrees, and some at 110? Does anyone know?

[Christopher Weeks]

I don't know what's in your starter, but I'm essentially certain that the bacteria we use in yogurt and vegetables are different and have different requirements. And that's why. If you're actually successfully using the same starter for both, my guess is that it includes members of various species and the ones that thrive in the conditions you place them in do the work while the others die off.

[Gutted]

You don't need to use VSL #3 as a starter, it's just wasting a very expensive product IMO. Many of the bacteria in VSL #3 don't have any use in sauerkraut. Mainly lactobacillus plantarum is what will take over after other bacteria on the cabbage do their thing and that is most active at lower temperatures. For your yoghurt, you don't want L. plantarum because it produces sour tasting yoghurt in my experience. It's not nice at all, it ruined my yoghurt when I fermented at a lower temperature of 20C which is closer to L. plantarums ideal temperature where it performs better than the other bacteria. If you ferment at higher temperatures for yoghurt such as 42/43 (107.6/110F) the other bacteria in the VSL #3 more suitable for yoghurt will be most active and will become dominant producing a more normal yoghurt.

There will be L. Plantarum in a sauerkraut wild ferment so as I said, it is a waste of VSL #3 IMO because most of the other bacteria will just die.

I don't use starters for sauerkraut, I only use starters occasionally for yoghurt and mainly previous batches. I use probiotic capsules for yoghurt such as Xtralac but they are quite weak capsules so take a long time to culture when I start a new batch. Which I very rarely do.

For sauerkraut I do add soil based organisms which help take care of mould and yeast. I have been using Bacillus Coagulans for this so far for cost reasons but I did want to use Bacillus Subtilis for it's health benefiting effects. BTW BS makes food stink! I have been culturing some from a digestive enzyme blend which has 1 billion CFU of BS using liquidized potato and it really stinks badly. I can now imagine how Natto must smell.