To learn more about concentrated lactic acid sourdough (CLAS), please see here and here.
Among the cuisines of various regions of China, there are two sauerkraut dishes that I really like, and both are made with seafood. One is called "sauerkraut squid", a popular stir-fry dish in Hong Kong, and the other is called "sauerkraut fish", a famous soup from Sichuan. In both recipes, we use sauerkraut made with mustard green, or in the absence of mustard green, a vegetable called "snow red". We refer to sauerkraut as "Haam Shuen Choi" in Cantonese, or "Suan Cai" in Mandarin. This Choi (veggie) is both salty and sour, as the name denotes. When I was a kid, if I remember correctly, we always bought Haam Shuen Choi from the marketplace, where they were displayed in the open and sold whole.
These days, I can find packaged Haam Shuen Choi in Asian supermarkets in the U.S. While they may look similar to the Haam Shuen Choi from my childhood, they taste terrible, probably because they are preserved with chemicals. So, I've stopped buying them and made my own with CLAS in the Instant Pot. To make pickled veggies, I've tried using mustard greens, "snow red", carrots, cabbage, cucumbers, etc. The IP-CLAS combo works perfectly for them all. In just 24 hours, I can have crunchy, sour veggies ready to go. In the past, we always had to soak the Haam Shuen Choi first and add a fair amount of sugar to balance out the flavor during the cooking process. Otherwise, it would be too sour and salty. There is no such problem with IP-made Haam Suen Choi; I can use them as-is.
It's super easy. All you need to do is put the veggies in the Instant Pot, cover them with water (Measure how much water is used. I usually fill it close to the rim, then put a porcelain plate on top, and loosely cover with the IP lid to weigh it down so that the veggies are fully submerged.), and season the water to your liking (I usually use 2.5% sugar and 2.5-3% salt of the water used, and plus whatever spices I feel like adding at the moment). Then add some CLAS (3% (liquid + whole rye flour) ) and some fresh whole rye flour (3%). Then select the "yogurt" function (42C), wait 24 hours, and you're done. By that time, the pH is ~3.5. How easy is that! I strain the liquid and drink it daily as my "probiotic drink". I can use the filtered sediment as a second starter for the next batch, but of course, this step is not necessary.
P.S. On second thought, I'll probably backslop the sediment, so I don't have to use my CLAS every time. I'll use CLAS initially and hope it will self-propagate in each batch as new food (fresh whole rye flour, sugar, etc.) is added. I'm hoping this is doable and not just wishful thinking.
I my Instant Pot. It is a handy tool to have in my kitchen. I use it to make my beloved CLAS, and I also use it to simplify the process of making marmalade.
24-hr "snow red" Suen Choi
36-hr "snow red" Suen Choi
Sauerkraut Squid
https://youtu.be/mW-WTDV58DQ
Sauerkraut Fish
https://youtu.be/h_RtbERVPg8
My simplified version of sauerkraut fish using fish filet
I can slice the filet thinly when it's still slightly frozen.