I always use red cabbage for my sauerkraut, because it provides a natural pH indicator. The cabbage goes in purple, but turns rosy-red as the acid is created during fermentation. If I let yeast grow (from the surface, down), the product turns blue as the yeast consumes the lactic acid. (I would not eat blue sauerkraut!)
Also, I use a double layer of waxed paper over a 1-Qt Mason jar, held on with the usual canning lid right. It keeps the dust and spores out, but prevents pressure build-up. A typical head of red cabbage fills two jars. I cut plastic disks to hold the cabbage below the brine, weighted with a small jar ("baby food") of stones. Any strip of cabbage exposed to the air becomes a pathway to spoilage.
I can't say that having sauerkraut in my diet has prevented COVID infection, but both times I tested positive, I was back on my feet in 36 hours, so (at age 65, when the youth start to warn us about frailty) I must be doing something right.
Re: Fermented foods - red sauerkraut
Also, I use a double layer of waxed paper over a 1-Qt Mason jar, held on with the usual canning lid right. It keeps the dust and spores out, but prevents pressure build-up. A typical head of red cabbage fills two jars. I cut plastic disks to hold the cabbage below the brine, weighted with a small jar ("baby food") of stones. Any strip of cabbage exposed to the air becomes a pathway to spoilage.
I can't say that having sauerkraut in my diet has prevented COVID infection, but both times I tested positive, I was back on my feet in 36 hours, so (at age 65, when the youth start to warn us about frailty) I must be doing something right.
Lathechuck