I have tried a few times to ferment pickles. While the sauerkraut has always worked, I haven't had any success with fermenting cucumbers (or green beans, which I tried once). My most recent failed attempt used a five percent brine, at the upper limit suggested on the Make Sauerkraut site. The pickles never took off. They didn't go bad; they just stayed bright green and crisp and were salty when I tried them. That was discouraging enough that I shelved further efforts for a year.
I decided to try again and to go to the lower end of the brine range. I got some mini cucs and loaded them into a quart jar, and added dill and mustard seeds in the same proportions as in making a vinegar batch: two teaspoons of mustard seed and one tablespoon of dill seed.
On day one, the cumbers were obviously fresh.
A day later, things were starting to change. The color was dulling a bit, and bubbles were appearing. This had never happened before.
After two days, it was obvious fermentation was happening.
I pulled the plug after three full days, because the house was getting warm and three to six days was suggested as the fermentation time on Holly's site. As it turns out, I pulled the plug too soon. Fermentation was underway, but they probably could've benefited from another day or two. The pH was about 4.5.
My water is about 6.6 normally, slightly acidic, so this did represent a substantial shift. I would've liked to see a pH of 3.5-4.0, however. Next time I'll let them go for a longer time. Still, this represents a modest success and is welcome.