If you have never had fermented carrots, they taste like an effervescent, tangy (kind of pickle-like) flavor.
The following will be my breakdown of days, flavor, and my favorite.
In order to ferment vegetables and in this case carrots, it is critical to use salt in each ferment.
For each quart I made the same salt water brine ( for your purpose you can do the same ferment to all three jars):
3 quarts mild-warm water
1.4 ounces kosher salt
2.5lbs pealed speared carrots
3 regular mouth quart canning jars
Put salt and water into bowl, whisk until salt dissolves ( this is called your brine). Set aside to cool to room temp. Take sliced (like pickle spears) carrots and pack them into jars. Push them under the shoulder of the canning jars. This is why I like regular mouth, it keeps the carrots under the brine for the ferment. If you so chose you can add flavorings to each jar such as garlic ginger, or bay leaves. I kept them plain to taste the ferment exactly in each experiment. Now, pour the cooled brine over the carrots (add culture if desire as follows), place towel of the top of the jar and rubber band down to keep flies and other particles from getting into your ferment. The following are what's in each quart.
#1= nothing, no starter
#2= 2 tablespoons unflavored water kefir
#3= 2 tablespoons whey
Typically, today most people ferment 3-7 days. But waiting up to two-four weeks the flavor intensifies. I chose to ferment these 6 days. I tasted them on day 3 and day 6.
#1= slight fermented taste- very crunchy
#2= more fermented flavor than #1, little less crunchy. I like this a lot. Starting to get white film mold ( completely normal, kahm yeast layer) scraped off.
#1= Nice ferment, still crunchy not too far fermented flavor for me. Kham present , scraped off.
#2 Excellent flavor, little effervescent, I like that. And still medium crunch.
#3 Ok flavor, but I liked it better at day 3. More cloudy the longer it sits compared to the others. Not nearly as crunchy- which is fine just fermented faster. Grew kahm faster than water kefir starter.
Overall, I loved the water kefir starter culture. It got a faster ferment than the one without a culture- I like that one too- but if I needed to do a faster ferment I would choose the water kefir starter method. If not, I would simply use no starter, just the brine. The starter with whey was very fast and I don't presume I would always get to it in time of where I liked the flavor. Once you like that flavor for the particular day, write it down and put a lid on the jars and refrigerate until you want to eat. Now start benefiting from fermented vegetables!