Bread Kvass on a Tepache Starter

I was too lazy to go to the Slavic store and buy store-bought kvass for okroshka, so I decided to make kvass at home. What's important is that I was looking for a recipe without commercial yeast (and I didn't have a sourdough starter either) and eventually came across a rather unexpected scheme: the kvass turned out great on a tepache starter.
A few definitions:
Tepache is a Mexican fermented drink made from pineapple peels, which is used in this recipe to start the fermentation process.
Starter is a liquid with already active bacteria and yeast that will ferment anything. In simple terms, microorganisms feed on sugar, release acids, alcohols, and carbon dioxide, so we get unsweet drinks with bubbles, curd, fluffy tartine dough, and more.
The world of fermentation is very diverse: some microorganisms love oxygen, others work only without it; some are comfortable in the heat, others in the cold; some produce more acid, others more gas or aromatic substances.
By the way, the raisin starter - which is recommended in all recipes - showed almost no activity, apparently, the Portuguese raisins are washed too well, there's not enough microflora on them, but the pineapple one worked from the first try.
So, here's the tepache recipe!
For 1 liter of water:

• peels and core of 1 pineapple
• 100 g sugar
• 1 liter of room-temperature water
  Mix everything in a jar, cover with gauze, and leave at room temperature for 2-4 days. The warmer the room, the more intense the reaction will be. My apartment is always around 24°C in the summer, so all processes go smoothly.
  When bubbles appear, a light sourness and fruity aroma - the starter is ready. If you close the jar tightly and leave it for another day in the heat, the drink will be carbonated. If you put it in the fridge, fermentation will almost stop.
  Kvass
• 130 g rye bread (I used regular toast bread with added rye flour)
• 2 liters of hot water
• 150 ml active tepache
• 50 g sugar
  Dry the bread well in the oven until it's dark brown, the darker it caramelizes, the darker the kvass will be. Pour hot water over it and leave for 4-6 hours, strain, add sugar and tepache. Leave to ferment at room temperature for about 3 days. I have a large glass jar with a spigot, so it's convenient to test the drink every day, stop the processes based on taste. Of course, you can also make an alcoholic version, why not! During this time, the bread infusion turns into a full-fledged kvass - acidic, refreshing, with light fruity notes from the starter. Again, if you close it tightly and leave it for another day, it will carbonate. For the next batch, you can leave some of the finished kvass or part of the active tepache - then the new kvass will start even faster.