Kvas is a traditional Slavic and Baltic fermented beverage commonly made from rye bread... and more information about it you can find on Wikipedia article here. But in common language we used to call a kvas everything that is slightly fermented... and I lied.. there's actually up to 1.5% of alcohol. I don't know if it makes you happy or opposite, but here I want to show how to make fizzy refreshing kvas from Oxalis acetosella or a Wood sorrel as it commonly called. You can read about its edible qualities on this wikipedia page. One thing to concidere is it can be harmful in large quontities, so don't substitute all your food with it. You can find this plant at early spring in a planty, so you can start to replenish your lacking vitamin.... I don't know, I jusyt drink it.
P.S.: This instructable is patched from two separate brewing seances... because of my expert level documenting skills. So if the kvas on different photos has a slightely different color it's because I photoshopped it badly.
Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.
So, at first we have to gather a bunch of Oxalis. I'm not specifying the amount, it's kind of intuitive stuff but you can get the rough idea from the photo (fot 2L of kvas). Also here in this particular case I'm adding some Thymus, mainly because I have...some. It's not neceserry. Kvas solely from Oxalis is ok. Kvas solely from Thymus is... not... very good.
Now, when we've got our plants gathered, we have to shake all the bugs and loose stuff off of them, wash, cut off the roots, optionally chop them, and put into suitable vessel.
Boil then some water and pour it into the pot with herbs.
Cover the pot with a warm blanket to keep the heat for longer and leave it for 24 hours or over night. It's not critical for how long you should leave it but it has to cool down before adding yeast.
On the next day take a number (according to your ammount of liquid) of plastic bottles (I use 1.5L bottles from carbonated mineral water because you can store them without cleaning and they are able to widthstand reasonably high pressure) and put sugar in them. Generaly it's ~40-60 grams per littre or 3-4 table spoons.
Then add regular baking yeast. Something about 1 tea spoon per bottle. The more you add the more active the fermentation will be.
Now pour the herb infusion in leaving aprox. 1/3 empty, screw down the caps tightly, shake to dissolve the suggar, and leave the bottles at warm place (18-25`C).
And here's the inportant part: the bottles can ACTUALLY EXPLODE (#not a click bait). During the fermentation the CO2 is produced and we want to some preassure to buid up at which point the gass starts to dissolve in water making the drink carbonatet which is what we want. But if you leave the bottles for too long they can go boom, which is also kind of cool, but is not a theme of this instructable. It happend to me only once at kind of different but similar project but solely because I was too lazy to check the bottles and even when I saw that they are clearly bulging out I did nothing. So here's what you're have to do to avoid unecessary mopping:
- Use bottles from carbonated drinks or beer as the're made from thicker stronger plastic;
- Check the bottles regularily by pushing on them with your thumb. They don't have to be rock-hard. They should be pretty firm but springy at the point when they're ready for the next step:
- If the bottle is visibly bulging out you can try to relese the pressure by accurately screwing off the cap. Than you can pour the kvas into new bottle and go straight to the next step.
I recomend to pour out the infusion at the morning so that at the evening you'll be ready to go to the next step, at which the fermentation will stop, and thus, not being in need to leave the bottles without attention over night.
Also if you're still not sure about your abbilities to take care of explosive bottles of native (ehm... native related) Slavic drink, you can leave the bottles somewhere outside or put them into secure container or maybe even carton box.
And also you can make the beverage in more traditional way, without pressurising it. Just add yeast, cover the neck of the bottle with piece of cloth an leave it for a day or two in a warm place. Then put the cap on and place the bottle with a drink into fridge... or drink it right away. In this case it will be somewhat fizzy but far not as much as with first method.
When the bottle gets firm enough (yet still flexible if push with finger) it's time to put it into the fridge. It will still keep fermenting for a some time but eventually it will cool down to the temperature at which yeasts say "Nope, I'm done. Fudge this life" (theoretically aprox. lower than 16`C). CO2 will stop producing. Cooll the drink to the temperature at which you prefere it to be drunken and... it's ready.
It may seem to be a little bit complicated with all this explosion hazzards and pressure timing but it all can be done purely intuitively, especially with having some experience. Personaly I'm making this kvas (and similar recipes) for 3 years and I haven't had any exidents. It still can splatter all the kithen when opening the bottle, in case if the pressure is a bit too high... but hey!.. it's Spring... Summer... it's refreshing!.
The drink itself is rather nice and refreshing, althoug with herbs that appear at more late periods of the season you can get even better tasting breverage. I'll show some recipes later, but as you, probably, can guess, you can use any herbs or juices to provide carbonated drinks this way. Just be mindfull about what are you doing and do the research.
Some precipitate of dead yeast will deffinetely occure. I can't see the way to get rid of it because as soon as you open the bottle the whole thing starts to fizzing and bubbling mixing it all up so you can't pour the liquid accurately leaving the precipitate. But as soon it's not deadly I'm totally ok with it.
The one, one one the photo was made with differrent herbs. In case with Oxalis, the drink has more green-ish color.
This is it. Thanks for the attention and have a nice kvas.