Kombucha is a fermented tea drink. A living culture of bacteria and yeast, called a SCOBY, eats the sugars in sweetened green tea and turns them into acids, bubbles and flavour. Rudy's adds real fruit, ferments in Kuldīga, Latvia, and cans the result at 330 ml without pasteurising it.
Kombucha is sweetened tea fermented by a living culture of bacteria and yeast.
Rudy's ferments green tea, then blends in real fruit juice and fruit puree.
Every can is 330 ml, unpasteurised, and brewed in Kuldīga, Latvia.
The short version
Kombucha starts as tea. Green tea is brewed, lightly sweetened, and handed to a kombucha culture: the SCOBY, a symbiotic culture of bacteria and yeast that looks like a pale, rubbery disc. Over days of fermentation the culture eats most of the sugar and produces organic acids, carbon dioxide and a trace of alcohol.
What it tastes like
The result is tart rather than sweet, lightly sparkling, and closer to a dry cider or a sharp lemonade than to a cordial. Rudy's blends fruit juice and fruit puree into the finished kombucha, so each can tastes of the fruit on the label: pineapple juice 20 per cent in Pineapple & Peach, raspberry juice 12 per cent in Raspberry & Basil, and so on down the range.
Where ours comes from
Rudy's Brewing Co. is an independent brewery in Kuldīga, Latvia, started in 2019 by a couple and their dog. Every batch is fermented, blended and canned there, in 330 ml cans sold in packs of nine. The kombucha took gold at the World Kombucha Awards in 2023 and again in 2025.
Not the same as Hard Kombucha
Ordinary Rudy's Kombucha is a non-alcoholic drink under 0.5% ABV. Hard Kombucha is a separate range, fermented on with champagne yeast to 4.5% ABV and sold to adults 18 and over (20 and over in Sweden and Lithuania).
How is Rudy's Kombucha made?
We brew green tea, sweeten it lightly and let a kombucha culture ferment it for days until most of the sugar is gone. Then we blend in real fruit juice and puree, add plant fibres and a sweetener, and can it at 330 ml in Kuldīga without pasteurising.
Green tea plus a kombucha culture, fermented until most of the sugar is gone.
Real fruit juice and fruit puree are blended into the finished kombucha.
Canned at 330 ml in Kuldīga, unpasteurised, with the culture still alive.
Step one: the tea
The base is green tea brewed with water. In Matcha & Passion Fruit the certificate names it as an infusion of Japanese matcha green tea powder instead.
Step two: the ferment
The brewed tea is lightly sweetened and given to the kombucha culture, which the certificates describe as water, green tea and a SCOBY. Over several days the culture works through the sugar and produces organic acids, carbon dioxide and a trace of alcohol. This is where the tartness and the fizz come from.
Step three: the blend
Fruit goes in after fermentation, not before, so the fruit character survives. The certificates print the percentage: pineapple juice 20 per cent, raspberry juice 12 per cent, rhubarb juice 12 per cent, mandarin juice 10 per cent, passion fruit juice 7 per cent, mango puree 6 per cent, ginger 4 per cent, pear puree 2.5 per cent. Plant fibres follow, from maize and chicory, and then the sweetener that finishes the balance.
Step four: the can
The drink is canned at 330 ml and never pasteurised, so the culture stays alive in the can. That is why the label asks for storage between +2 and +25 °C and gives a shelf life of 365 days.
Is kombucha vegan?
Yes. Rudy's Kombucha is made from water, green tea, a kombucha culture, fruit juice and puree, plant fibres and sweeteners. Nothing on the ingredient list comes from an animal, and the culture itself is bacteria and yeast. The Hard range lists no animal-derived ingredients on its label either.
The whole ingredient list is water, tea, culture, fruit, plant fibre and sweetener.
The kombucha culture is bacteria and yeast, not an animal product.
The fibres come from maize and chicory; the sweeteners are erythritol, xylitol and steviol glycosides.
What is on the list
A typical certificate reads: water, kombucha culture, fruit juice or puree, dietary fibre, sweeteners, green tea. Coconut & Pineapple adds coconut flakes 1 per cent, Raspberry & Basil adds fresh green basil leaves 1 per cent, Matcha & Passion Fruit adds fresh mint leaves. None of those come from an animal.
The culture
A SCOBY is a symbiotic culture of bacteria and yeast. Both are microorganisms, and neither counts as an animal ingredient. Honey, gelatine, dairy and egg appear nowhere in the range.
Hard Kombucha too
According to the can label, the Hard range is water, fruit puree, symbiotic culture, sweetener (erythritol), hops, tea and champagne yeast. Every one of those is plant-derived or microbial, so the label lists no animal-derived ingredient. We hold no separate certificate for the Hard range, so that is a reading of the label rather than a certification. It is an alcoholic drink at 4.5% ABV, sold to adults 18 and over (20 and over in Sweden and Lithuania).
Is Rudy's Kombucha kosher certified?
Yes. Rudy's Kombucha is kosher certified, parve, by BIR (Badatz Igud Rabbonim, Manchester). The certificate covers the ingredients and the production process at our brewery in Kuldīga, Latvia, and the BIR mark sits in the footer of this site. Need the certificate itself, or a check on a specific flavour? Write to woof@rudyskombucha.com.
Certified kosher and parve by BIR, Badatz Igud Rabbonim of Manchester; the BIR hechsher is in the footer of every page.
The certificate covers the ingredients, their suppliers and the brewing, fermentation and canning in Kuldīga.
Kosher, vegan and gluten free: nothing in the can comes from an animal and no cereal goes in.
What the certificate covers
A kosher certificate is issued by a rabbinical certification body after it has reviewed every ingredient and its supplier, checked how the product is made and inspected the site. For Rudy's Kombucha that means the green tea, fruit juices and purees, plant fibres, sweeteners and the kombucha culture, as well as the brewing, fermentation and canning at our brewery in Kuldīga. Parve means the product contains neither meat nor dairy.
Which products
The certificate is issued for Rudy's Kombucha. If you need the certificate document, or want to confirm a specific flavour or the Hard range, write to woof@rudyskombucha.com and we will send you the current paperwork.
Why is Rudy's Kombucha unpasteurised?
Pasteurising heats a drink until the living culture is gone. We leave ours in, so the kombucha keeps fermenting slowly in the can and keeps its tartness and fizz. That is also why the label asks you to store cans between +2 and +25 °C and drink them within the shelf life.
Pasteurising means heating the drink until the culture no longer lives.
Rudy's skips that step, so the kombucha in the can still contains living cultures.
The trade-off is real storage rules: +2 to +25 °C, 365 days of shelf life.
What pasteurising would change
Heat is the simple way to make a fermented drink shelf-stable: it stops the ferment and fixes the flavour in place. It also flattens the sharpness that fermentation builds, and it ends the culture. We would rather keep the drink as it comes out of the tank.
What living cultures means here
It means the bacteria and yeast that did the fermenting are still in the can. It does not mean we make any claim about what they do for you, and we do not. It is a description of the drink, nothing more.
What it asks of you
Two things. Store cans between +2 and +25 °C, out of direct sun. Drink them within the shelf life printed on the can, which is 365 days. A can left warm for a long time keeps fermenting, turns more sour and holds more pressure, so chill before you open.
Can I brew kombucha at home?
Yes, people do. You need a SCOBY, brewed tea, sugar, a clean glass jar and about a week at room temperature. Home brewing is hard to keep consistent, which is why we ferment to a fixed recipe in Kuldīga and hold an ingredients and quality certificate for every flavour.
Home kombucha needs a SCOBY, sweetened tea, a clean glass jar and time.
The hard part is consistency: temperature, time and sugar all move the result.
Our fermentation runs to a fixed recipe, with a certificate per flavour.
The basic method
Brew tea, dissolve sugar in it, let it cool, add a SCOBY and some liquid from a previous batch, cover the jar with cloth and leave it at room temperature for roughly seven to fourteen days. Taste as you go. The longer it runs, the more sugar disappears and the more sour it gets.
Why ours does not taste like a jar on a windowsill
Temperature, time, tea strength and the health of the culture all move the finished drink. A brewery controls those and blends the fruit in afterwards at a measured percentage, which is what makes one can taste like the last one. Every Rudy's flavour has an ingredients and quality certificate behind it.
If you would rather skip the jar
The Tasting Set is nine cans, one of each flavour, which is a faster way to find out what you actually like.
Rudy's Kombucha store homepage: https://rudyskombucha.com/ (Rudy's Brewing Co., independent kombucha brewery in Kuldīga, founded 2019; brewed without stabilisers or colours)
