Kombucha!

When i arrived at Waag today two beautiful SCOBY’s were waiting for me.

On the right you see a normal kombucha SCOBY, but in the lighter jar on the left sits a jun tea SCOBY. I’ve never worked with a jun tea SCOBY before.

Jun tea is similar to kombucha, but made with honey instead of sugar. Since honey is antibacterial, and a SCOBY is mostly cellulose with yeast and bacteria, a normal SCOBY cannot handle honey. A jun SCOBY is resistant towards the antibacterial characteristics of honey and can ferment honey-based tea. I loosely followed this recipe for both jun and kombucha.

Preparing first batch

INGREDIENTS

Jun:

3L water

1L starter

15g Gunpowder green tea

320g honey

Kombucha:

5L water

1L starter

25g English Melange black tea

300g raw cane sugar

STEPS

1. First i sterilized the jars by giving them a good rinse with soap and filling them with boiling water. When the water cooled down i emptied the jars.

2. I made the tea by boiling 1/2 the water, dissolving the sugar, adding tealeaves and letting it sit for 10 minutes. For the jun i first waited until the water cooled down to 80* before adding honey and tea.

3. After removing the tealeaves i added the other 1/2 of the water. I waited until the water cooled down to around 30*. I poured the sweetened tea into the jar.

4. I added the SCOBY and closed the jar using paper and a rubber band.

Measuring

I measured the sugar content (Brix) and sourness (PH) on several days. There is a big time-gap because i had COVID. I Noticed the values stayed almost the same.

I used a plant-soil PH meter, which probably wasn’t suitable. On day 14 i used PH strips to measure, which gave better results.

X	Day 1	Day 2	Day 10	Day 14	Day 16
J Brix	7*	7*	7*	7*	6*
J PH	5.5	5.5	5.5	3.5	3.5
K Brix	6*	6*	6*	6*	6*
K PH	5.5	5.4	5.2	5	4.5

Results and bottling

On the 10th day the Jun looked really cloudy due to the yeast.

I tasted the jun on day 14 and it was already slightly too acidic. I bottled the jun in sterilized glass bottles and left them at room temperature for a second ferment. I forgot to at sugar so after two days there was no carbonation. I added sugar so i hope the jun won’t be to sour when enough carbonization is realized. I made new tea for the jun and refilled its jar.

I bottled the kombucha at day 16. It is not too acidic. I made new tea using a bit more sugar (starting Brix 7*) and added vinegar to the tea to lower the PH to stimulate a thicker scoby to form. (starting PH around 4)

JB1 = Jun tea before bottling

KB1 = Kombucha before bottling

KB2 (upper) = new kombucha tea before adding vinegar

KB2 (lower) = new kombucha tea after adding vinegar

Recommendations after discussing

[Dinner with Darwin

Bill Bryson - Geschiedenis van de keuken

Tasting History]