first larger batch

[kitobi]

hi all.

been doing 1 gallon batches of kombucha just fine with Jun as well for a few weeks, both been working well.
I recently got 2x large 2.5 gallon jars to make each in for a continuous brew system and have hit a snag.

I have stainless steel taps at the bottom to sample/draw off the liquid and have been sampling for 3-4 days on this 12 day batch, its still super sweet from the bottom, I have a massive new scoby now growing so I though it try to take a sample from the top and its 100% vinegar. so the top of the brew and the bottom are total opposites. I know your not supposed to stir the brew but how can I blend the batch to get a better account of how its tasting?

 

[stout12]

I do batch brewing rather than continuous. I reserve my starter liquid from the top without stirring to favour the bacteria and prevent the yeast sediment building up in future batches. Once I have done this I stir the remaining kombucha up so all the yeast sediment is evenly distributed in the bottles.

Other than this I don’t see any issue stirring it, however I do normally leave it be until it is ready to bottle. Keep in mind that stirring it will disrupt the new Pellicle growth but this won’t be an issue. Most of the bacteria & yeast are actually in the liquid anyway and the pellicle is just a cellulose mat which some of the bacteria and yeast happen to hide in/on.

How long does it normally take when you start brewing until it is ready to bottle/drink?
A larger volume of liquid may take slightly longer to ferment and colder temperatures will definitely slow things down.

Hopefully others with more experience can add there thoughts. Good luck!

 

[kitobi]

Hi stout. Thank you for your advice. This is the first time I have brewed this size so I don't know how long it should be. I tried last night to remove 4 ltrs from the bottom and poured it over the scoby to see if it dissolved the vinegar level and combined it all but it didn't seem to work so well. It's now 13 days on first ferment the top is super sour and the bottom is sweet.

 

[stout12]

1) In previous batches how long did you ferment for?

2) Also what are the temperatures like? Has it changed a lot?

3) Are you using any heating mat or device? If so where is it placed? (I.e. on bottom, side near bottom, side near top)


According to the Big Book of Kombucha - approximate brew cycle:

1/2 gallon = 3-7 days
1 gallon = 7-21 days
2.5 gallon = 10-28 days
5 gallons = 18-42 days

I have not yet brewed more than 1 Gallon so I don’t have personal experience with larger batch sizes but it may just need more time.

It would be expected that the top may be slightly more tart as the bacteria which convert the alcohol to acids are more concentrated at the top near the oxygen but it is strange that mixing it has not distributed and evened the flavour out and that there is such a big difference between sweet at bottom and tart at top. However the bigger the volume of liquid, especially if the vessel is deep the longer it can take as the bacteria require the oxygen at the surface of the liquid.

5) Is the opening at the top of the vessel large? Maybe you could upload a photo of the vessel?

6) Would you say that the liquid at the bottom tastes about as sweet as the original sweet tea? Is the sugar fully dissolved in the liquid?

Sorry to ask so many questions but hopefully it can help me or someone else to help you.

In the meantime I imagine the best thing to do is keep tasting each day. Time might be all it needs.

 

[kitobi]

hiya stout, no worries thanks for the reply

I tied it today and bottled approx. 2 litres to flavour and carbonate. leaving approx. 2/3rd of the Jun behind
it took best part of 14 days, but I have made a few adjustments since.

the previous 1 gallon batches took approx. 8-9 days with no heat, but thinking back the weather was colder and the central heating was on much more, so maybe the ambient air temperature was higher.

I have since dug out a old brew belt and a spare inkbird 308 controller which helped a lot but the belt didn't make great contact, so I have now got them on a seedling heat mat set to 24c which is the sweet spot for Jun tea. and its holding its temp within a half a degree day and night.

the whole vessel is 8 inches wide and the top opening is 6 inches

the bottom was as sweet as freshly brewed tea for almost the entire brew but the top was like apple cider vinegar.

I guess as there was little residual heat especially at night the brew was much slower that anticipated, now its at a constant 24c it seems to have sped up and bubbles are now visible, the pellicle is growing nicely as it had 3x 4 inch ones added with a half gallon on pre made Jun, I now have a pellicle forming that's about a quarter inch thick and 8 inches wide.

on reflection it was too cold which slowed everything down to a snails pace, the smaller vessels would have warmed up much faster just being in a warm room which is why they still seemed to be ok.