Is this 2nd fermentation safe?

I just started trying out water kefir.  I successfully did the first ferment and for the second ferment, added organic tart cherry juice, some organic cane sugar, 8oz of my 1st fermentation batch, RO water and some drops of concentrace.

It’s been two days and the following picture is what I see.

Keep in mind that I didn’t fully close my mason jar.  I used a banded lid with filter paper as a barrier.

How do I know if I’ve grown something beneficial vs pathogenic?  I certainly don’t want to create a bacterial or yeast imbalance in my system.

probably kahm yeast-  not going to hurt you (it looks whitish and... scaly? dry? will break into little "plaques" and float on top) but can affect the taste.
Sites for kombucha and etc suggest making it more acidic to avoid kahm yeast, I imagine for water kefir it would be similar. Add a slice of lemon, maybe. It sounds like you've maybe got a lot of sugar going on, which yeast enjoys.

What Tereza said. It looks like the yeasts have gotten a little overexcited there! It's unlikely to be harmful, but it's not appealing, either.

You don't usually need extra sugar in the secondary ferment, especially when also adding juice concentrate. The microorganisms will work fine with the sugar and lactose left in the liquid after the first ferment. And there's no need to add more minerals, either.

I often used to do my secondary ferment with just the fluid from the first fermentation, or add nothing more than a slice of lemon or fresh ginger.

Jane Mulberry wrote:I often used to do my secondary ferment with just the fluid from the first fermentation, or add nothing more than a slice of lemon or fresh ginger.

This is such an important point- secondary fermentation (at least with booch, i haven't done water kefir in years and don't remember if it's quite the same) requires minimal sugar and is a great chance to add extra flavor with herbs or aromatics (ginger, lemon verbena, etc)- a slice or two of ginger or a few raisins are enough.
if you want juice or sweetness, mix it in when you're serving. that way your cherry juice, for example, stays flavorful, your secondary brew is pleasantly fizzy, and you also have no hurry to drink it all.

Thank you all for your replies.  It’s all very reassuring.

Prior to reading these responses, I had tried finding other answers and did stumble upon Kahm yeast but wasn’t completely convinced until now.  I have read some conflicting info on Kahm with the majority saying the yeast were innocuous while a modicum of other places claimed it was beneficial with probiotic implications.  Some websites related that by using more acidic juices or additives in the second fermentation like citrus juices or peels, that would deter Kahm growth.

The main reason why I would use fruit juices in my second fermentation is to reduce my overall sugar consumption since the bacteria & yeast would (hopefully) take care of what was naturally in the juice.  This would theoretically leave all the good antioxidants behind for consumption.  I don’t know if this thought is correct though.

If I capped my fermentation with a solid lid, would that have repressed Kahm growth since I’m assuming they are obligate aerobic organisms?  I don’t like carbonation which is why I opted to cover with filter paper instead.   So with that in mind, I have a few more questions —

1.  Does the presence or absence of oxygen in the 2nd ferment affect the quality of replicating bacteria & yeast that came from the 1st kefir fermentation and therefore the quality of water kefir produced?  Are all bacteria and yeast in a water kefir facultive anaerobes or am I risking killing obligate anaerobes?

2.  I’ve seen instructions about using coconut water with the kefir grains, but can coconut water be used as a sugar source in the second ferment?  Does it contain the right type of sugars for the bacteria & yeast to thrive?

3. Does the second ferment need to be kept in the dark?  I still couldn’t find a direct answer as to why the initial ferment needed darkness to thrive.

Anyhow, thanks again for your replies.  I hope these questions aren’t to much of a hassle.

There are a lot of questions here, but i can answer two, about citrus and closed containers. I make my own limonene cleaner by steeping citrus peels in vinegar for a few months. Water bag sealed, so no oxygen. When it's done it's covered in kahm yeast. So i have my doubts about a slice of lemon solving it.
I also make a lot of lactic acid pickles, Asian style, and kahm yeast is almost always present, the traditional wisdom is to not worry about it.
You raise a good question about whether the good stuff you want is still present in your final brew or is degraded during fermentation. I think you'll need a chemist to know for sure, but i think I'd just add anything like that at the end after fermentation.

What Terza said, again!

I didn't get Kahm yeast in my water kefir. (i was making it for several year, only stopped because I was away from home for a while and unable to look after it). I did get Kahm yeast in a ferment to make vinegar, and it didn't die off even when the acid content was high.

I did my primary ferment open, and my secondary ferments were sometimes open, sometimes closed, depending whether I wanted fizz.

Your rationale for adding the juice to the second ferment makes sense, the organisms should be able to consume some of the sugars. But my guess is that the yeasts are better adapted to dealing with fructose, while the bacteria are better adapted to sucrose and lactose. I would expect to see some yeast overgrowth in that case. Coconut water - yes, water kefir grains can ferment it, but they'll die off quickly because the sugars aren't right for them. I tried some once with spare grains, but the taste wasn't for me!

There are a few possible issues with your ferments -
1. your primary ferment isn't fully active yet. I always threw out the first batch with new grains or stored grains (freezer of dehydrated) because it never tasted right. I think the bacteria take longer to get established than the yeasts;
2. there was too much sugar in the second ferment, you shouldn't need to add extra, especially if using fruit;
3. there were too many minerals, both in the first and second ferments.

Keep trying, I'm sure you will find what works for you and your grains!

Tereza Okava wrote:.... I make my own limonene cleaner by steeping citrus peels in vinegar for a few months. Water bag sealed, so no oxygen.

Have you posted this recipe anywhere? Would love to try it!

Mercy Pergande wrote:

Tereza Okava wrote:.... I make my own limonene cleaner by steeping citrus peels in vinegar for a few months. Water bag sealed, so no oxygen.

Have you posted this recipe anywhere? Would love to try it!

Mercy, it's that straightforward-- i fill up a gallon jar with as many citrus peels as i can cram in, cover with white vinegar and a plastic bag full of water on top to make it airtight, sits in the dark for some months and then strain it out, it's ready to go. I love to use it to clean the kitchen and bathroom.