Mold(?) in starter, toss it?

[JoppaFarms]

This is 0.5 oz of grain in a 1.035 starter solution to see what I could grow. Held at 100F for a few days. I'm assuming this is mold, it looks like it started on the two pieces of grain that stuck to the side of the flask at the waterline, and was exposed to the air in the flask. It smells...funky, not tart/sour, but also not like vomit. Waiting on the sample to cool so I can taste it.

So my question is, toss it? Try and fish the mold out somehow? I have a vial of lacto and brett on the way for a sour I have planning. I was just bored and trying to see what I could grow in the mean time.

 

[JoppaFarms]

The sample I pulled from the flask tastes fairly faintly clean sour, like lemony/citrusy sour and has a bready/grainy finish. Could I make up a "step-up" starter volume and drain/repitch into that to potentially save whatever I've got?

 

[JoppaFarms]

So against better judgment I kept 1 gallon of my pale ale aside and put a pint of this starter (sans mold) into a gallon jug with a couple peaches that I puréed. The mold was hard, like a rock, strange. We'll see what happens. The starter was kept on the countertop for a few days and got SUPER tart. We'll see what happens.

 

[BzurkoBrews]

I excited to hear what happens!

Sent from my iPhone using Home Brew

 

[JoppaFarms]

Me too! I figure since the mold was pretty isolated (both pieces were attached to pieces of grain that floated) and the pH had dropped (I'm guessing because of how tart it was) plus the lowered pH and the hops from the Pale Ale that MAAAAAYBE it's gonna be ok. It's a big guess, but it's only 1 gallon.

It's strange, when I pulled the sample from the flask after like 3 days at 100F it wasn't very tart at all. Then after 2 days of sitting on the counter at room temp it got SUPER tart, exactly the kind of sourness I was looking for. So we'll see how it turns out in a few weeks/months. Who knows, I'm in no rush with this experiment.

 

[JoppaFarms]

 

[JoppaFarms]

It's been 12 days since I transferred the "moldy" start to the 1 gallon carboy. I carefully poured the starter into a separate vessel to separate the moldy pieces from the wort. Then I added the meat of 2 peaches (didn't add the skin or pit) to a carboy, added the starter wort (about 1 pint) and filled the rest with finished pale ale (dry hopped). There has been slow and steady fermentation for the last 12 days, but it has started to slow now. There is definitely some of the original yeast in this as there has been a mini krausen a few times that I have swirled down (punch down of the fruit to prevent oxidizing). There is also some sediment at the bottom (mostly fruit but you can see a yeast layer of some kind). The starter had some sediment in it also, not sure what exactly grew but it was really tart and funky smelling when I moved it. I'll keep this post updated, even though it started about the mold in my starter, it may be a good example showing that you (maybe) can salvage certain starters if they go wrong.

My theory is that the lowered pH of the pale ale, along with the hops prevented the mold from reproducing and growing again. However, the hops may also have inhibited the grown/fermentation of any wild bugs I got from the grain (BeerSmith puts this at about 42 IBU). Good news is that the starter I used was SUPER tart, so even if the bug fermentation has been inhibited, hopefully the tartness from the starter carried over. This is all just a crazy experiment, so we'll see how it turns out in the end. I will probably wait another 2 weeks before taking a sample to see gravity and taste. All in all this will probably spend the next few months finishing.