What's this floating on my wort?

[Ninjatricky]

Hi all,
I'm relatively new to home brewing beer and have been experimenting with kitchen brewing using grain and spray malts. To save a bit of time on my latest brew I decided to try an extract kit. This came with spray malt and hop extract, which (according to the instructions) just required mixing with boiling water in the fermenter and then topping up with cold water. It's been very hot recently and the wort was still a bit warm to pitch my yeast, so I left it overnight to cool. On opening it the next day, it smelt a bit funny and had this floating on top (see pic).
Question: can anyone confirm what this is? (I assume it's mould) and although I've now chucked the batch, would anyone recommend a course of action that could have saved the batch?

 

[RPh_Guy]

It does look like mold.

Using a wort chiller is a good investment to help prevent contamination.

Welcome to HBT!

 

[myndflyte]

I was going to say yeast rafts but since you haven't pitched yeast, that might be mold. Did you sanitize your fermeter and everything?

 

[RPh_Guy]

The greenish-grey color also gives it away as mold.

 

[Ninjatricky]

I was going to say yeast rafts but since you haven't pitched yeast, that might be mold. Did you sanitize your fermeter and everything?

Yes I sanitized everything, but the starting gravity was too low, so between the multiple samples I took for hydrometer readings whilst trying to bump it up and then temperature readings, I could have introduced something. I didn't resanitize after each use, so it is possible the equipment touched something in the kitchen without me realizing - lesson learnt! I've made lots of wine and cider in the past and never had an issue, but then I've never faffed around as much as I did with this kit!

 

[Ninjatricky]

It does look like mold.

Using a wort chiller is a good investment to help prevent contamination.

Welcome to HBT!

Thanks for the advice, I'll look into that. The last batch of kitchen brew I made was three gallons and that took forever to cool down in a sink of ice water so this sounds like a very good investment!

 

[RPh_Guy]

The gravity should never be off when using malt extract... It was probably a measurement error from inadequate mixing

 

[Ninjatricky]

The gravity should never be off when using malt extract... It was probably a measurement error from inadequate mixing

I think I added too much water. The instructions were for a kit with liquid malt extract, but the supplier substituted it for a lesser amount of spray malt but didn't change the amount of water to add in the instructions.

 

[RPh_Guy]

I think I added too much water. The instructions were for a kit with liquid malt extract, but the supplier substituted it for a lesser amount of spray malt but didn't change the amount of water to add in the instructions.

That makes sense too.

Sorry you had to dump it.

BTW here's an article about chilling:
https://***************.com/wiki/Wort_chilling