Explosive Wort?!

[Tetsuo1981]

Hi all

Have been trying to grow some yeast for a Stella Artois clone recipe using their unfiltered beer. I made up 2ltr of wort using 500g german pilsner malt and 1/4 tsp of yeast nutrient (using bottled spring water). This went fine and I cooled it down with an ice bath to room temp. I filled 2 X 1 ltr swing tops to store the wort as I ramp up m starter. Started with 500ml and left it on stir plate for 3 days. So had 500ml left in a bottle in dark storage. I opened this today to feed my started and the lid went with an almighty pop. Didn't smell dreadful but I've got a horrible feeling that's something has occured. Any thoughts and ideas would be helpful.

Cheers

 

[Agentgonzo]

There is a chance something got in there and has started fermenting it. Things you could do:

• Take a gravity reading of it to see if it still has all its sugar
• Have a decent sniff of it
• Have a taste of it

If it still tastes, smells and has the OG of your original wort, then I would say give it a quick boil again to kill off anything that has been in it, then use it as you intended.

 

[Tetsuo1981]

There is a chance something got in there and has started fermenting it. Things you could do:

• Take a gravity reading of it to see if it still has all its sugar
• Have a decent sniff of it
• Have a taste of it

If it still tastes, smells and has the OG of your original wort, then I would say give it a quick boil again to kill off anything that has been in it, then use it as you intended.

Hydrometer buried under the stairs but a quick smell put me right off. Almost metallic to it. That and the sheer pop of the bottle made me think like you, something has done something fermentation-wise. Nuts. Oh well nothing ventured, nothing gained. Off to the ships for some DME and more unfiltered Stella to use.

 

[Agentgonzo]

Wort is an excellent growth medium for a lot of things. We can get away with sanitising (not sterilising) wort and fermenters because we introduce a lot of yeast into it straight away. The yeast can out-compete any remaining nasties in the wort/fermenter, and the alcohol that it produces does a pretty good job of killing off most other things.

If you don't put yeast into your wort straight away, then any of the following could happen:

• Your boil didn't kill off every living thing in your wort, and so the remaining ones start to grow quickly in your wort.
• You didn't kill off every living thing in the bottle you used to store your wort, and they bred forth and multiplied
• Any wild yeast and bacteria that is floating around in the air got into your wort as you transferred it into the bottles, where upon it had a party and started to grow and eat your beer

People have successfully boiled and stored wort... normally in the freezer (be careful freezing liquid in glass jars, as it can expand and break the container) so that any nasties in the wort grow at a much slower rate

 

[Agentgonzo]

Off to the ships for ... more unfiltered Stella to use.

Oh the hardships

 

[Tetsuo1981]

Your boil didn't kill off every living thing in your wort, and so the remaining ones start to grow quickly in your wort

Definitely not the case, it was going like the clappers for about 20 mins, even the wife said about it (is that safe???)

Any wild yeast and bacteria that is floating around in the air got into your wort as you transferred it into the bottles, where upon it had a party and started to grow and eat your beer

Thought about this and whilst not disagreeing at all, I've never had issues before but this leads into the next bit

You didn't kill off every living thing in the bottle you used to store your wort, and they bred forth and multiplied

This is where I think it went wrong (and the wild yeast bit mentioned above). I gave my bottles a good scrub and used Wilko bruclense (think that's how it's spelled), rinsed them and used chemsan I diluted with spring water. Only thing is my chemsan is quite old and the water went cloudy. Maybe time for some new chemsan and different cleaning gear.

Oh the hardships

Funny my Dad said exactly the same thing when I told him!!!

 

[Agentgonzo]

Cloudy chemsan sounds like it was a probable cause... But even if you did all of that perfectly, you'll only have sanitised the wort. It won't be sterile. There will still be stuff living in it that will feed on the wort.

 

[Tetsuo1981]

It won't be sterile. There will still be stuff living in it that will feed on the wort

Agreed. Need to thoroughly clean and sterilise everything before attempting again. Going to ditch the chemsan and use my old sanitizer once it's all clean, it's never let me down before

 

[An Ankoù]

Recommend you always make a fresh batch of culture medium (wort) immediately before you intend using it.

 

[foxy]

Hi all

Have been trying to grow some yeast for a Stella Artois clone recipe using their unfiltered beer. I made up 2ltr of wort using 500g german pilsner malt and 1/4 tsp of yeast nutrient (using bottled spring water). This went fine and I cooled it down with an ice bath to room temp. I filled 2 X 1 ltr swing tops to store the wort as I ramp up m starter. Started with 500ml and left it on stir plate for 3 days. So had 500ml left in a bottle in dark storage. I opened this today to feed my started and the lid went with an almighty pop. Didn't smell dreadful but I've got a horrible feeling that's something has occured. Any thoughts and ideas would be helpful.

Cheers

Get yourself some 1 litre Passata bottles, at the end of each brew day tip what is left in the kettle into a jug, I use a 5 litre jug and put into the fridge, let it settle and pour the clear wort into a saucepan. Bring up to boil and pour into the bottle. I get almost 1.5 to 2 litres of clear wort but only use 1 litre. Store anywhere you like, doesn't have to go into a fridge and use them for starters.

 

[DocAnna]

Just to add that @foxy has the right idea. The only way you are going to be able to store wort is if you bottle it straight after the boil. Starsan and chemsan just won't work, cloudy or not is irrelevant, they will never sterilise the bottles adequately for storage of culture medium (aka wort) at anything other than deep freeze temperature. This is the same principle when making jam (which I do a fair bit of). The standard method is to heat the jars /bottles in an oven. Jam jars or other sauce bottles as above are needed, you can also use kilner jars, though these need the seals soaked in boiling water. My approach to the jars for storing yeast from starters which is the same is to rinse them and their lids in chemsan and then bake for about 10-20 min at 160 deg C. Leave them upside down on the tray, they should be damp/wet when they go in the oven.
https://www.bbcgoodfood.com/videos/techniques/how-sterilise-jars-video
Even this isn't perfect, you need an autoclave, or facility for gamma radiation or EtO to properly sterilise something - which oddly enough, isn't quite at homebrew level - happy for @The-Engineer-That-Brews to now correct me if he has a home autoclave .