Storing/Reusing Starter Wort

[matt76]

I've made about 2.5L starter wort but I can only fit 1.5L in my stir jar.

1. Is it okay to wait until the first 1.5L has fermented out, let the yeast settle, pour off the liquor, add the final 1L to the stir jar and carry on fermenting/building the starter?

2. In the meantime, am I ok storing the spare 1L wort in the fridge for a few days or does it need to be frozen?

Cheers,

Matt

 

[Drunkula]

As long as it's capped and already been boiled I'd be fine with it - you could raise it to 70c for a minute and cool it if you're really worried.

 

[stz]

I would typically advise against reusing starter wort because it isn't worth the risk to save it. But that said I've bottled some boiling wort before with the intention to use later on at home once it had cooled down. I put it in the fridge and forgot about it. It was fine for a few months before I eventually threw it out, though if I wanted to I could have probably used it, if I was worried I could have reboiled it first.

 

[Drunkula]

I add hops teas to spent starter and prime and bottle it - it's genuinely better than most kits I've done. That's not hyperbolic tripe for a change.

 

[Hoppyland]

I'm with Drunkula. Surely there can be very little risk if you store the wort and then pasteurise it before re-using.

 

[PhilBrew]

Hi Matt

However you go preparing your starter wort, you need to recognise that doing this ...

... wait until the first 1.5L has fermented out, let the yeast settle, pour off the liquor, add the final 1L to the stir jar and carry on fermenting/building the starter?

... won't be building your starter ... if anything it may make a less viable colony of yeast to pitch

When you pitch yeast into wort, they'll reproduce (providing there's sufficient nutrients) until the colony is big enough to ferment all the wort ... but if the colony is already of a size where it can (already has) ferment more wort than it is being pitched into (like pitching the yeast from a 1.5ltr starter into 1 ltr of wort), then no reproduction happens, the yeast just get on with fermenting the wort, but there isn't enough food to feed all the colony and the overall viability of the colony is likely to be less than if you'd just grown them to a 1ltr starter in the first place

Are you particularly looking to grow a 2.5 ltr starter? Or are you just trying to use up the 2.5 ltts of starter wort you've made?

Cheers, PhilB

 

[matt76]

Thanks @PhilBrew for that concise explanation.

I think I worked out I actually needed a 2L starter but somehow ended up with 2.5L.

In the end I did not pitch the additional 1L as I reckoned this was probably more risky than possibly (but not definitely) slightly under pitching.

Looking at the yeast calcs again and given the uncertainty in the inputs I think I can get by with the 1.5L starter I made - or at any rate I'm comfortable with the risks!

 

[PhilBrew]

Hi Matt

FWIW, I think your logic is sound ... good luck with the brew :small

For next time you think you might need a starter greater than 1.5 lts ... or in case anyone else finds this thread through search ... you can always use an empty, and sterilised, 4pt milk carton or 2L pop bottle as a makeshift extra starter flask if you need one

You could have ... made your 2.5lts of starter wort and put 1.5 lts in your ("main") starter flask and the other 1ltr in your "overflow" ... you'd have then pitched 3/5 of your yeast into the main starter and 2/5 into your overflow, and put your main starter on your stir plate and left the overflow on a counter in the kitchen (or somewhere you go frequently) and given it a good swirl every so often, whenever you went past it and remembered to ... a swirled starter will produce "only" around 90% of a continuously stirred one, but pitching the yeast from both the main and the overflow would still have produced more than a 2 lts starter, without any risks from storing unfermented wort

Cheers, PhilB

 

[matt76]

I add hops teas to spent starter and prime and bottle it - it's genuinely better than most kits I've done. That's not hyperbolic tripe for a change.

Couple of things I'll add to this, both just for a laugh.....

1. Inspired by @Drunkula above I tried this, so now I have a litre of "something" conditioning in a plastic bottle - let's see what happens.....

2. After I pitched my yeast into my brew I still had this 1L spare starter wort kicking around. I figured what the heck, and chucked it into the stir jar with the few dregs, drips and drops of year left in the jar and stuck it back on the stir plate. There can't have been even 1/4 tsp yeast slurry there but even so, judging by the colour change the yeast has grown into a healthy pitchable amount. I'm not sure I'd actually dare using it in a brew but interesting to note how readily these little blighters will grow!