Will any wort do?

[maceyboy]

As a newbie to using liquid yeast (this may seem a ridiculous question to you more experienced brewers), i was hoping to split my recently aquired Wyeast Czech Pilsner liquid culture using Jim's method. Does it matter what wort I use to make my starters, eg.does using a particular spraymalt etc. have any adverse effect on a yeast that will be then pitched into a lager wort with a different characteristic. I obviously assume i would need to initially propagate my yeast under conditions appropiate for a lager yeast.
Hope this makes sense.

[Vossy1]

I asked the same question recently as my starter made up 10% volume of the final beer. The answer seemed to be that it would make little difference to the final beer. I used light spray malt for mine as it's all I had.

[maceyboy]

Thanks Vossy, I had a feeling that might be the case, I was just curious as to whether the yeast mutates in response to it's specific nutrient, and if so, if it had any affect.

[Vossy1]

I was more worried about the taste.
If somebody put 10% earl grey in my pg tips brew I'd know the difference

[Aleman]

Ideally you would use a similar wort for your starters as for you main brew.

I use a pale wort for all my starters, as adding pale wort to a dark beer is not noticeable . . . Adding a dark wort to a pale beer IS!.

That said, I make my starter worts up to around 1.010-1.012, as I want to grow yeast rapidly and above 1.012 yeast never respire aerobically despite the level of O2. This means that my 5L starter significantly dilutes my beer wort, and therefor I allow it to settle out, decant off the liquid on brew day and add a quantity of wort taken from 1/2 way through the boil (And cooled!). A stir plate and pumped sterile air ensures the starter is working well when the main wort is cooled and ready to be pitched

[DRB]

I use beer kit enhancer for my starters works a treat and cheaper than spraymalt.

[steve_flack]

That said, I make my starter worts up to around 1.010-1.012, as I want to grow yeast rapidly and above 1.012 yeast never respire aerobically despite the level of O2.

Wow...that's weak. I've heard 1.030 is what you should aim at unless you're growing from a really old yeast or haven't got much (like off a slant). 1.030 is about 1g of DME per 10ml of water.

Doing starters at 1.015 would save a bit of DME.

[Aleman]

That said, I make my starter worts up to around 1.010-1.012

Wow...that's weak. I've heard 1.030 is what you should aim at

If the concentration of sugars in the wort is above 4%, the Crabtree Effect kicks in, and even though there is plenty of oxygen the yeast kick into anaerobic respiration|(*), which I am sure you know is very inefficient when compared to aerobic respiration. (6 time less in terms of ATP production???) From what I recall of this discussion on the HBD a 4% solution is around 1.012.

Having changed to this regime, I'm seeing the same growth in my starters, that I used to get with 1.040 but in a 1/4 of the time.

(*) So why do we aerate or worts? Well thats so that the yeast can build high levels of Sterols so that they can reproduce and build cell membranes, if you under oxygenate your wort then you prevent full yeast growth, and potentially end up with stressed yeast leading to poor/incomplete fermentations.

[bandit]

That sounds like a george fix answer

[Aleman]

That sounds like a george fix answer

I don't think I've seen it in POBS or AOBT, of course it might very well have been said on HBD when he was posting there.

In all honesty I am basing my starter process on the contribution of a large number of brewers who post to the HBD (Or did up to a couple of years ago) The collective knowledge of some of that crowd never ceases to amaze me.
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Of course you also need the ability to actually read what is said there and decide if it is bullsh*te or not. However having had access to MB&S, Narziss et al, JIBS, and training in a biochemistry background I can read the quoted papers/journals and make my own mind up.

If that fails its only a starter, and you can always do another step up if required SO its more than worth a try, especially if you have much of the required equipment anyway