yeast starter time??

is 30 hours enough time to prepare a yeast starter, let it ferment out and then crash cool it, decant it and pitch it???? wasn't able to buy DME today!!!! sucks

thanks ahead!!!!!

How big is the starter? If it's a 1 or 1.5 liter, I've made them 11pm the night before, pitch the whole thing 12-14hrs later.

Also depends heavily on the yeast. Once it's done fermenting the starter wort, a yeast like Wy1968 will floc out very quickly without any crash cooling - very convenient. Some of the less flocculent yeasts may take 2-3 days or more even when crash cooled. Like the previous poster noted, if the volume is less than 5% of the total batch, just pitch it all. And if you're really in a pinch, just ignore that rule - you're probably not going to notice unless you have something like a 1+ gallon starter and try to rush your main fermentation too. I'd be more concerned about trying to rush the starter, decanting off the less flocculent yeast thus having an impact on main batch attenuation.

I am using wlp300 so I hope it flocculates fast!! Since i am brewing a hefe I don't want any of the starter beer to ruin the flavor of the beer. It's a 4 gallon batch and I am going to use a 1 liter starter.
Will i have enough time to ferment it completely plus cold crash it???

With the low flocculation I'd say no. I'd just grow it up and pitch the whole thing. 1L is only 1/15 the volume of your recipe so I'd be surprised if you could taste the difference.

You might want to pich it as an active starter. The worst thing you can do is to cool a starter before the yeast by itself goes into dormancy, so they will not be able to build up their glycogen reserves.