I've recently started to dabble in brewing sour beers. Right now I have one house culture going that I built up from dregs from some of my favorite sours (Gueuze Girardin, Gueuze Fond Tradition, and Lost Abbey Red Poppy). I'm just starting to fill up my pipeline of sours now, so it will still be a little while before I have some results to share.
I've heard a few podcasts recently discuss the production of lambic wort. Traditionally, a turbid mash process is followed to produce a starchy, dextrinous wort for the lambic. This ensures that the Brettanomyces will have food to work its magic over the long haul after the other microbes have consumed the simple sugars in the wort. The turbid mash is a rather lengthy process, but given the high enzymatic content of modern malt there are few other options to produce the type of wort you're looking for.
But, to coin a phrase, "Ain't nobody got time for that!". I've heard of other ways around this. Some brewers add flour. Others use a short, high-temperature mash. I haven't tried either, and while they probably get you in the ballpark, I have another approach that I think will get me the results that I'm looking for..
Lambic wort is typically just pilsner malt and unmalted wheat. To get the dextrins, I'm going to do a short, high mash (162F) on the pilsner malt portion of the grain bill. To get the starch, I'm going to steep some flaked wheat separately. After the wheat steeps, I'm going to raise the temp on that fraction of the wort to the 190F ballpark. Once the pilsner mash is done, that will be run off into the wheat wort. This will bring the mash above mashout temps a lot quicker than if I were going to heat the whole thing directly. Hopefully this will lock in the dextrin and starch content by rapidly denaturing any enzymes left in the mash. This will be followed by a short boil just to get about 8-10 IBU's from my hop addition.
If everything goes as planned, then I'll have a batch of lambic wort ready to go in almost as little time as it would take for a batch of extract brew. I'll keep you posted on my results.