There really isn't anything in beer that can make you sick.
QUOTE]
True there's nothing in beer that can make you sick, but there are lots of things that can grow in unfermented wort that can make you sick.
Zymurgy had an article about a year ago for a fairly simple, sour mash process that I used for a sour blonde ale and it worked well. Take a hand full of base malt grain, and throw it in a pint/quart of starter wort (I used a pint of canned wort, which is sterile). Keep it at ~100 degrees for 3 -6 days - this is important to allow the lacto to take over and not have other bad bugs win. I kept it warm using a reptile heating stone in a small cooler. After a few days it should have a sour green apple smell - no garbage dump or vomit smell at all.
Then, mash your grain recipe as you normally would, sparge and heat to a boil for 10 minutes or so to kill any bad bugs. Cool it to around 110 degrees and drain your wort into a 5 gal contractor water cooler until it's full all the way to the top to minimize any air exposure. While it drains, add your lacto starter to it. Put the top on the cooler and cover with a sleeping bag and keep it somewhere warm for 12 -24 hours. Then drain back into your boil kettle and do a normal 60 minute boil, which will kill off any bugs, while adding your hops and whatever is in the recipe. Ferment with a normal sach yeast.
Sour mash will give you a tangy, lactic sourness similar to a Berliner Weiss. It's quite one dimensional compared to a lambic or flanders brew, but it works well in an already complex beer (saison, dark belgian ale, etc), or for a BW. A friend made a maple brown ale and a spiced pumkin beer with the sour mash and they turned out fantastic. My sour blonde was pretty one dimensional so I've added some fruit to it along with some brett to try to add some depth and complexity to it.
Edit - I actually mashed 6 gallon of wort for my blonde ale. I drained 1 gallon into a PET plastic jug and put it in the fridge for the night, and soured the 5 gallons in the contractor cooler. The next day I boiled all 6 gallons of wort. This way you finish with a 5 gal batch.
