For the past 2 or 3 years I've been making a tomatillo salsa from scratch and it will usually last several weeks in screw-tight jars in the fridge. Sometimes it will get a bit acidic towards the end.
This last batch I made has developed a white fuzzy mold within 10 days or so. No idea why, but maybe someone here can help.
The recipe involves roasted tomatillos, onions, garlic and jalapeno peppers, cooling them down and then pulsing them in a Cuisinart with cilantro, a little salt, cumin, lime juice, and hot sauce (to taste). Pretty basic..... and always the same. I'm making a new batch tomorrow and would appreciate any ideas. I've never needed to go through the whole nine yards of Ball jars and steam baths for this and would really rather not have to start now.