We have a favorite chili recipe that we've been making for years.

Towards the end of cooking, I mix some masa with warm water so that
it's slightly creamy (not thick or pasty). I add this to the chili
for the last 20-30 minutes of cooking, and it adds a nice richness.

The last time I made it, when I added the masa/water mixture, it
immediately formed clumps. It never redissolved. I fished out as
many clumps as I could, but the finished product was bad, because
there were still lots of little clumps that were like eating dough.

Worst thing is, it was a triple batch for freezing, so it mocked me
for months to come.

I'm making chili again tomorrow. I hate to leave out the masa out of
fear, I really like the texture it adds.

What do you think went wrong the last time?