Chewy Caramel Popcorn Balls

I got this from the good old River mountain ward cookbook.  I think Corinne Barton submitted the recipe.  I have made them countless times.  They seem pretty fool proof since I haven't even messed them up once and EVERYONE loves them!

1 square of butter
1 can sweetened condensed milk
1 cup brown sugar (or a little more)
1 cup corn syrup
2 qts pop corn (This makes them pretty carmelly which is just the way I like them.  If you want them to be less rich, add more popcorn.)

Heat first four ingredients to boiling and boil to soft ball stage, stirring constantly. (It needs to continue bubbling, but turn down the heat slightly if it starts sputtering.  NO FUN getting hit with flying carmelly lava!)  I have never used a candy thermometer, so I don't know the temperature.(see below for my explanation of how I test it)  After it reaches the proper stage I pull it off the heat and let it cool for just a minute before pouring it over the corn.  Then I use two fold top baggies to cover my hands like gloves, and form them into balls.  (I have tried to use vinyl gloves, but the caramel sticks to them.  The baggies work best for me.  The caramel doesn't stick so its easier to form balls and they protect you ever so slightly from the heat.) You can let them cool a little if they are too hot.  But they are easier to form when at least warm, so don't wait too long.

To measure soft ball stage, I just use the old ice water method.  Have a bowl of ice water handy and put a couple of drips of caramel into the ice water.  Let it set for a few seconds to get cold and then feel it to tell how solid it is.  Basically soft ball stage is just what it says.  When cooled it should form into a soft ball.  You want it solid enough to hold up, but not hard as rock.  I actually make them differently based on the taste of those who I make them for.  My husband likes them a little more firm, and some others like them a little softer...  On my stove it takes about 12-13 minutes to get them to the right stage when I make a double batch.  It's a little longer of course if you make more.  The caramel also slowly darkens in color, that's another indication that it might be ready.  I usually make double batches, and I think that is ideal, but I have even quadrupled at times.  It takes a REALLY long time to get it to soft ball on a quadruple batch.  Just a couple more notes:  I usually use dark brown sugar for everything, because I love the richer flavor, but I don't notice much difference with these.  I also use more than a cup per batch.  I often just dump a 1 lb box in a double batch. (That adds approximately an extra 1/3 cup)