The starter I mentioned previously in my other post has been going for 5
days now. It's extremely active, puffing to 2-3 times its size (I keep
mixing it, because a skin forms on the top). I've been taking out 1/2 c.
starter, and replacing it with 1/2 c. water and 1 c. flour. Just regular
flour, not the wheat flour that I used to start the culture.

It has some sour taste to it (the last time I stirred it, I tasted a bit of
it), and I was able to rise some bread with it (the bread had a really good
texture, but not a very good flavor, but I wasn't making it for the flavor,
I was making it to see if the starter could rise it). It wasn't a
super-good rise, but it rose about 1.5 times in 2.5 hours. I rose it
outside, like I usually do with when I make yeast products, as they tend to
be much more flavorful & have good texture when risen in the sun.

The sour taste isn't super sour, but it's getting there.

It also has a very fermented smell to it, and every time I mix it, it
releases a wonderful gassy aroma. Should I put it in the jar now, and
refrigerate it? Or, should I let it sit for another day/couple of days on
the counter?

The last time I made starter was in January, and it was a refrigerator
starter -- I cultured it in the refrigerator (again, I know that's
blasphemy).

I haven't been throwing out the 1/2 cup, I've been using it to make cookies,
biscuits, pancakes and whatnot -- anything that requires baking soda.

I've been using the same wire wisk to stir it, and the same cup, filled with
water. I just change the water every day so it doesn't get gunky.

I'm not worried about mold though, because mold doesn't grow where I live.
I can leave a loaf of bread sitting out on the counter for weeks and weeks,
and it won't get moldy; it will only dry out. And it takes literally months
for things to go bad in the refrigerator. Heck, I have the same apples in
there that I bought in March, and they're still edible.