1) Will pickle crisp affect flavor?

Yes, it might. Calcium chloride is a salt, so it can taste "salty" depending on your taste buds. Regular salt is sodium chloride, which we all know under the common name of "salt". Some people can detect a chalky taste from Pickle Crisp which would be the calcium in it (ever eat Tums? - those are calcium carbonate and taste, to me, like blackboard chalk). Again, depends on the sensitivity of taste buds.

As an example, if I order a margarita, I cannot tolerate the lime (fruit) and salt on the rim. But run an orange or a lemon over it instead and dip it in the salt, I love it. I also do not like salt on sliced tomatoes. I think it's hideous. DH salts his liberally. It may be your taste buds reacting to the type and flavor of the acid/type of salt combo.

Note: I tend to cut the sodium type salt in recipes where I'm using Pickle Crisp where it is safe to do so.

2) How long does it take pickle crisp to work?

I honestly can't answer that one, because I've never opened a jar of anything where I've used Pickle Crisp (tomatoes, pickled peppers, etc.) before it has been on the shelf for a least a month or 6 weeks. And (so far, knock on wood), I don't detect any chemical flavor or lack of crispness. Pickling lime is calcium hydroxide, so it reacts differently (and likely faster) than calcium chloride.

3) Does the thickness of the syrup in this recipe interfere with how pickle crisp works?

Long term, it shouldn't. My guess is the Pickle Crisp didn't completely have time to do its chemical reaction stuff before you popped the lid and tasted.

Probably more than you wanted to know...

Hey, I asked the question! I certainly want to know as much as you've got to tell me! Thanks for your response.

I will just have to wait patiently and see if the flavor improves and the crispness develops. *stares at jars and taps foot*

Calcium chloride has a very penetrating saltiness compared to sodium chloride, along with a tinge of bitterness. Is this the acrid taste you're referring to?

I bit the bullet and mixed the amount of calcium chloride I put in each jar (about 1/8 teaspoon) into a little bit of water about the volume of syrup in the jars.

Blech! The calcium chloride is definitely what I'm tasting and it is interacting with another flavor (I suspect the lime juice) to make a long-lasting aftertaste.

I briefly considered mixing up another batch of syrup and boiling the pickles in that to try to reduce the amount in the finished product. Of course, they would be refrigerator pickles at that point. However, I suspect that will just be a waste of sugar and vinegar.

I will put the pickles up on the shelf and see if several weeks of sitting will mellow it. Such a disappointment!

Just add 1 oak leaf and 1 grape leaf to each jar of pickles for crispness. I make salt water pickles. Just opened a jar from August 2020 and these are super crispy!