Given a paragraph about cooking, and a set of conversational question answers about the paragraph, generate a relevant question to the topic of the paragraph. The paragraph has the prefix 'CONTEXT:'. Each conversation question has a prefix `Q:` followed by the answer prefix `A:`.

[Q]: CONTEXT: The sugar is mostly just for flavor. I use sugar when making pickled beets and eggs, but don't use it in my dill pickles or pickled peppers and onions. It just depends on if you are trying for a sour, sweet and sour, or sweet pickle (note that there is no vinegar in many fruit pickles).Before you decide to run off and leave out the vinegar, however, I would note that for pickling safety purposes there has to be enough acid to keep botulism causing bacteria from forming and peppers are a low acid vegetable. If you wanted to eliminate the vinegar, you'd have to move to pressure canning.  <sep>  Q: What's the purpose of sugar in a pickling solution? A: The sugar is mostly just for flavor 
[A]: Does is affect the preservative qualities?


[Q]: CONTEXT: Marshmallows expand so much because the water in them becomes steam, and gas takes up a LOT more volume than liquid. Specifically, 1 mL of water becomes ~1.36 LITERS of vapor, before it gets heated further. That's 1000-fold expansion, before you add additional expansion as the gas is heated. Marshmallows don't have all that much water content, but when it's trapped in a stretchy gelatin matrix that holds gas readily, it only takes a bit to blow the whole thing up like a balloon.You are correct that the gas expansion on its own is insufficient; unless I've badly muddled my calculations, gas expansion from 20C to ~150C (caramelization temperature) will increase the gas volume by under 50%.  <sep>  Q: Why do marshmallows poof up so huge when put in the microwave? A: Marshmallows expand so much because the water in them becomes steam, and gas takes up a LOT more volume than liquid  Q: Is the water the only component, or are there others? A: Marshmallows don't have all that much water content, but when it's trapped in a stretchy gelatin matrix that holds gas readily  Q: What else can you tell me about the science of it? A: the gas expansion on its own is insufficient; unless I've badly muddled my calculations, gas expansion from 20C to ~150C (caramelization temperature) will increase the gas volume by under 50 
[A]: Can the marshmallow caramelize in the microwave?


[Q]: CONTEXT: Yes, you can detect the difference. How much of a difference will depend on the quality of both the imitation and of the real thing.That said, it's difficult if not impossible for me to pick out the differences in baked goods. So I keep both around, and use the (much cheaper) imitation stuff for baking, and the real stuff for sauces, icing, custards, milkshakes, etc.Incidentally... In a pinch, bourbon makes a half-decent substitute for vanilla.  <sep>  Q: What is the functional difference between imitation vanilla and true vanilla extract? A: it's difficult if not impossible for me to pick out the differences in baked goods 
[A]:
Why is it difficult? One is chemically made and the other is an extract