Given the background description of some cooking related query, summarize the question into a title

Q: Is white vinegar, aka the stuff just labelled as "vinegar" in the US and which I use for cleaning my kettle, the same as "White wine vinegar", which I have purchased on accident a time or two? If not, what is white vinegar made of?

A: Is white vinegar the same as White Wine vinegar?
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Q: Today I bought a 2 oz (56.7 grams) bottle of Bay Leaves. The "best use by" date is 01/2015. I've read that spices and herbs go "off" after a year or so, depending. Can I believe the 2015 date on these bay leaves?

A: "Best by date" true for bay leaves?
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Q: I've been making freezer burritos and eating them for lunches this week. The first batch I made microwave beautifully: just 45 seconds and they're hot all the way through. They were layered with rice, beans, and corn, nothing else (I don't eat cheese and I wanted them to be non-spicy so I can eat them when I'm feeling unwell). The second batch replace the corn with ground beef, cooked and seasoned. The exact same beans, the same rice made the same way. They're smaller, due to using a different package of tortillas; after almost 2 minutes of heating in the same microwave, the meat burrito I had brought still had cold spots in the middle. What causes this? Can I avoid it somehow? Should I mix the ingredients instead of layering?

A:
Why do my meat burritos not heat well?
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