TASK DEFINITION: Given the background description of some cooking related query, summarize the question into a title
PROBLEM: I have an open bottle of lemon juice that I've been keeping in the fridge. I just took it out to dress a salad and it fizzed like soda when I opened the bottle and smells like... took me a minute to place it... yeast. What's going on? Should I throw it out?

SOLUTION: Why is my lemon juice fizzing and smelling like yeast?

PROBLEM: Today I sauteed a quarter cup mushrooms in 3 tbsp butter and added 250ml cream. Everything was set for me to add the ricotta and finish the Alfredo, but it only partly melted. Beyond a certain point, there were some "cheese crumbs" that no amount of heat could dissolve, thus robbing me of a velvety textured Alfredo.I have successfully made Alfredo with ricotta cheese before. Is there any reason as to why the ricotta did not completely melt? The ricotta package was only opened a few days, so it couldn't have gone bad.

SOLUTION: Why did my ricotta cheese did not completely melt in the Alfredo?

PROBLEM: When looking for a blowtorch for the kitchen, you can buy some reasonably expensive tools. When looking for a blowtorch for plumbing, you can buy some reasonably cheap tools.The price is different. The look is different. The principle is the same. I guess the gas is the same.Why pay more? Is there a health issue? Is the kitchen blowtorch more precise?

SOLUTION:
Blowtorch - hardware store vs kitchen store. Is there a difference?