More on squeezing and storing citrus juice.

One possible explanation as to why a slight (4-hour) aging on fresh hand-squeezed juice may be preferable to just-squeezed.

Enzymatic Bittering. My favorite explanation for the decrease in tartness of aged lime juice. Bartender Stephen Shellenberger explained to me that all citrus fruits contain an enzyme that will produce the bitter compound limonin in the hours immediately after juicing. As we’ve covered before, a very small amount of bitter flavor can mildly suppress sourness.

Science. Part of successful cocktails. 

An appropriately named article.

Fresh Lime Juice: WTF?

I don't want to bury the lede:

The overwhelming favorite was the hand-squeezed lime juice that was 4 hours old. The distant second place was 4 hour old machine pressed juice. Almost no one chose the fresh hand squeezed juice.

Don't be afraid to juice ahead of time, but always use freshly-squeezed juice.