Tail and watch, filter and extract string

Question

Lets says I have a file called test.log more rows being added all the time:

one|two|apple|four|foo1
one|two|pear|four|foo2
one|two|apple|four|foo3
one|two|peach|four|foo4

I want to tail it but am only interested in lines that say apple, and I only want to see the string after the last pipe.

To filter by apple I can use:

tail -f test.log | grep apple

This outputs:

one|two|apple|four|foo1
one|two|apple|four|foo3

Now to get the string after the last pipe I thought I could use:

tail -f test.log | grep apple | awk -F '|' '{print $(NF)}'

But this outputs nothing.

If I remove the -f option from tail it works but then I can't watch my log file.

The problem is awk hangs as described in this answer. I could not make the solution outlined there work for me.

So maybe using cut would be easier than awk. There are a set number of pipes so I could just do:

cat test.log | grep apple | cut -d\| -f 5

Outputs:

foo1
foo3

But when I watch with:

tail -f test.log | grep apple | cut -d\| -f5

Again I get no output.

Is there an one liner I can use to tail this file, filter it, and extract the last bit?