I am a newbie myself but from what I read most people take the fresh fruit and process them right away. I'de remove the stems but the cores are optional, most just process those too.
My first mini batch i processed today had no stems or cores and i used a juicer then strained the juice that...
So I was searching on ways to extract pear juice without using a press, one of such ways was to use a food processor to blend up the pears then put them in a cheesecloth to strain out the pulp/skin..etc...
Lets just say all I am left with is Pear juice/pulp.
Was this a stupid newbie...