Here's a tip for brethren in Christ who are serious in Bible study for themselves, as it relates directly to this matter of the 'new wine' and 'old bottles' parable that Lord Jesus gave.
One of the remarks Lord Jesus would often use after giving a parable is something like, "Who hath ears to hear, let him hear." (Matt.13:9). In Matthew 13:10-17, Jesus answered His disciples' question of why He spoke to the multitudes in parable. The really important reason He said was that because it was given to His disciples to know the mysteries of the kingdom of heaven, but to the multitudes, it was NOT given.
This points to Jesus teaching us that there is actually another level of understanding He put in His Word for those who have been given 'eyes to see, and ears to hear.' And I'm not creating some mysterious secret with this, for being able to 'see with eyes to see, and ears to hear' is not that difficult to receive from Lord Jesus. We simply have to do Bible study His Way, and not the world's way. We have to ask Him to open His Word up to our understanding so that we may 'see' (spiritually) and thus understand. And we have to do what Apostle Paul recommended to Timothy, to study to show oneself approved of God, a workman who need not be ashamed, rightly dividing the Word of God, (which means line upon line, chapter by chapter, book by book, all of it.)
Jesus' method of parable is actually a common language tool used in all... languages. All languages have expressions, idioms, analogies, allegories, parables, sayings, etc. Lot of them do not translate perfectly between languages. And example... "I'm so hungry I could eat a horse." Someone saying that is giving an expression, an analogy. They do not mean they would eat a horse. They are only using the size of a horse to display the level of hunger they have. You could use an elephant and it would still get the point across. It draws a 'picture' in your mind for you, and that's the key.
What's the old saying, 'a picture is worth a thousand words?' That is what Lord Jesus' parables are designed to do. This is why God's Word uses so many natural things, like agriculture, etc., in His parables. It's something that the majority of the people were familiar with. Yet they contain the 'gist' of a Biblical concept, that once you understand the metaphor, you've got the Message, and the Message then acts as an Anchor within God's Truth in His Word. It can serve as a GUIDE within His Word.
Here's another example Jesus gave...
Mark 8:15-21
15 And He charged them, saying, "Take heed, beware of the leaven of the Pharisees, and of the leaven of Herod."
16 And they reasoned among themselves, saying, "It is because we have no bread."
17 And when Jesus knew it, He saith unto them, "Why reason ye, because ye have no bread? perceive ye not yet, neither understand? have ye your heart yet hardened?
18 Having eyes, see ye not? and having ears, hear ye not? and do ye not remember?
19 When I brake the five loaves among five thousand, how many baskets full of fragments took ye up?" They say unto him, "Twelve."
20 "And when the seven among four thousand, how many baskets full of fragments took ye up?" And they said, "Seven."
21 And He said unto them, "How is it that ye do not understand?"
KJV
When Lord Jesus fed the five thousand, and the four thousand, He sent 'whole loaves' of the Bread out with the fishes. Recall what God's Word uses a loaf of Bread as a symbol for (i.e., Christ as The Word, untainted, like the "new wine" idea. John 6:35).
Thus the loaves whole, went out to the multitudes. But what returned with the fishes? Baskets of "fragments", a lot more food than what originally went out to the multitudes, and it was no longer whole, but in pieces.
At the start, Lord Jesus warned about the "leaven" of the Pharisees of king Herod. What does leaven do in baking bread? It makes the bread rise, and thus appear like you've got more bread. Unleavened bread does not rise, and is like pita bread, and very good fresh I must admit since I have been to the middle east in Iran in my military days.
Thus the concept of 'fragments', 'leaven', is about IDEAS ADDED to the whole LOAF of BREAD (God's Word). That's what the baskets of fragments Jesus' disciples gathered back up represents. It reveals the getting away from the pure Load of Bread that God's Word is, and instead cutting it up into pieces. And usually that cutting up means adding to it so you don't get the pure LOAF anymore. That may seem like too much information about what Jesus showed, but it is not. He drew a 'picture' that is worth a thousand words. And He expected His disciples to understand, since they were supposed to have ears to hear and had not hardened their hearts to His Word.