Basically you can make most fruits into a cordial, simply by making up what is effectively runny jam, with the sugar acting as the preservative. These are robbs in older herbals. Syrups really.
However, if you can find the equipment, and buy decent bottles, then it's quite possible to bottle the fruit rich liquid without quite so much sugar, by pressure cooking to sterilise and stop fermentation.
It's very logical, but needs care to do it properly.
British Red recommended the Ball's Blue Book on preservation by canning and bottling. He was quite right; it's a goodie

and well worth acquiring.
There is another way, but it needs you to have ample freezer space. Simply make up fruit syrup and freeze it. It becomes like sorbet, but it dissolves into a lovely drink too
I usually make elderflower, blackcurrant, strawberry, raspberry and rhubarb syrup, every year. I'm not terribly innovative

I know there's a massive plethora of fruits that would make really good cordials. I occasionally make plum, not apples though, lovely though they might be. They thicken up with the pectin. Peach and grape are lovely, melon's awfully sweet somehow, haven't tried mango, though I admit I fancy that one
A few years ago I posted a thread on the wild strawberry syrup that I make. This is from it.
The little hautbois strawberries are fruiting merrily; they taste almost sweetie strawberry like

nothing like the overblown almost tasteless supermarket fruits. They make a most wonderfully tasty syrup that is excellent in home made chocolates as well as for deserts. I like a little in tea in the late Autumn when the first cold, damp chills come in.
I know of them as this name from childhood, but I think of these as our wild strawberry since they grow so profusely along burnsides, etc., I don't think they're pure hautbois, I think they must surely be a mix, but the scent and taste is wonderful
They always have a little present for those who look

from early spring right through to late autumn. They're setting out runners now, I will happily bag and post a few.
Wild Strawberry Syrup Recipe.
I pick the ripe ones, even the 'raisined' dryish looking ones, and then just and no more, cover them in water.
Bring to the boil, cover and turn off the heat. Leave until they're cool. Overnight's fine. Stain through a sieve lined with muslin or paper kitchen towels (works really well), measure the liquid and add the equivalent of sugar. If I get 500ml of liquid, I add 500g of sugar.
I'm not making jam or jelly, I'm making syrup. That means that I don't want to boil for ages, I don't want the cooked fruit taste, I want the sweet strawberry flavour in something that preserves it tastily.
Bring slowly to the boil, stirring until all the sugar crystals are dissolved.
There will be a little froth, gently skim it off into a small bowl. Don't throw it away, it might not be quite as pretty as the syrup but it's great over ice cream or to dip bread into

I let the liquid reduce a little, and then remove the pot from the heat.
Meanwhile prepare bottles by washing and rinsing in boiling water. This year I'm using the wired ones, but tbh, usually I just use washed out condiment bottles and they work fine. Just make sure the lids aren't tainted and are sound enough to seal well.
I pour the hot, but not boiling, liquid into very warm bottles and seal pretty much straight away. I really don't want anything in there to cause any fermentation, but there should be enough sugar in the mix to keep everything sound anyway.
If you pour too hot liquid into too hot jars or bottles the syrup will boil, and that's messy and not advised. It's a 'think about what you're doing' kind of activity this
M