Black currant marmalade only water and sugar

Ingredients are measured by glasses for ease of measurement. Kitchen scales were bought by me quite recently and my torment when weighing products without scales simply knew no bounds.
So this recipe for making currant marmalade is suitable for those who do not have kitchen scales. Everything is simple and get ready quickly.
Black currant berries should be sorted, washed and dried using a clean dry towel.
Then fill the currant with water, and when the mixture boils, add three cups of granulated sugar.
With the next two boils, we also add three cups of granulated sugar each time.
When foam forms on the surface, it must be removed.
Cook marmalade for 2-3 minutes.
In hot form, black currant marmalade must be spread out in clean, dry jars and closed with lids.
It is recommended to store at room temperature away from sunlight.
If you boil the mixture, then you won't get marmalade – it just won't harden, so when cooking, strictly stand for 3 minutes.
So that the marmalade does not freeze in the pan during its laying in jars, make the fire under the pan minimal and show maximum skill.
And you should not use the ingredients in other proportions.