Wash your fruits well, cut off the ends and discard those parts. Cut your fruits into quarters, if they are bigger then mine, then just cut them a little smaller. Place into a cooking pot with a part of the water, that means add about 300 milliliter or 1 ½ cups to the fruit. Cook the fruits until soft for about 15-20 minutes.
Once cooked, mash directly with a stick blender. If you are using a regular blender, let cool a bit first and transfer the fruits to the blender. Blend to a smooth paste. Then grab a mixing bowl with a sieve and strain the pulp so that the guava seeds are separated from the pulp. Discard the seeds.
Add the pulp back into the cooking pot and add in all the sugar! Place on the heat, keep it on medium and at the end pour in the remaining water, which is about 100 milliliter or ½ cup.
From now on just stir the content and always keep the heat in mind. The mass should never burn but it should also reduce enough in a timely manner. I would keep it on induction on a medium heat level. As long as you stir nothing can go wrong anyway!
You will need to stir the content until it thickens in such a way that you can add a little of the candy mass into water and if it doesn't dissolve but stays firm, then it's ready. In total you will be stirring and reducing the mass for about 60-80 minutes non stop.
Grease your mold.
If you have poured the mass into the mold and if after having cooled down, you tried to cut but realized it was way too soft, then just take back the whole mass into something like a non stick pan and just stir fry it for another 10-20 minutes or until the whole thing gets thicker (do the water test). Then you can just pour it back into the greased and prepared mold and cut it when it has cooled down.
Even after letting the guava paste cool for 1-2 hours, you can already cut the Guava cheese in its still warm state into whatever you like. The Guava cheese can be cut into diamonds as I did, by cross-cutting.
Use only organic/untreated Guavas for this because the fruits are not peeled!
Guava pulp is slow cooked over a long period of time until the paste thickens. After that, it is left to cool in a buttered mold.
It's easier to work with a nonstick pot! So what I like to do is I first cook the mass in a higher steel pot then after 60+ minutes cooking I transfer it into a smaller nonstick shallow pan. The nonstick will help you to get the correct consistency quickly which is due to the shape of the pan too. Also, at some point, you are just fed up looking at the same pot :D
I also use brown sugar because the flavors suit the guavas better, however, you can use regular sugar too but if you can try to use only brown sugar.