Soak the guavas in a bowl of water with 1 tbsp of baking soda or vinegar (not both) for 5-10 minutes.
1 tbsp baking soda or vinegar
Thoroughly rinse the guava, scrubbing the surface to remove any dirt or pesticides.
Set aside 4 to 5 guavas, and cut the rest into quarters.*If you do not want any chunks of flesh in your paleta, you can skip this step and the next 4 steps (steps 3-7), and just quarter all of the guavas.
1 1/2 lbs guava
Cut the 4-5 guavas you set aside in half.
1 1/2 lbs guava
Scoop out the seeds in the center
Combine the scooped out seeds with the rest of the quartered guavas.
Cut the scooped out guava skins into small pieces
Add most of the sugar into the bowl with the quartered guavas and seeds. Reserve about 2-3 tbsp of sugar to add to the chopped up pieces of skin, if using.
2/3 cup sugar
Mix together, cover and let it sit for about 30 minutes to macerate. After 30 minutes, use a masher or your hands to squeeze the mixture, breaking it down as much as you can. Leave the bowl of macerated guava skins as is and just set that aside for now.
Add water to loosen the mixture so it's easier to strain.
1 1/4 cups water or guava nectar
Push the mixture through a sieve until there are only seeds and some skin remaining, then throw those away.* If you prefer to keep the seeds in your paleta, you can skip this step. The seeds are very nutritious, but I personally do not enjoy eating them.
Add the salt, juice of 1 lime, and cellulose gum if using. Then blend the mixture thoroughly, so the cellulose gum dissolves properly. I used an immersion blender, but you can also use a traditional blender. *cellulose gum is a stabilizer and it is totally optional. It prevents large ice crystals from forming, which makes the texture much smoother with a better mouth-feel.
1 lime , 1/4 tsp salt, 1/4 tsp cellulose gum
Optional: for aesthetic purposes only, you can add whatever type of red food coloring you prefer. You can use beet juice or food coloring. I used Watkins Food Coloring because it doesn't contain any artificial dyes.
Fold in the reserved macerated guava skins (if using).
The mixture will be thick, but still pourable. Pour into a clean popsicle mold, leaving a little bit of space at the top to expand, then put in the popsicle sticks and freeze for 8 hours.
To remove the paletas from the popsicle mold, you can place the entire mold into a warm water bath for 20-30 seconds, or use a popsicle stick to slide down the sides of each paleta to loosen them from the mold.If you're a popsicle biter like me, I recommend letting the paletas sit at room temp for just a couple minutes to soften before biting into it!
Notes
How to store the paletas
I do not recommend leaving the paletas inside the popsicle mold, unless you plan to finish them all within a few days. The longer they stay in the mold, the harder they will be to remove. Instead, I recommend taking them all out and storing in an airtight tupperware or individual plastic baggies (which come with the popsicle mold I recommend). If you need to prolong the shelf life of the paletas, use a vacuum sealer on the plastic baggies.
How long will they last?
Since they are frozen, they can technically last up to 3 months of even more if stored properly. However, the longer they are in the freezer, the more ice crystals will form, making it hard and icy instead of smooth and somewhat soft. I think it is best to eat all of them within a couple of weeks.