I'll start by saying this is easy. Not 'I cook professionally and consider this to be a basic procedure,' but actually, totally, easy. And delicious. Tomato water has a million uses -chilled 'consommé,' stock to cook risotto, I even like to use it in cocktails. All it requires are tomatoes, blender, strainer, salt, and about 24 hours.
And this time of year, tomatoes are both exceptional and plentiful.
To get started, organize your equipment. If you have your blender, strainer, etc at the ready, you can knock this prep out in minutes. Once that's ready, grab your tomatoes. This is great for using up tomatoes that are, well, past their prime. You can't use rotten tomatoes, but slightly bruised or really soft ones are fine for tomato water so you might as well use them up here. I use roughly 1 tbsp of salt for every pound of tomatoes -you can make as much or as little as you like.
If you need it, here's a quick link for the simple recipe.
They need a rough buzz in the blender, so I cut them into quarters to speed up the process. Add the salt now too. You do not need to totally liquify your tomatoes -small, rough chunks are fine. The salt pulls out the moisture, the blending helps speed the process up. It's easy to go overboard with the salt, so keep that in mind. You can change the tomato water from sweet to salty with a really big pinch of NaCl.
Once blended, pour into a very fine strainer -I use a chinois with a coffee filter, but a few layers of cheesecloth work well too. Set it in a container to drain and place in the fridge overnight. Twenty four hours later you will find the contents of the strainer pretty dried up (see the pics below) and a clear, golden, intensely flavored water in the container. Tomato water does not have a long shelf life. You'll need to keep it in the fridge and use it within a few days, but the applications are endless. Let's hear about your favorite uses in the comments.