Empty the 1 gallon of whole milk into a large pot and place on medium-low heat. Stirring ocassionally, heat to a low, rolling boil.
Place a colander over a large bowl, and line the colander with clean cheesecloth. Shake the cheesecloth to be sure all lint, hair, and other fibers are dislodged and it's clear of debris.
Once steadily boiling, add 1/4 cup of lemon juice and stir it into your milk pot. Watch for coagulation, where small clumps that look like cottage cheese curds begin to stick together and a yellowish, watery fuild appears in your pot (the whey). If the curds aren't forming well or the pot still looks very milky, add the next 1/2 cup of lemon juice and stir.
Once the pot has separated well into curds and whey, turn off heat, and pour the contents carefully into the cheesecloth-lined colander. The cloth will catch the curds and allow the whey to pass through.
Stop to rinse your cheese pot before it sets up.
Dump the curds into a container with a lid and use a fork to lightly break them apart into size, per your tastes. If you're going to add 2 teaspoons of sea salt, do it now.
Pour 1/2 cup of cream on top of the curds and fold the curds into it. Allow it to sit for 5 minutes.
After 5 minutes, examine your cottage cheese. Is it creamy enough? If not, add the other 1/2 cup of cream and fold the curds into it. Allow this mixutre to set up in the fridge for at least an hour. You may also eat it right away while it's warm.
After refrigeration, you can check the cottage cheese for consistency. The cool temperature will set the cottage cheese curds and you may discover you want more cream.
Store for about a week in the fridge, if you don't gobble it up before then.