Mix the heavy cream and half and half in a 2 quart saucepan.
Heat to 85 degrees and add the whey or other starter culture. Use a wire whisk or spoon to mix it well. Put a lid on it and set it in a warm corner (70-80 degrees) to clabber. I made mine on a hot day and it was ready after 8 hours, but for the best health benefits, you'll want to ferment it for a full 24 hours.
When you're ready to make the Panna Cotta, add the cold milk to a 1 cup stainless steel measuring cup or a small stainless steel bowl.
Sprinkle the gelatin into the milk to bloom.
While waiting for the gelatin, slowly heat the cream to body temperature, about 90℉ while stirring to avoid hot pockets. Then add the honey, vanilla, lemon zest, and almond extracts to the clabbered cream and whisk it in.
After about 5 minutes when the gelatin has bloomed, place the cup or bowl on the stove and heat till the gelatin is dissolved. Don't overheat it or the gelatin will not gel properly. It needs to be just a little warmer than body temperature.
Once the gelatin is dissolved, whisk it into the warm clabbered cream. Stir well to make sure it's evenly incorporated.
Prepare your molds by either rinsing in cold water, or greasing them lightly. If you'll be serving it in single serve dishes to eat with a spoon, you don't need to rinse or grease them.
Pour the clabbered cream mix into the forms. Cover and place into the refrigerator to chill and set for 4 hours or longer.
To unmold, dip the bottom of the forms in hot (not boiling) water for about 15. This will help release the filling. Run a thin knive around the top edge. Invert onto a serving plate and add your favorite topping. You can also pour sauce onto a plate and invert the Panna Cotta into onto a plate rinsed with cold water or bench knife, then carefully slide it on top of the sauce and avoid splashing. This can be a bit challenging, so it's best to have a few extras on hand in case one or two mess up. They are just as delicious when they are messed up though!
Decorate with some berries or white or dark chocolate curls, edible flowers, lemon balm leaves, etc. and serve immediately. Enjoy!