Ricotta - cheese making 101

I found an intriguing recipe for a pistachio-marzipan ricotta filled cake in the latest issue of Saveur - I so want to try and make it- looks so yummy, that with the fact I've never tried pistachio marzipan.  I've only had the traditional marzipan made with almonds.  So somewhere in reading this recipe I decided I wanted to try and make everything from scratch.  So the first step is to make the ricotta.  Yesterday I twiddled away several hours for shopping, one failed attempt, and one success for ricotta cheese.
It's actually pretty easy; the hard part was finding the citric acid.  You can find it online but then you have to pay the shipping which ends up being more than the product itself.  I checked in numerous grocery stores and vitamin shops but no luck.  I briefly wished I was back at my old job with easy access to all sorts of molecular grade chemicals (probably not the best idea)!  Finally I found everything I needed - cheesecloth, local whole milk, and citric acid - at Strawberry Fields, which is a local gourmet grocery.  It was mixed in with the spiced and baking supplies - Whole Foods may carry it too, but not sure.
At home, I broke out the Garde Manger cookbook from culinary school and found the cheese recipes.  It's been a long time since school so I had to consult my notes which weren't so helpful.   Here's how I did it:

 

Equipment:

• Thermometer (meat one will do- need to register 185F)
  
• Whole Milk- 1 gallon (good quality milk)
• 1 tsp. Citric Acid
• 2 tsp. kosher salt
• 2 oz. water
• Cheesecloth
• Strainer/Colander
• Large pot
   

Steps:

• Dissolve the citric acid in the water (NOTE:  make sure it is fully dissolved- I think I missed this step my first try)
• Heat the milk, citric acid (in water), and salt over medium heat in a large stock pot.  Keep the thermometer in the pot to monitor the temperature.   Stir the milk often to prevent scorching - heat until the temperature reaches 185F (85C). 
• When it's reached 185F, remove from heat and allow it to rest for 10-20 minutes - this will allow for curdling.
• Line a colander with the cheesecloth and place over a large bowl.  Drain the curd into the cheesecloth-lined colander, and place the whole contraption in the refrigerator for at least 1 hour - up to 4hours. Voila- your cheese is ready.  You can store it in an air tight container for up to 1 week in the refrigerator.

Problems- well- these happen, especially during your first attempts.  My first run resulted in about 2 curds!  So without straining, I placed the milk back on the heat, dissolved another tsp. of citric acid (making sure it was completely dissolved), added a pinch more salt, and watched the temperature carefully.   When it reached 185F, I had a lot of curd.  It's all about trial and error.  Good luck!

Note- the little brown spot is from scorched milk!  Oops