First you need to get that cup of whey. If you happen to have some fresh whey in your fridge thats great. If not get some whole milk organic live cultured yogurt or better yet make some. Next you need to drain the whey from that yogurt, so you will need some very clean cheese cloth, a bowl and a few rubber bands. The easiest way for me to do this is to drape the cheese cloth into the bowl and add the yogurt onto the cheesecloth. Pull the sides up and gather them at the top and hold the whole thing closed with a rubber band? Straining yogurt into cheesecloth Now loop another two rubber bands through the ones holding your pouch closed and use this new ?loop? to hang the pouch above the bowl from a knob on your upper kitchen cabinet? Hanging my yogurt to drain Once the yogurt drains for a few minutes grab a measuring cup and see if you have a full cup of whey. Once you do go ahead and pour the whey into the glass jar. 1 cup of whey Next get your favorite lemon squeezer or your citrus juicer and start juicing 12 lemons. Organic lemons Amount of juice will vary, this is how much I got out of these 12 lemons Add your fresh lemon juice to the whey in the gallon jar. Give it a quick stir. Now you will need to decide how much sugar you want to use. You need to use at least a 1/2 cup of sugar (the probiotic need to eat) up to a full cup. I used 3/4 of a cup in mine. I like the level of sweetness left after the fermentation. Not too sweet not too tart. Next fill the jar with a gallon of cool filtered water and mix very well to distribute the whey and dissolve the sugar. Now we wait Now keep the jar on your kitchen counter (room temperature) and wait for 2 days. The fermentation will eat some of the sugar you added so it will be less sweet than when you started. Enjoy, Its very tasty, full of probiotics and vitamins. Your family will love it!