I've been a Barista in high end coffee for about 4 years now. One of the things you learn early on is that it is distasteful to ever ice espresso. Many go forward never questioning why this is such a bad idea, but I have an inquisitive mind and looked into it further.
It turns out that coffee is high in chlorogenic acid, which, as the coffee cools, forms quinic acid, which has a noteable and overwhelming astringent flavor. So the task is to brew coffee in a way that does not involve heat, and also reduces the apparent acidity. In the 60's the Toddy method became popular and it produces a finished product that is notably less bitter and actually puts forward a deep caramel and chocolaty flavor. It is perfect for a warm day.
I decided to make my own cold brew coffee brewer.
Step 1: Materials
-6oz of a well roasted coffee
-one piece of felt (.29 cents at michaels)
-two large coffee filters
-a two-liter bottle
Step 2: Begin
Cut the bottom off of the two-liter bottle.
Step 3: Stand
Use a broad glass to act as a stand for the brewer
Step 4: Filter
Fold a piece of felt
Step 5: Filter insertion
Roll up the felt and stuff it into the opening of the brewer.
Step 6: Weigh
Weigh out 6 ounces of a good, quality coffee. Bad coffee will only get you bad cold brew.
Step 7: Grind
Grind to the coarsest possible setting.
Step 8: Make coffee "tea bags"
Split the coffee into two large coffee filters.
Step 9: Tie
Tie them off with thread.
Step 10: Set in your brewer
Set them in your brewer, fill with a little over 6 cups of good, clean water
Step 11: Brew!
Brew for 12-24 hours, this batch brewed for 14 hours.
Step 12: Take off the cap!
Take off the cap and a slow drip should start.
Step 13: ALMOST THERE!
So so close
Step 14: Enjoy!
End product. A super clean, crisp, cold brewed coffee. You can use this as a concentrate and dilute with a few ounces of water or drink it straight up. Tastes delicious and huuuuuuuuge caffeine content.
The double filtration is extremely important. A lot of places that do cold brew use the reusable fabric filters, but they tend to leave solids in the coffee and it gives it a certain grittiness that I can't stand. Double filtered cold brew coffee is one of my favorite coffee preparation methods.