Brew in a bag is one of the simplest all-grain or partial mash methods out there. It only requires a single brewing vessel to get good results. Efficiencies in the mid-70's is not unheard of without so much as a single washing sparge and you can scale this process up or down without much more than changing out your kettle.

To perform the simplest for of brew in a bag you only need:

A brew kettle sized appropriately for the batch, and a grain bag large enough to hold the grain for the batch. I usually get a very large grain bag, at least as large as my brewing pot.

Below I will describe the simplest of all techniques

1. Fill you brew kettle with your strike water volume. You should make sure the kettle is not undersized, as you will be adding your grains in here and we dont want to overflow.

2. Make any water chemistry adjustments called for in your recipe. (this is not a necesarry step, but if you are going to make adjustments, now's the time.)

3. Heat the water to the proper strike temperature based on the volume of water and the amount of grain in the recipe. Your recipe should tell you the proper temperature, if not use a strike water calculator to determine it. (http://www.brew365.com/mash_sparge_water_calculator.php)

4. Fit your grain bag over the mouth of your kettle and begin filling it with your crushed grain slowly. Stir the grains as they go in to ensure even wetting without balling. -- If your grain bag isn't large enough to fit over the kettle, don't worry. Just fill it with your grains and dip it in to the water full. Give it a few seconds to soak then try to stir it a bit.

5. Now it's time to wait and let the enzymes do thier thing. Tie or clamp the bag to a spoon or the handle of an upside down kettle lid so you can easily extract it after the conversion rest. And wait.

6. After the alloted time, or when conversion is complete as indicated by a starch conversion test (http://homebrewforums.net/index.php?p=/discussion/25/how-to-tell-when-your-mash-is-complete) raise the bag up slowly, and let it drain. You can use the water you need to add to reach to full boil volume to help wash the remaining sugars off the grain, this is called sparging.

7. Raise the wort to boiling and complete the recipe as described in the instructions, making the necesary hop and adjunct additions as you go.

Congratulations on your first all-grain or partial mash brew session!

Happy Brewing!