This list assumes that you already have all the things to brew an extract batch of beer

• Big Stock Pot - AT LEAST 12 qt, I use a 20 qt pot. You can probably use the same one you make extract beers with if it's big enough.
• Bag - This is the magic of the method. You need a fine mesh bag that fits the inside of your pot. I bought a sheer curtain from Walmart and got my grandmother to sew it into a bag. Essentially, you want a bag that the pot will just fit in.
• Colander - This isn't necessary, but I find it helpful. I have a stainless colander that I have rigged to fit over the top of the pot so that I can let the grain bag continue to drain (lauter) while the boil begins. I tied some wood scraps to the handles. It's embarrassing, but it works. Some day I'll come up with something more elegant.

Carefully measure one gallon of water into your boil pot and boil it for 30 minutes. After 30 minutes, quickly cool the water by placing your boil pot in a sink full of cold water. After it cools, measure how much water is left. Subtract this amount from one gallon, and multiply it by two to figure out your boil off rate in gallons per hour. If you use a different pot, or a different heat source, you will probably need to re-calculate your boil off rate. I've calculated .6 gallons per hour for my pot and stove.

Calculate Water Needed

You will lose water in two ways. The grain will absorb some, and the rest will evaporate during the boil. We've already calculated the boil off rate, so we need to calculate the grain absorption loss. Assume 0.12 gallons per pound of grain in your recipe. After a couple of batches, you may find a more appropriate number, but this should get you started.

In my particular recipe, I'm using 2.41 pounds of grain. If you multiply 0.12*2.41, you'll find that the grain should absorb 0.29 gallons.

If you're doing a 60 minute boil, just add the grain absorption (0.29) to the boil off rate that you had calculated before (.6). This should give you your total water loss of .89 gallons.

If you're doing a 90 minute boil, you'll have to adjust your boil off by multiplying it by 1.5. For a ninety minute boil of this recipe, I get a total water loss of 1.19.

Add your total water loss to the desired size of your batch and you'll find the amount of water you'll need to start with.

Starting Your Brew

Preheat your oven to 150F or as low as it will go.

Fill your brew pot with the total water needed and heat it to your desired mash temperature.

Put the bag in your pot and stir in the grains, making sure to get out all the clumps.

Check the temperature, it probably dropped below the desired mash temperature. Keep the heat on while stirring until you get back to the desired mash temperature.

Cover your pot, and put it in the oven and start a timer for one hour. If your oven's temperature is above your desired mash temperature, you can just turn off your oven. You're not using the oven to heat the mash; it's just to keep it from losing too much heat.

After 60 minutes, remove the pot, take off the cover, and put it back on the burner while stirring to get to 170F for 10 minutes if you want a mash out step, which is optional.

Now pull the bag out of the pot and let it drain back in. This is called lautering. To save time, I put a colander over the top of the pot and put the bag in the colander to continue to drain while I start the boil.

When the boil starts, you can remove the colander; the bag should be pretty well drained by now.

The rest of the brew progresses just like an extract batch. Add the hops at the times required by your recipe.

When the boil is finished, chill the wort by putting your pot in an ice bath in the sink. One gallon should cool pretty quickly. When it gets to the proper pitching temperature, siphon, or pour the wort into the fermenter.

The one gallon carboys hold a little more than a gallon. I recommend using the foam control drops in the fermenter to reduce any losses to blow off.