Joy Division,
Most people aim for a 5.5 gallon post boil because after siphoning from the primary fermenter, some liquid is left over and that likely accounts for around a half gallon, leaving you will 5 gallons to bottle / keg.
To determine water volumes and temperature, I recommend using
www.brewheads.com http://www.brewheads.com/batch.php
It works great. I have always assumed 3 degrees loss temperature for my 10 gallon igloo container mashtun. That assumes I have not prewarmed my igloo with hot water. If you do prewarm your mashtun, you can remove mashtun equipment temp loss anywhere from 0-1 degree.
When you add your initial volume, it will be based on your water to grain ratio or how thick you want the mash to be at. It is common to use the recommend 1.25 quarts per pound of grain. For your recipe, that would be 3.44 gallons of water.
The temp you want the 3.44 gallons at will be dependent on the initial temp of the grains. I assumed grains at 70F and mashtun loss of 3F, that gave me an initial strike temp 164.7F for the 3.44 gallons.
Another big tip for all grain brewing is to calibrate your brew pot using a wooden dowl or stick. After I collect my initial runnings, I know exactly how much more water to add to get to my target pre-boil volume. Because the grains have already absorbed water with the initial mash, any additional water added will come out.
Your fermentation temps for an ale below or near 70 is best. Most people do not have temp controlled units for fermenting. It will improve the quality and consistency of your brews, but it would not be mandatory for this brew IMHO.
Hope this helps!
Kevin
