The "Brew Bag" is a simple and very useful mash bag for home brewers who want to start with mash brews according to the popular "Brew in a Bag" method. This allows you to perform whole grain brewing while keeping your equipment costs minimal and your brewery as simple as possible! I am personally a big fan of this method and use it about half the time when brewing. It's a perfect way for beginning and experienced homebrewers alike to KISS (keep it simple, stupid)!
I recommend insulating your kettle and turning off the heater during mashing. A properly insulated kettle will hold its temp within 1-2C over the mash period. If you do want to add heat during the mash, just raise the bag above the heat source, and stir the wort while heating.
Note: These 200 micron bags do not perform well with pumping the wort - I have tested this extensively and do not recommend it! Choose the 400 micron brew bag for pumped systems.