If your an all-grain brewer, you may want to read this. I always wondered how to determine the efficiency of my mash. While this article won’t help to calculate your efficiency, it will give you some basic steps to help make your process more efficient.
Milling your Grains
How well your grain is crushed will affect your mash and sparge. You can have your grain crushed at the brewing supply store or you can purchase your own grain mill for more control as you may want to make adjustments for different grain sizes. For example, wheat has a smaller kernel size than barley. You should aim for a well crushed grist with a mix of large and small particles and unshredded husks. The husks are an important part of the mashing process. The husks allow water to flow through the grain bed, extracting the sugar and preventing a stuck mash.
Mash out and Sparging
Raising the mash temperature to 168o F (mash out) and then rinsing the grain (sparging) with hot water (168o F) helps to flush out as much sugar from the sticky mash as possible. Sparge water temperature should not be above 170o F as husk tannins become more soluable above that. At the same time, the temperature should not be much lower either as the flow won’t be as good.
Start to drain the mash from the mash tun at just a trickle. Start adding the sparge water slowly to the exposed grain bed. It should take 30 minutes or more to drain 6 gallons of wort from your mash tun. Continuous sparging will usually result in the highest yield. Continuous sparging is the process of adding small amounts of sparge water to the mash tun slowly. Homebrewers typically will add a fairly large amount of water periodically, which is a little less efficient.
Deadspace is the amount of liquid in your mash tun that is under the false bottom. The problem here is that this liquid is good wort and you want this extracted to your boil kettle. This can be accomplished with a dip tub under the false bottom, whish can help you drain the mash tun almost completely. However, the larger the deadspace, the more wort that is left behind. Also, the amount of deadspace will affect your mash thickness calculations, which is a completely separate topic.
Choose the Right Mash Tun
Your mash tun and false bottom can greatly affect your mash efficiency. A tall brew kettle shaped mash tun reduces the deadspace. The false bottom should cover the entire bottom of the vessel and have minimal deadspace under it. This will provide an even flow across the entire grain bed giving you getter efficiency.