We recently talked about the processes of mashing and sparging while home brewing beer and what they involved. We only lightly touched on the process of sparging, which is also called “lautering.” There are actually a couple different types of sparging.
Batch sparging is the most simple form of sparging. After mashing you completely drain the liquid from the mash tun. More water is added to the mash tun, stirred, and then left to sit for at least half an hour before it too is drained. The two drained batches are typically combined to create the wort.
While batch sparging has historically been seen as less efficient than other methods, modern grains prepared specifically for brewing beer have allowed the efficiency of this process to become equal to other sparging methods. Batch sparging is desirable because it is a much faster process than other sparging methods.
Batch Sparging: Parti-Gyle Brewing
It is possible to create multiple different beers with the batches emptied from the batch sparging process because each successive batch will have a lower specific gravity than the previous and will create a lower-alcohol beer. Brewing in this fashion is called “Parti-Gyle Brewing.”
Usually in Parti-Gyle brewing the first batch that is sparged, called the “first runnings,” is used to create a strong beer, maybe a stout or IPA or a strong Scottish ale. The second runnings are used to create a middle-of-the-road beer, such as a lower-strength Scottish ale. Any further runnings would be used to create a very light, low-alcohol “session” beer.
Fly sparging, also called “continuous sparging,” is a process that was created to maximize the efficiency of the brewing process by getting as much of the sugar out of the mash as possible. A “sparging arm” is used to slowly sprinkle water into the mash tun and the liquid in the mash tun is allowed to drain out at the same flow rate as the liquid is entering the container.
Equalizing the input and output flow rates allows the liquid containing the sugars from the mash to be drained from the mash tun equally, rather than allowing a “channel” to develop which allows water to flow out of the container while bypassing most of the grains and sugars. Channeling reduces the efficiency of the process.
Fly sparging is much more hands-on than batch sparging because it requires the brewer to monitor the input and output flow rates to keep them balanced, as well as monitoring the specific gravity of the water mixture in the mash tun. Usually when the specific gravity has dropped between 1.008 and 1.010 the sparging is stopped to prevent tannins and other undesirable material from entering the wort.
Have you tried either type of sparging? Which do you prefer and why?