Want to place an ad email firstname.lastname@example.org
$50+GST / month
When this is complete, I start running off into the kettle at a slow rate - approximately .5 Liters per minute - here's a photo of what this looks like...
I maintain this flow rate for the rest of the process, untill the kettle is full. Obviously - there is not enough liquid in the mash tun to fill my kettle, so I pump hot water into the top of the mash at the same flow rate as the wort going into the kettle. This is "fly sparging". Once you have the input / output the same (takes 5 mins to acheive), you basically leave it until you have collected as much wort as you need in the kettle for your boil. It pays to have about 5 cm of liquid above the grains to aid in the sparge...
You can see above that the level in the mash tun is down considerably complared to how it was post recirculation. I took a coiple of photos of the position of my valves - but in the end it doesn't matter to you how they look: I have different valves to you - so it cant be compared. The principle is what counts - and here is my take on it - and why fly sparging is my preferential form of sparging. Sweet wort has a much higher density than hot water. What happens during the sparge blatantly flouts this scientific theory. Many readings say that sparging "rinses" the grain - but I would go one step further, in that fly sparging "displaces" the sweet wort before it rinses the grain. The hot water sits on top of the sweet wort in the mash. Gravity pulls the sweet wort out of your mash tun, and the hot water rinses the sugars away from the grains on its way down. I have attached a photo of some of my sweet roggen wort pre boil - it is not the 1st runnings. Imagine that the liquid interplay is the same while it is sitting amongst the grains.
As you can see - the hot water is sitting on top of the wort. The principle is the same in the mash tun - provided you don't splash, or agitate the liquid in there. As you add more hot water, the wort drains out the bottom - eventually the water finds its way to the outlet... hopefully the kettle is full by then! So the brew is fermenting away now - I pitched at 12 degrees, and its fermenting happily at 17 degrees. I had to attach a blowoff tube again - and I lost about a litre of beer during the active fermentation phase. Cheers!