Fly sparging...what should be left in the mash tun?

I’ve been reading a lot about fly sparging and understand the process of adding sparge water at the same rate as the runoff and keeping ~1in. above the grain bed, etc. etc. Where I am getting confused is how much sparge water do I need and what should be left in my mash tun?

Do I keep continually add sparge water and collect the runoff until i reach my target boil amount and then stop draining/adding? If so, wouldn’t I have a mash tun full of sparge water + grain once I’ve reached my boil amount?

Or, do I only add enough enough sparge water so that I reach my target boil amount and the mash tun has a “dry” grain bed left in it?

Add water so that you are dry when you hit your preboil volume.

Thats my SOP

Me too. And anybody who happens to be in the garage with me when it actually works out that way gets a huge high five.

Otherwise, you can collect until the gravity drops below ~ 1.01 or the Ph rises above ~5.6.

Don’t worry if you have some extra runnings in the mash tun when you reach your volume. The sweetest wort is the wort in your pot. AS you dial in your system, you will figure out how to eyeball it and get close enough. Once in a while, I come up a bit short and just dump a few gallons of hot tap water on the grain bed and collect a bit more.

Or batch sparge, easy peasy… :wink:

Do you stir, drain before you start your sparge?

in fly sparging? no.

you vorlauf until your runnings are clear, then begin running off and sparging at the same time. Ideally, you match your runoff speed to the speed at which your sparge water is running into the mash so that you maintain the water level above the grainbed.

[quote=“Dog House Brew”]Do you stir, drain before you start your sparge?[/quote]I do sort of. I vorlauf until clear and then drain most of the wort as it is very concentrated. Then I add water until it is 1-2" above the grain bed and fly sparge until my kettle is full (heating the kettle all the time).

Having extra runnings isn’t a problem, there isn’t hardly any sugar left in them anyway. Any extra in my process is collected in a bucket until the mash drains not more, then then dumped onto the driveway.