How to control lautering speeds

Hi, I'm going to be trying to fly sparge for the first time soon and during a dry run with just water I'm finding it difficult to get the output from the mash tun just right. I'm aiming for about 1 qt per minute. I have a silicon hose coming from the ball valve of my mash tun into a carboy, with the end laying at the bottom. When the hose end is above the collected wort, it trickles out slow so I open up the valve to suit. After the hose end is under the surface awhile it speeds up a lot due to a siphoning effect. Should I leave the hose end up high so its a constant flow or just keep practicing with the siphoning method? Would like to know how people are doing this.

 

I'm wondering if you couldn't just use a shorter hose and be just long enough to go from you MT to your carboy with an additional 6" or so stuck down in the carboy? I mean if it works higher up then I'd go with this method considering you don't have to worry about oxidation at this point.

 

Why are you running off into a carboy and not your kettle

 

Because i only have one kettle and it sits above the mash tun for sparge water. I collect the wort in a carboy or bucket, then fill the kettle after i empty any reamaining sparge water.

 

Not understanding how you're getting a siphon from a ball valve at the bottom of an MLT. In my mind it's a simple gravity feed controlled by the ball valve. Not seeing how the hose in the wort would change anything.

 

Not sure, maybe its not siphoning..it seems like when i only crack the valve 1/2 way and there's no wort in the bucket the hose doesn't really fill up while its draining but after its underwater the hose becomes full and starts draining much faster. Maybe there is an airlock in the copper manifold when I start slow then after a time it is purged and flows properly. Im using 1/2" hose, maybe I should go with 3/8" for the lauter?

 

How much water in in the mlt during this test? I'm guessing you were batch sparking before and didn't have any trouble?

 

i have around 10 litres in the MLT. Yes I was batch sparging before with no problem but I wasn't really concerned with the flow rate either. The only other thing I have done since the last brew was soldered all the pieces of my lauter manifold together so theres no way for air to escape anymore. I might have to add a vacuum release tube to the manifold so liquid can drain easier, that might be the whole problem right there.

 

You're exactly right, you create a siphon when the hose is completely full of fluid and ends lower than the bottom of your mash tun.

You can start out by opening your ball valve all the way just for a second to fill the hose, then closing it back to half way (or a quarter way or whatever) once you've got the siphon going, if you want to proceed at "siphon speed" the whole time. But, realistically, you're still gonna have to keep an eye on things and fiddle with the flow rates to keep things balanced – the grain bed will compactify, you'll get less pressure and thus lower flow out of your kettle as the water level goes down, etc. This is why batch spargers always say fly is a PITA.