Not sure if fly sparging correctly

[jceg316]

Hey everyone, I got a whole new system a couple of months ago and have done maybe 5 brews on it. I keep getting lower gravities than I would on my older system and I think it's down to my sparging.

As I now have 50 litre SS kit, I use a pump to move liquids from one vessel to another. I usually only brew about 25 litres each time (FV volume) as I don't yet want to brew a full 50L. as an example, here's what I brewed yesterday:

5kg MO
500g light crystal malt
500g munich

used just under 18L of mash water
used 15 litres of sparge water.

Boiled for an hour, probably lost 4 litres in the boil.

this time I only had ~18L in fermenter, OG=1.049. Seems pretty low.

I used to have a sparge arm but it doesn't "fit" my new system. Instead I have an inlet tap at 9 oclock at the top of my MT (so I can incorporate a HERMS system) and I have a right angled barb with a small bit of hosing on to gently pour water onto the grain bed. I have a sheet of tin foil with holes pierced in it lying on top of the grain bed so the flow doesn't create a channel .

I think the inflow is more than the outflow as I need to top up the water in the MT so it's 2 inches above the grain bed. Once this happens does it matter that water is only being poured on on one place in the MT?

But does this all sound correct? I think I might be sparging too fast or maybe my water ratios are off?

Thanks for your help.

 

[winstonia]

It would make a difference if you're just sparging on the one spot.

How long is it taking as well?

 

[jceg316]

It would make a difference if you're just sparging on the one spot.

Why would it make a difference if there is 2 inches of water and something protecting the grain bed?

It takes about 30-45 mins, this is quicker than my old system which would be 45 mins+

 

[winstonia]

Yeah but you're just rinsing the one spot, is the tinfoil moving with gravity during your sparge? I've seen people doing it that way before

 

[jceg316]

But why is rinsing one spot bad taking into consideration what I also have mentioned? Foil isn't moving no, sems to stay put.

 

[winstonia]

It's not bad per say but I'm not technical enough to explain why you're not going to get increased efficiency since you're not rinsing the grains in an even manner

 

[jceg316]

I have researched this, asked this on another forum and it's down to speed. I need to draw off slower.

I'm making another batch this weekend so will try sparging for longer and see if my efficiency increases.

 

[TheRedDarren]

I would say it's a speed issue.
If I take a looong time (2 hours) to sparge, my efficiency goes through the roof - I hit 89% with one brew.
If I'm too quick it drops massively, down to 65/70%. These figures are with the exact same kit and almost the same recipes.

 

[simon12]

I think the problem with your sparge method is the sparge water is finding a fast channel through the grain bed so there are areas that are not getting sparged. You could try batch sparging if efficiency increases then you know its a problem with the sparge.

 

[glynb]

I agree with Simon. Sparging in one spot creates a channel that all the water will flow down so it will not touch the rest of the grain. Kind of like a rain drop on a car windowscreen. I use a pasta strainer and move it all around the mash tun whilst pouring hot water through it when I'm sparging. The temp of your sparge water may have something to do with it maybe if you are doing this already?

i got to admit, sparging for me takes a long time as like thereddarren mentioned, I like to do it slowly so I can maximise the sugar release. I do clones most of the time as I'm quite new to AG brewing so I try to aim for what the book says with regards to the O.G. I don't get it bob on a lot of the time but I get it near as I can.