Fly Sparging results question

So I've tried out a new technique to attempt to get better efficiency from my mash, and have a few questions about the results. The technique was to use a piece of aluminum foil with holes poked into it to cover the top of the mash, floating on top at first, then eventually sitting on the grains (Thanks Soulflow!). Using a hose from the HLT laid in the Mash Tun sideways (which had this swirling effect), we kept the top of the grain bed always covered with roughly an inch of 170-175 deg water. In a little bit over a half an hour, we drained to the desired collection volume 7.5 gal, keeping the inflow and outflow rate pretty much the same.


The recipe was this Oatmeal APA I came up with :
8# Maris Otter
2# Munich Malt
1# Flaked Oats
.75# Carapils
.25# Crystal 40L
.125# Crystal 120L

I pulled 7.5 gallons out at a S.G of 1.053 for pre-boiled, measured with a refractometer.
I did a 60 min boil resulting in
6 gallons of 1.058 wort for into the carboy

The questions come with the numbers:
What was my Extraction Rate?
Does it make since to have only gained .005 points from dropping 1.5 gallons?

Further,
Any tips on what I did and improving the concept?

Did you check your reading against a hydrometer? That would be a brewhouse efficiency of 95%, and are you sure about your water volumes? That would be 78% eff for 5 gal, which would be more likely unless your crush was powder.

alane1 said:

Did you check your reading against a hydrometer? That would be a brewhouse efficiency of 95%, and are you sure about your water volumes? That would be 78% eff for 5 gal, which would be more likely unless your crush was powder.

Click to expand...

I checked the O.G. with a hydro, but not the pre-boil. The readings where the same, once corrected for temp.

The crush was pretty fine, with a good bit of powder, but the hulls were pretty well intact.

I'm sure on the volumes were spot on, with the potential for error being in the actual fermentor volume. When I flamed out, I took a reading and it was 6.5 gallons, but I did not measure the sludge left in the kettle. It looked like about 3/4 gallon.

I'm not sure I totally understand the difference between Mash Eff, and Brewhouse Eff., but 95% efficiency???

So after I correct the volumes by adding back the 3/4 gallon left in the kettle, it looks like I measure my post-boil extraction rate at 87%

That's a huge increase over the 60-65% I was getting from batch sparging!
I'm sold, can't wait to taste the beer, it's bubbling away right now.

You can determine your mash efficiency by measuring your mash tun gravity at the end of the mash (First Wort) and comparing it to this graph: You should be between 90-100%



Brewhouse efficiency takes losses, volume, and extraction into account.

Methose said:

That's a huge increase over the 60-65% I was getting from batch sparging! I'm sold

Click to expand...

Now hold on there Cowboy. I've been double batch sparging for years and since getting my own grain mill, a simple Barley Crusher, I've been getting a consistent 81% efficiency, nothing anywhere near as low as 60-65% and have gotten as much as 91%. Lately I'm getting even higher than 81%, only difference being I've been using Lactic Acid to adjust my mash pH.

Just saying batch sparging in and of itself is not the reason you experienced lower efficiencies before.


Rev.

Rev2010 said:

Now hold on there Cowboy. I've been double batch sparging for years and since getting my own grain mill, a simple Barley Crusher, I've been getting a consistent 81% efficiency, nothing anywhere near as low as 60-65% and have gotten as much as 91%. Lately I'm getting even higher than 81%, only difference being I've been using Lactic Acid to adjust my mash pH.

Just saying batch sparging in and of itself is not the reason you experienced lower efficiencies before.


Rev.

Click to expand...

I'm certainly not knocking anyone's methods; I don't know enough to even start that
I've had issues with the crush in the beginning but now I have the lhbs on a much finer setting, and I see a good bit of powder in the grains.
I've not measured ph or done iodine testing of the wort but i might make that venture at some point in the future.
I was just happy with the results and how easy it was. I'm mainly looking for some consistency so I know what to expect and plan for in a recipe, and believe that I can repeat what I did (hopefully with the same results). Cheers!