When I converted to this simple fly sparge method I picked up 8 points in efficiency. No extra equipment needed
just a change in the method for adding / draining wort from the mash tun. This method was discussed in a recent issue of BYO, but these are my own random notes.
In both cases
the approach to the vorlauf is the same.
Difference between batch and fly.
Batch Sparging Uses a method of stirring and rinsing the grains several times to wash out the sugars. We drain the wort. Add more water. Stir. Drain the wort and repeat until we get our desired pre-boil volume.
Fly Sparging Relies on a squeegee method of washing the sugar out of the grain bed. The grain bed may be stirred once just before sparging begins. Then the wort is drained very slowly and hot water is continually added to the top of the tun to maintain 2-3 inches of liquid over the grain bed. This hot clean water slowly pushes the sugar water down and out through the drain valve. By not stirring the grains, you are not re-suspending sugars in the grain bed and the rinse is (in theory) more complete.
Fly sparging does not require sparge arms, drip rings or other apparatus to get the desired effect. Though a hybrid approach may be somewhat less efficient than using a sparge arm
it is also much quicker. Hybrid Fly sparging is a nice compromise between the simplicity of batch sparging and the extreme efficiency of fly sparging.
Technique:
If you use a march pump to deliver your sparge water
you can adapt your system to this technique very easily.
For me
Im a sauce pot kind of guy.
- Raise your sparge water to 185 degrees (well save the debate for exact temps for another time).
[*]Vorlauf your first few quarts of runoff like normal. (I advise a very slow vorlauf to prevent grain bed suction and stuck sparges)
[*]When youre ready
begin draining the wort very slowly into your kettle. (My valve is usually opened about 25%)
[*]Immediately begin ladling in hot water to the top of your mash
careful not to disturb the bed of grains below the waters surface.
[*]I usually will lay the pot into the water and then gently tip it to fold the water in rather than pour it.
[*]Continue to ladle in your sparge water at the same rate it is flowing out. (You are now fly sparging).
[*]If you need to pause to refill you hot liquor tank
.simply close your valve until you are ready to resume.
A trick I like to employ is that once the kettle is filled up to my
post boil level
I draw a sample
cool it and take a gravity reading. Then I continue to fill the kettle. This gives me a good reading about how aggressive Im going to need to be with my preboil volume to hit my target OG.
Since you cant be exact with how much runoff youre going to have
once I get to my preboil level, Ill drop the drain hose into a separate bucket to catch the excess. In theory, if my rinse has been effective, this excess should have little to no sugar value and can be discarded.
This process is a bit longer than a standard batch sparge. But it is substantially quicker than a full fly sparge.
A few notes:
- Since your grain bed essentially resting longer with this method
youll want to adjust your rest times accordingly. My first few beers with this method were bigger than I anticipated
but the longer rest time meant they attenuated lower as well.
- The slower you are in this process, the better your efficiency.
- For round coolers, keeping your manifold or other device in the center of the grain bed will prevent water from finding the course of least resistance (the cooler wall), which will lower your efficiency.
- Remember that the point here is that the clean hot water on top
is pushing down on the denser sugar water below and plunging it out the bottom.
Anyway. You dont need to buy any equipment to give it a try. See if it helps your Brewhouse.
The sketch below is my terrible attempt to illustrate the effect of a hybrid fly sparge.
View attachment 7128
Here's my "bucket" in action:
[ame]
