I made one all grain batch so far and am a little confused about one thing in particular. After letting the grains soak in the cooler at the desired temperature for the desired time and you vorlauf. Do you drain all the water off of the grain before fly sparging or do you fly sparge on top while draining the first soak?? Also when adding the fly sparge water at the desired temperature, is it important what the temperature of the grain bed is?
Fly sparge water temperature?
- Thread starter martyjmc
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There are two ways to do this, but here is the most common. After the mash, you add enough boiling water to get the entire grainbed up to 168. For me, that is usually about 2 gallons in a 10 gallon batch. Then, volauf, and start draining. Add the sparge water (at 170 degrees) at the same rate you drain the MLT, slowly, so that you always have at least an inch of water (or more) above your grainbed.
If you're not doing the "mash out", you could add the hotter sparge water to the MLT but make sure the grainbed never gets above 168.
For those who can heat up their MLT with recirculation or direct fire, they can just bring the entire works up to 168 and then start sparging with 168 degree water.
I hope this explanation helps and doesn't make it even more confusing.
Yooper said:
This definitely helps! Thank you very much! I have read quite a bit and never thought about this until I brewed my first all grain batch. I brew five gallon batches with ten gallon HLT and MLT igloo coolers and a ten gallon brew pot. So I will need to figure out how much boiling water it will take to get me at 168. Thanks again....HBT has been a tremendous help for me and everyone is very helpful and knowledgeable.
And if you don't hit 168, that's ok. The idea is twofold- to denature the enzymes to lock in the "profile" of the beer as well as to make the sugars more soluble.
But if you hit, say, 162, with the mash out, it's really not a big deal. A good way to preserve the profile of the mash is to start the runnings onto boil as you run them off and they'll get to 168+ quickly that way. So if you don't do a textbook perfect mash-out, it's still perfectly fine!
Yooper said:
Ok. One more question? Do I just keep adding 170 degree water, keeping it an inch or more above grains until I reach my desired volume in the brew pot or estimate the correct amount and let the grains run dry?
You'd keep adding the water, until you reach your boil volume.
I do know some that have let the grains run dry, but that doesn't really work that well.
The reason is that fly sparging (also called continuous sparging) works by the properties of diffusion. The water "pulls" out the sugars as it flows through the grainbed, taking the sugar to the fresh water. The reason this works is that the movement of a fluid from an area of higher concentration is always to an area of lower concentration. So, the higher concentration of sugar will seek equilibrium and move to your water and that's where the wort gets its sugar. We say sparging is "rinsing" the grain, but it's really not rinsing as much as diffusing. Draining the MLT will work in the sense you'll still get some diffusion, but not as well as continuing to replace the water as it lowers. Doing that also avoid channelling in the grainbed.
Yooper said:
Thanks! It makes sense. This will help make me more confident on my next batch. I just started adding the 170 water to the mash last time and started questioning myself and adding hotter water all of a sudden trying to get the mash temp up but ultimately screwed it up.....hope it turns out ok. It's fermenting.
If you are fly sparging, you do not want to drain off your first runnings before starting the sparge, and yes, you do want to keep the grain temperature under 170F.
If you are fly sparging with 170F water after a 152F mash, you won't get the grain bed temperature anywhere near 170F.,
When I started doing a mash out, my efficiency increased by 10% I thought that this was due to the higher mash temperature ( upper 160's as opposed to mid 150's). I now think that the efficiency increase was due to the stirring in of the mash out water.
I completely agree with this.
I have to disagree with Yooper on this point. If the gravity of the sparge drops below a certain value (in my case that's 1.008), then I need to stop adding any more sparge water to avoid tannin extraction. If the gravity drops to 1.008, I stop adding sparge water and collect whatever I can. If I end up short on my pre boil volume, then I just top it up with water.
If I continue to sparge with a gravity below 1.008 then I collect excessive tannins and the beer will end up tasting quite unpleasant.
-a.
ajf and I don't actually disagree on this- I do the same. But unless you have a fairly small grain bill (say, making a 1.039 beer), oversparging is rarely an issue. I do stop if my runnings hit 1.010 or below, but that's happened to me only a couple of times. I just forgot about this, in my explanation.
ajf is right, and you would definitely do well to keep this in mind.
Not really. If you have a moderate sized grainbill, maybe check it when you have another gallon or so to go. If it's higher than like 1.014-1.018 or so, you should be perfectly fine. If it's 1.012, then you're going to want to want to make sure you don't drop too much more.
Everybody's system is different.
If I am brewing a brew with an OG > 1.060, I can sparge, keeping the water above the grain bed until I have collected the required pre boil volume.
For a brew with an OG > 1.055 and < 1.060, I need to stop adding sparge water before I have collected the required pre boil volume, but I don't need to top off with water.
For a brew with an OG < 1.055, I need to stop adding sparge water when the gravity of the runnings drops to 1.008, and then top off with extra water in order to get my required pre boil volume.
These are guesstimates, and may be slightly off, but they are pretty accurate for my system.
Your system may be very different than mine.
As far as continuously monitoring the gravity of the runnings, as Yooper said, you don't need to do it at the beginning of the sparge, it's only towards the end that it becomes important. I use a refractometer to gauge the gravity of the runnings which is quick, easy, and accurate. You could also use a taste test. If the runnings taste sweet, you can continue sparging. If the runnings no longer taste sweet, then you may want to think about stopping the sparge.
This is obviously not as accurate as taking a gravity reading, but if you try it for a few brews and concentrate on determining the gravity by the sweetness of the wort, it works pretty well. (This was what I used to do before I got a refractometer.)
-a.
If I am brewing a brew with an OG > 1.060, I can sparge, keeping the water above the grain bed until I have collected the required pre boil volume.
For a brew with an OG > 1.055 and < 1.060, I need to stop adding sparge water before I have collected the required pre boil volume, but I don't need to top off with water.
For a brew with an OG < 1.055, I need to stop adding sparge water when the gravity of the runnings drops to 1.008, and then top off with extra water in order to get my required pre boil volume.
These are guesstimates, and may be slightly off, but they are pretty accurate for my system.
Your system may be very different than mine.
As far as continuously monitoring the gravity of the runnings, as Yooper said, you don't need to do it at the beginning of the sparge, it's only towards the end that it becomes important. I use a refractometer to gauge the gravity of the runnings which is quick, easy, and accurate. You could also use a taste test. If the runnings taste sweet, you can continue sparging. If the runnings no longer taste sweet, then you may want to think about stopping the sparge.
This is obviously not as accurate as taking a gravity reading, but if you try it for a few brews and concentrate on determining the gravity by the sweetness of the wort, it works pretty well. (This was what I used to do before I got a refractometer.)
-a.
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