ph0ngwh0ng

Recipes 

__________________
Primary: Air
Secondary: Air
Bottle conditioning: Leftovers Irish Red Ale, Saint-Francois Witbier
Drinking: Cheapo Porter
Planning: Saint-Francois Witbier Unhopped, BM's Centennial Blonde

Bobby_M

Recipes 

There is no hard evidence. No one has done any experiments that I'm aware of that test for differences. Both sparging techniques have their pros and cons and it is usually the equipment setup and brewer's skill that exploits either of them. Anectodotally, fly sparging takes a bit more attention to detail in order to maximize efficiency (most importantly in lauter tun design and sparge speed). Following a few basic steps in fly sparging will usually get the job done.

I'm personally aiming to fly sparge a few batches so that I can more conclusively weigh in on the matter. It's just hard to push myself to do it because 90% efficiency batch sparging has been good to me.

__________________
Sightglasses and more at BrewHardware.com | All Grain Primer Still Available too!

menschmaschine

Recipes 

I think it's actually a fairly simple scientific concept. All other factors aside (water quality, mash tun design, etc.), think about what you're trying to accomplish. The goal here is to get sugars, proteins, and other good wort compounds off of the grain. With continuous sparging, there is a constant down-flow of sparge water relatively uniformly distributed through the grain bed. All of the sugars and other compounds have a good chance of getting rinsed off the grain and ending up in the kettle. In batch sparging, there are typically 2 batches of sparges. The water mixes up all the grain and does a fairly good job of loosening up sugars, etc. into solution. However, when it is drained, some of these sugars, etc. can get "caught" up in the grains and not make it to the kettle. This is why a double batch sparge works a lot better than a single batch sparge... because you're loosening up these compounds that didn't make it the first time and getting them back into solution and into the kettle.

With the single minded goal of getting the most out of the grain, continuous sparging is just going to get more (with the right system). The negatives are that there is a risk of over-sparging (tannin extraction), but this is really water dependent. If your sparge water has a relatively low pH, there isn't much risk of this. Another negative is time, it's generally recommended to fly-sparge for an hour or more. Many brewers don't like this extra time and are willing to sacrifice a few points of efficiency for the time saved.

Some batch spargers claim to get practically as high efficiency as fly-spargers, but while that is possible, I can also say that I've fly-sparged in 30 minutes (12 gallon batch- open valves to close) and still got over 90% efficiency. So these are anomalies and the majority of brewers fall into the positives and negatives mentioned above. One thing to note, is that most commercial breweries do continuous sparging or some related method. Their main goals are cost cutting and quality, both of which tend to work out for them (personal beer tastes aside) with continuous sparging.

__________________
END TRANSMISSION

david_42

Recipes 

The few people I know who have done both under carefully controlled conditions report no real differences in the final results. Commercial brewers fly sparge, because it is optimal use of the equipment volume. Batch sparging requires a tun volume about 50% larger than the grain bed, fly sparging you can use nearly 100% of the tun.

bigben

Recipes 

there's a reason you haven't found hard evidence of the final results... Because there isn't any

Theoretically, all things being equal, fly spargeing will yield higher efficiency. Fly spargeing may also increase the risk of leeching tannins from the grains but I don't remember ever hearing anyone complain about that.

Batch sparging can save you time. Also "no sparge" has been rumored to produce a richer,maltier beer at the expense of efficiency. But again, no hard facts.

Bobby_M

Recipes 

The moral of the story is if you want scientific evidence, you'll probably have to buckle down and do the experimenting on your own. Keep good notes and post your results for review.

I agree with David in that commercial brewers almost always use fly sparging but it is hardly a valid arguement for or against it in the context of homebrewing. It would be a bit silly building a stirring mechanism on a 15 barrel MLT that would acheive the same effect as our mash paddles are capable of upon each batch sparge infusion.

It seems to me that most fly spargers get about 85% plus efficiency when they design their tuns correctly and take their time sparging. Most batch spargers get about 70% following the rules loosely. There are always exceptions. A few fly spargers in my club told me they get 75% consistently. I get 90% batch sparging (as do others).

If you were to design a fly vs batch experiment, what hypotheses would you be most interested in testing for (afterall there is no "best" at such a high level)? Efficiency? Flavor? Long term stability?

__________________
Sightglasses and more at BrewHardware.com | All Grain Primer Still Available too!

wildwest450

Recipes 

__________________
My dream brew shed build Beware of Miss Information, she's everywhere

Boerderij_Kabouter

Recipes 

Do what is easier for you. On our scale efficiency really doesn't matter. I mean if your batch costs an extra dollar in grain, are you really going to notice. I fly sparge because it made more sense to me when I started brewing and I have stuck with it. If you have a system that works and yields good results why change it. Unless you get bored or curious, just stick with what you are doing.

Bobby_M

Recipes 

I propose not to let this thread get out of hand. This is one of those topics where a relatively new memeber posts and then HBT regulars bring it to 75+ posts strong and the OP chimes in once or twice (if that). He should obviously chime in to explain what the intent was. Frankly, given the generic nature of the OP, this should be in the debate forum. If there's some specific aspect of either method that is in question, that's a different story.

__________________
Sightglasses and more at BrewHardware.com | All Grain Primer Still Available too!

Saccharomyces

Recipes 

I used the hybrid fly sparge technique for a couple of big beers and I got 83% and 86% with 16 and 14 pounds of grain on a 5 gallon batch. The rest of the time I do a double batch sparge and consistently get 78-82% efficiency. I find the batch sparge to be simpler and more RDWHAHB, although it isn't necessarily quicker since I do not yet have a HLT (I heat my two sparge infusions separately).

Both techniques will yield good efficiency if you dial in your process.

In batch sparging a fine crush is key to getting good efficiency, since you don't get complete diffusion with a coarse crush. If you don't have a mill, have your LHBS run the grain through the mill twice. In fly sparging you don't want to overcrush the grain or you risk a stuck sparge, and will end up effectively batch sparging in slow motion.

__________________
Dos Amigos Brewing

[How to Calculate Mash Efficiency | Do I Need a Yeast Starter? | My Ghetto Fermentation Chamber | Twitter | 6 Gal. HDPE Fermenters | Slanting Yeast | No Sparge Brewing]