Fly Sparging, How long?

Just about everything I've read says that it takes about an hour to sparge a 5 gal batch but mine only takes about 15 min if that. I have a rotating sparge arm that I made out of 1/2 inch copper tubing and I use a March pump to push the water through the arm. Even if I regulate the flow as slow as I can to just get the arm to barely move it's still a fairly quick process. Could it be that my laughter tun is just a good design that allows the wort to flow freely or am I likely leaving behind lots of fermentables? My efficiency seems like it could be a little better but I don't think it's too bad. If I'm brewing a recipe that says the target OG should be 1.054 I'll probably hit between 1.054 and 1.051. I know there are lots of thing that can result in poor effiency other than sparging techniques.

When I fly sparge I make it take 1 hour to complete. It should not take 15min... a lot of ppl will chime in and say just batch sparge, but I like fly sparging. My method is not exact but ill get 78%-86% depending. I use no fancy equipment just a 10gal cooler, a strainer and a 2L pitcher to put my 170deg water in with. Works perfect, no channeling or drilling. I drain 1 gal every 10min or .5gal every 5 min. It works real good with no extra equipment and very little work.


But to answer your question, 45-60 min to fly sparge. And at the end of your sparge, your wort should look like water but have no water left in your tun for best efficiency.

Hope this helps a little.

I am somewhere in between the two of you. My fly sparge of a 5 gallon batch usually takes about 30-45 minutes (my 10 gallon batch took longer). It sounds like you need to adjust the flow coming out of the mash tun. If you slow that down, the flow will take longer. If necessary, you could shut off the sparge water periodically to keep the water level a bit above the grain bed but not too high.

Depending on the grain bill, I usually end up mashing with about 4 gallons of water and sparging with another 4. I only open the mash tun valve a little bit to keep the flow nice and slow. When I start sparging, I put a spaghetti strainer on top of the mash tun - the handles prevent it from falling in - and then lay a couple of paper towels into the strainer. Then I start pouring sparge water into the strainer, keeping an eye on the water level. I try to not let it hit the top of the grain bed.

When I have about two gallons of water left, I remove the strainer, close the valve, dump the rest of the water in, stir the crap out of it, vorlauf and drain the rest.

I get pretty good efficiency.

I guess it depends on how much efficiency you want to achieve and how you value your time. If I sparge for about 45 minutes, I can achieve 85% efficiency. If I cut it to 20 minutes, I get about 72%. I'd rather throw a few extra pounds of malt in my mash and save the 25 minutes.

So why exactly does a longer sparge resualt in better effiency? Does the water just have more time to dilute and extract the fermentables?

When sparging you are rinsing the converted sugars out of the grain. A longer sparge will rinse more sugars out.

Can sparging too long hurt efficiency? My last two brews I have fly sparged over 75 min, and my efficiency has dropped almost 10 points. Unless my crush has not been as good from my LHBS, I have not changed anything else in my process. Might be going back to 60 min sparges.

Long sparges should not drop efficiency. Conversion efficiency (how well the enzymes did their job) should be complete before you even start to sparge. Your brew house efficiency should improve with longer sparges since you have longer enzyme contact time, but that may not be desirable.

If your sparge water is hot enough (mash out temps), then sparging should gradually stop enzyme activity....it will take awhile for that hot sparge hot to permeate the grain bed and it's cooling as it works it's way down.