stuck sparge

[Arbe0]

I have a 6 gallon electric pot that recalculates from the bottom to the top like the one on Brausupply.com (unibrau BIAB system). sometimes I get a stuck sparge and I don't think it is from Grains, in that the grains are in a bag. This is just like a BIAB with a 6 gallon pot that I can make 3 gallon brews with.
Is it possible that it happens because of an air bubble or air lock that keeps the wort from recycling, and if so how would I fix it?

 

[kh54s10]

I don't use pumps but have read that you can get air in the line that will stop them from working. One solution is to make sure the pump is low so that the wort flows down to the pump head. It also could be something blocking the line. I have read in recycling BIAB systems where enough grain debris got into the system to block it.

Try to make sure that the pump head has wort in it. If there is air it might just spin. I don't know the best way to do that. Maybe install a little purge valve at the lowest point in the system and open until wort comes out.

 

[Arbe0]

everything works fine for about 15-20 minutes then the wort just stops coming from the pot. The pump is a lot lower than the pot, and I make sure the pump has wort in it before I start it up, then open the valve on the out side to start the flow.

 

[nettekdl]

Have you tried throttling down your recirculation rate?

 

[RM-MN]

Your problem is in the recirculation. Normally when BIAB brewing, the bag of grains sits in the water and when you pull it out the liquid drains because there are pores in the bag, lots of them, so if a few plug up with grain particles it doesn't matter. When you recirculate you pull the small grain particles from the center of the mash and some of the pores plug up but you don't notice because you have lots of pores so you keep recirculating until finally you get all the pores plugged and recirculation stops. To avoid this you either crush much coarser and suffer the loss of efficiency or you quit recirculating.

 

[Arbe0]

thanks all for the feedback. I will try to keep the flow lower, get a new BIAB bag and try again. Seems like it worked great for about a year then I started having this problem. Could be that when I crush my grains at the LHBS and they have it set closer then they used to. MMM time to get my own mill.