Stuck mash with lauterhexe (50% wheat)


i have a HERMS setup with a 33L mash tun + lauterhexe and the Topsflo TS5 15PV pump. I brewed several batches with this setup (100% barley malt) without any issues. But yesterday we brewed a Belgian Wit where 35% of the grain bill was flaked wheat, 14% wheat malt and only 51% barley malt.

I started with a 10 minute protein rest at 50C and slowly raised the temp to sacharification temperature 65C. Soon after I started the recirculation I noticed a degradation of flow rate. I stped the recirculation a few times and stirred the mash, it helped but only for a short time. I also tried to slow the flow rate at the output of the pump with a ball valve to decrease the “suction” on the grain bed but this did not helped either. After 30 minutes the flow stopped almost completely. I tried to add wheat husks but they were floating on the top of the mash (I could not get any rice hulls here in Slovakia). We were quite desprate so we tried to move the lauterhexe on the bottom of the mash tun with a long spoon and it helped a bit, the flow increased, but only for a few seconds.

Do you guys have also this king of stuck mashes with a lauterhexe? I brewed this recipe before, but with a false bottom instead of lauterhexe and did not had any issues then. The only other difference is that when I brewed it first time I did a 30 minute beta - glucane rest at 42C. Could omiting of this step cause the stuck mash?

I am now considering to switch the lauterhexe for a false bottom and use the lauterhexe in boil kettle as a hop filter…

Hi There
There might be a chance that you have remaining starch in your mash which may clog the lauterhexe. You could test that with a potassium iodide solution in water, that will turn blue if you have remaining starch. I would recommend using a false bottom rather than lauterhexe or maybe combined, with the lauterhexe underneath the bottom. Try visiting the web page Brewers Friend they got a lot of useful information and practical experience.

Cheers Ken