do I need to use rice hulls?

[berkeleybrewer]

So I tried brewing a really straight forward dry stout for St. Patty's day and ended up getting a stuck sparge. The malt bill was this:

Grains:

Maris Otter - 62%
Flaked Barley - 23%
Black Barley - 15%

(grains as a percentage of overall grain bill because I brew 2.75 gallon AG batches)

I hit my temperature numbers for a 154 F mash and was all set to sparge. Unfortunately, I could not collect any run-off. I tried adding sparge water, re-stirring, blowing back up through the tube, but none of it worked. So without the proper tool to reach into the 160+ degree wort I had to dump it

Is the flaked barley responsible for my stuck sparge? I didn't think to use rice hulls? Could this be the issue or is it an issue with my 5 gallon igloo mash tun set-up? My igloo cooler has a false bottom and I saw that once the wort had been dumped that a shit load of grain had gotten underneath my false bottom and blocked wort from flowing underneath the false bottom and through the valve outlet.

Thanks for any advice.

[captain carrot]

I look at rice hulls as cheap insurance. If I'm using 25% to 50% wheat or flaked barley I'll throw in a half pound to a pound of rice hulls. I'd rather spend the money on rice hulls than deal with the aggravation of a stuck mash or low efficiency.
Hope this helps.

[berkeleybrewer]

Thanks Captain, I'll add rice hulls when I re-brew. Wish I'd thought to add them since I already have some on hand.

[brewinhard]

If you say you got a bit of grains under your false bottom, then rice hulls probably wouldn't have helped that. How are you doughing in? Do you add your water first, then add a little grain and stir, then a bit more grain, and stir? Do you open your cooler valve slowly at first to prevent collapsing the grain bed?

Rice hulls would help with the flaked barley, providing you didn't get a lot of grains under the false bottom to clog the outflow. You probably could've dumped the whole mash into your kettle, then clean and reset the false bottom. Then dump your mash back into the cooler and try again.

[berkeleybrewer]

Brewinhard, you make a good point. I dough in by adding water and then adding grain and stirring, but when I opened the valve just barley and nothing came out, I opened it further and further and probably collapse the grain bed.

Next time I won't panic and will just dump all the contents in the tun into my kettle and try to unclog the false bottom.

[maxwell]

Next time, you can try to avoid dumping it by pouring the mash into your kettle and heating to mash-out temp (168 F). When I get a stuck mash, my usual procedure is to blow into the manifold to unclog it, then t add hot water to increase temp, then stir in more hydrated rice hulls, and try to repeat the vorlauf. For a recipe with 20% flaked barley I usually put in at least a half pound of rice hulls at the beginning of the mash.

[baltobrewer]

You're likely culprit is the flaked. That will get gummy if left to its own devices. m I've gotten to the point that I use about a half pound of rice hulls in every batch. I put them in first, then dough in on top of them. They collect around the screen, and my runoff is never slow. Might want to try it. Great cheap insurance, and shortens the brewday as well...