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General Category => All Grain Brewing => Topic started by: redzim on August 31, 2010, 11:54:48 AM

Title: rice hull percentage
Post by: redzim on August 31, 2010, 11:54:48 AM
Can't seem to find a quick answer to this: what percentage of the grain bill (by weight) are you guys using to add rice hulls? I batch sparge, and a couple recent batches with slow/stuck sparges (esp. one that was 25% wheat and 25% rye that was my Worst. Sparge. Ever. ) have got me thinking that rice hulls could help out.

thanks
red
Title: Re: rice hull percentage
Post by: Mikey on August 31, 2010, 02:13:07 PM
0% here. ;D
Title: Re: rice hull percentage
Post by: mrcceo on August 31, 2010, 02:24:47 PM
Increase your water to grain ratio in your mash. You can go up to 2:1.
I usually keep mine between 1.5 to 1.75 to 1.
Title: Re: rice hull percentage
Post by: ryang on August 31, 2010, 02:28:12 PM
I had a 5gal batch of wit with 3lbs barley 4lbs wheat along with 3lbs of flaked wheat and oats.  I used a one pound bag of rice hulls.  I think I'd add more next time.  It didn't get stuck, but it was very slow.
Title: Re: rice hull percentage
Post by: theDarkSide on August 31, 2010, 02:32:04 PM
I just did an oatmeal stout this past weekend and use 1/2 lb of rice hulls.  The wort was pouring like oil and never stuck once.  Would it have stuck with the rice hulls?  I don't know but didn't want to take the chance with the flaked oats.
Title: Re: rice hull percentage
Post by: redzim on August 31, 2010, 02:46:33 PM
Increase your water to grain ratio in your mash. You can go up to 2:1.
I usually keep mine between 1.5 to 1.75 to 1.


I already run between 1.75 to 1 and 2.0 to 1.
Title: Re: rice hull percentage
Post by: denny on August 31, 2010, 03:30:31 PM
The generally recommended amount is "a handful".
Title: Re: rice hull percentage
Post by: mrcceo on August 31, 2010, 03:39:57 PM
Increase your water to grain ratio in your mash. You can go up to 2:1.
I usually keep mine between 1.5 to 1.75 to 1.


I already run between 1.75 to 1 and 2.0 to 1.

How is your crush? Do you have a lot of intact husks?

Second, and I'll probably catch some heat for this from Denny but if your using a braid in he bottom of your mash tun you may want to consider increasing the length and at the same time stretch it out a little to open the weave a bit.  I got 2 stuck sparges back to back and this solved the problem. Even with 50% wheat it flows like a champ.
Title: Re: rice hull percentage
Post by: denny on August 31, 2010, 03:51:14 PM
Well, pragmatically speaking, if that solved your problems, that's the right thing to do.  But I have to admit that I've never had a problem with a stuck runoff, and most of the time a shorter braid works better.
Title: Re: rice hull percentage
Post by: mrcceo on August 31, 2010, 04:24:00 PM
Well, pragmatically speaking, if that solved your problems, that's the right thing to do.  But I have to admit that I've never had a problem with a stuck runoff, and most of the time a shorter braid works better.

Maybe the weave is closed to much and he needs to open it up a little more.
Title: Re: rice hull percentage
Post by: majorvices on August 31, 2010, 05:48:23 PM
0% here. ;D

+1 - even on 60% wheat.
Title: Re: rice hull percentage
Post by: tschmidlin on August 31, 2010, 06:22:23 PM
I'll throw in a pound when doing a batch with a lot of wheat.  I don't really know how much it helps, I've never tried the same recipe without the rice hulls.
Title: Re: rice hull percentage
Post by: redzim on August 31, 2010, 06:52:02 PM
Well, pragmatically speaking, if that solved your problems, that's the right thing to do.  But I have to admit that I've never had a problem with a stuck runoff, and most of the time a shorter braid works better.

Maybe the weave is closed to much and he needs to open it up a little more.

I have the 12" Bazooka screen, got it from NB about 2 years ago... it certainly looks like a tighter weave/mesh than the pix on Denny's site.  I might try to stretch it....   I've ordered a bit of rice hull and since I have a good feel for how my system drains on a 100% barley grain bill, I'll add half a pound or so to my next batch and see if it speeds it up at all, if that helps I'll use it on my next wheat beer.
Title: Re: rice hull percentage
Post by: tschmidlin on August 31, 2010, 09:23:39 PM
most of the time a shorter braid works better.
Can you explain this too* Denny?  How short are we talking about?  How long should the braid be for that 70 qt cooler we were talking about in the other thread (http://www.homebrewersassociation.org/forum/index.php?topic=3462.msg39506#msg39506)?  I know I said I got it to use as a cooler and not a mash tun, but as long as I have it I might as well try it out, right? :)

*And go and answer the other thing I asked you about. (http://www.homebrewersassociation.org/forum/index.php?topic=3407.msg39986#msg39986)
Title: Re: rice hull percentage
Post by: majorvices on August 31, 2010, 09:27:56 PM
FTR I have the SS mesh braid from Lowe's in my small MT and a Bazooka screen in my big MT and don't have a problem with either. The run off is a little slower, but not so much that it causes a problem.
Title: Re: rice hull percentage
Post by: denny on August 31, 2010, 10:01:10 PM
most of the time a shorter braid works better.
Can you explain this too* Denny?  How short are we talking about?  How long should the braid be for that 70 qt cooler we were talking about in the other thread (http://www.homebrewersassociation.org/forum/index.php?topic=3462.msg39506#msg39506)?  I know I said I got it to use as a cooler and not a mash tun, but as long as I have it I might as well try it out, right? :)

I've heard from a lot of people who had problems with the braid floating (I don't consider that a problem, but some do), or getting tangled if it's too long.  One person even told me that shortening the braid increased his efficiency, although I have trouble understanding why that would be.  In my experiments, I've used braids from 3" to the length of my cooler with equal results from all of them.  The only reason my current braid is the length of my cooler is that it's the last length I tried and I was too lazy to change it.  Keep in mind that all of the draining happens at the cooler outlet, so a longer braid doesn't really provide more "space" for the wort to run through.

*And go and answer the other thing I asked you about. (http://www.homebrewersassociation.org/forum/index.php?topic=3407.msg39986#msg39986)

done!
Title: Re: rice hull percentage
Post by: majorvices on August 31, 2010, 10:19:48 PM
My braid is probably about 8-9 inches long. I tied it in a knot and this keeps it from floating and I have no issues with run off.
Title: Re: rice hull percentage
Post by: Mikey on August 31, 2010, 10:50:39 PM
I have 2, 12" pieces of 1/2" braid. Short didn't work for me, but this setup never sticks.
Title: Re: rice hull percentage
Post by: mrcceo on September 01, 2010, 12:35:03 AM

Keep in mind that all of the draining happens at the cooler outlet, so a longer braid doesn't really provide more "space" for the wort to run through.


But a longer braid does provide more surface area to gather and channel the wort to the outlet which could make a difference with compressed grain beds and gummy grains like wheat and rye.

Just a thought
Title: Re: rice hull percentage
Post by: tschmidlin on September 01, 2010, 02:34:33 AM

Keep in mind that all of the draining happens at the cooler outlet, so a longer braid doesn't really provide more "space" for the wort to run through.


But a longer braid does provide more surface area to gather and channel the wort to the outlet which could make a difference with compressed grain beds and gummy grains like wheat and rye.

Just a thought

That's what I was thinking too, but it sounds like it's not a problem for these guys.

Do you tilt the mash tun a little bit to aid in the wort flowing to the channel?
Title: Re: rice hull percentage
Post by: mrcceo on September 01, 2010, 03:27:22 AM

Keep in mind that all of the draining happens at the cooler outlet, so a longer braid doesn't really provide more "space" for the wort to run through.


But a longer braid does provide more surface area to gather and channel the wort to the outlet which could make a difference with compressed grain beds and gummy grains like wheat and rye.

Just a thought

That's what I was thinking too, but it sounds like it's not a problem for these guys.

Do you tilt the mash tun a little bit to aid in the wort flowing to the channel?

I will tilt it after the final sparge.  Since the outlet is just above the bottom of the tun it helps to get out the last bit of wort.
Title: Re: rice hull percentage
Post by: denny on September 01, 2010, 03:36:10 PM

Keep in mind that all of the draining happens at the cooler outlet, so a longer braid doesn't really provide more "space" for the wort to run through.


But a longer braid does provide more surface area to gather and channel the wort to the outlet which could make a difference with compressed grain beds and gummy grains like wheat and rye.

Just a thought

But it really doesn't channel it to the output since the braid is open.  The wort merely runs through it.
Title: Re: rice hull percentage
Post by: Mikey on September 01, 2010, 04:09:09 PM

Keep in mind that all of the draining happens at the cooler outlet, so a longer braid doesn't really provide more "space" for the wort to run through.


But a longer braid does provide more surface area to gather and channel the wort to the outlet which could make a difference with compressed grain beds and gummy grains like wheat and rye.

Just a thought

But it really doesn't channel it to the output since the braid is open.  The wort merely runs through it.

If a longer perforated tube isn't an advantage, then a sewer system wouldn't need but a couple of feet of lateral line. Same thing only backwards..
Title: Re: rice hull percentage
Post by: tubercle on September 01, 2010, 04:09:39 PM
 I have a ~4" braid connected to the outlet with a ~4" piece of 1/2" copper pipe w/ hacksaw slots on the tail end. Stops the floating issue and if the wort wants to go through the pipe slots or braid or a combination of the two, then help yourself. Never had a problem of any kind with this setup. My cooler is red w/blue stripes too. I like the best of both worlds.
Title: Re: rice hull percentage
Post by: denny on September 01, 2010, 04:11:56 PM
If a longer perforated tube isn't an advantage, then a sewer system wouldn't need but a couple of feet of lateral line. Same thing only backwards..

Based on my experience, I don't know if that's a valid comparison.
Title: Re: rice hull percentage
Post by: redbeerman on September 01, 2010, 04:14:00 PM
The generally recommended amount is "a handful".

Or about 4 oz. ;)  depending on the size of your hand.
Title: Re: rice hull percentage
Post by: mrcceo on September 01, 2010, 04:17:25 PM
If a longer perforated tube isn't an advantage, then a sewer system wouldn't need but a couple of feet of lateral line. Same thing only backwards..

Based on my experience, I don't know if that's a valid comparison.

The grain bed compresses around the braid forming what amounts to a pipe with perforations. The more perforations which are provided by the longer braid /pipe the more wort that can be filtered as the grain bed compresses or as the filtering slows due to clogging of the braid by fines or sticky material.  If all goes right you wouldn't need a long braid but when adding wheat or rye the additional length gives you an added safety factor.
Title: Re: rice hull percentage
Post by: bluesman on September 01, 2010, 04:18:49 PM
I've also heard (I believe it was Gordon Strong) of cutting channels in a grid pattern in the grain bed to facilitate better channeling.  
Title: Re: rice hull percentage
Post by: Mikey on September 01, 2010, 04:21:10 PM
I'm not saying a short tube won't work, but the added length is a nice safety factor. Just stands to reason that the more surface area your filter has, the faster it will allow the runnings to flow and the less likely it will clog.
Title: Re: rice hull percentage
Post by: denny on September 01, 2010, 04:24:15 PM
I'm not saying a short tube won't work, but the added length is a nice safety factor. Just stands to reason that the more surface area your filter has, the faster it will allow the runnings to flow and the less likely it will clog.

But why wouldn't the wort just flow in one side and out the other?  Why would it follow a perforated tube with so much open surface area?
Title: Re: rice hull percentage
Post by: mrcceo on September 01, 2010, 04:29:42 PM
I'm not saying a short tube won't work, but the added length is a nice safety factor. Just stands to reason that the more surface area your filter has, the faster it will allow the runnings to flow and the less likely it will clog.

But why wouldn't the wort just flow in one side and out the other?  Why would it follow a perforated tube with so much open surface area?

Because the grain bed compresses forming resistance to backflow.
Title: Re: rice hull percentage
Post by: denny on September 01, 2010, 04:30:22 PM
Hmmmmm....gonna have to think about that.
Title: Re: rice hull percentage
Post by: Mikey on September 01, 2010, 04:44:53 PM
I'm not saying a short tube won't work, but the added length is a nice safety factor. Just stands to reason that the more surface area your filter has, the faster it will allow the runnings to flow and the less likely it will clog.

But why wouldn't the wort just flow in one side and out the other?  Why would it follow a perforated tube with so much open surface area?

Good point, but the majority of it will take the path of least resistance and that's down the middle of the tube.
Title: Re: rice hull percentage
Post by: beveragebob on September 01, 2010, 11:53:59 PM
I'm with DC on this one. I go by handfulls usually 3-5 has always worked for me
Title: Re: rice hull percentage
Post by: denny on September 02, 2010, 03:45:42 PM
I'm not saying a short tube won't work, but the added length is a nice safety factor. Just stands to reason that the more surface area your filter has, the faster it will allow the runnings to flow and the less likely it will clog.

But why wouldn't the wort just flow in one side and out the other?  Why would it follow a perforated tube with so much open surface area?

Good point, but the majority of it will take the path of least resistance and that's down the middle of the tube.

I've done an experiment where I fill the cooler with water, and the start lifting the braid from the water by the end farthest from the outlet.  The flow rate remains unchanged.  This says to me that the braid length doesn't make all that much difference.  Is this an invalid test?
Title: Re: rice hull percentage
Post by: mrcceo on September 02, 2010, 04:32:58 PM
I'm not saying a short tube won't work, but the added length is a nice safety factor. Just stands to reason that the more surface area your filter has, the faster it will allow the runnings to flow and the less likely it will clog.

But why wouldn't the wort just flow in one side and out the other?  Why would it follow a perforated tube with so much open surface area?

Good point, but the majority of it will take the path of least resistance and that's down the middle of the tube.

I've done an experiment where I fill the cooler with water, and the start lifting the braid from the water by the end farthest from the outlet.  The flow rate remains unchanged.  This says to me that the braid length doesn't make all that much difference.  Is this an invalid test?

That test is not representative of the conditions when conducting a mash.  I would imagine you would have to conduct a series of tests with different length braids and different mashes which incorporated varying amounts of wheat and rye and then measure the volume/rate of flow from the valve in order to be conclusive.
Title: Re: rice hull percentage
Post by: redbeerman on September 02, 2010, 04:36:06 PM
You're right Denny.  It won't make a difference, all the fluid passes through the hole in the wall.  Gravity brings it to the bottom of the container.  A longer braid may help as far as clogging goes, though, as the grain has a larger surface area to compress.  With a short braid or for the sake of arguement just a screen in a fitting in the hole, if the grain is compressed against it, it has a better chance of becoming clogged.
Title: Re: rice hull percentage
Post by: bluesman on September 02, 2010, 04:45:45 PM
You're right Denny.  It won't make a difference, all the fluid passes through the hole in the wall.  Gravity brings it to the bottom of the container.  A longer braid may help as far as clogging goes, though, as the grain has a larger surface area to compress.  With a short braid or for the sake of arguement just a screen in a fitting in the hole, if the grain is compressed against it, it has a better chance of becoming clogged.

+1

The flow of wort will be most affected by the limiting factor which is the size or diameter of the hole from which it is flowing through in some cases.  In other words if you had a 30" braid and a 1/8" hole the flow would be restricted mostly by 1/8" hole. 

The question in my mind is "where is the bottleneck" in the system.  The grain bed...the braid...the outlet dia....or all of the above.

 The short answer is that they are all dependent upon each other to do their job but ultimately one will be a bottleneck per say.  One must look at the system from a fluid dynamics perspective and make the assessment.
Title: Re: rice hull percentage
Post by: mrcceo on September 02, 2010, 04:48:56 PM
You're right Denny.  It won't make a difference, all the fluid passes through the hole in the wall.  Gravity brings it to the bottom of the container.  A longer braid may help as far as clogging goes, though, as the grain has a larger surface area to compress.  With a short braid or for the sake of arguement just a screen in a fitting in the hole, if the grain is compressed against it, it has a better chance of becoming clogged.

That's exactly what were saying regarding the length of the braid.  A longer braid is less likely to clog because of the increased surface area therefore less likely to cause a stuck sparge.
Title: Re: rice hull percentage
Post by: tschmidlin on September 02, 2010, 05:03:26 PM
A longer braid is less likely to clog because of the increased surface area therefore less likely to cause a stuck sparge.

Yeah, in Denny's experiment the limiting factor is the outlet hole, the braid is no real impediment at all if there's just water in the mash tun.  For a mash though, bits of flour or wheat/oats from the grist can clog a braid depending on the hole size.  So you'd need to do the experiment with consistent grist and different length hoses to figure it out for sure, and then vary the grist with the hoses as well.

Hose length obviously does make a difference theoretically, but it might not make a difference in practical terms depending on your mash conditions.  It sounds like it makes no practical difference for Denny's typical mashes.
Title: Re: rice hull percentage
Post by: mrcceo on September 02, 2010, 05:19:26 PM
A longer braid is less likely to clog because of the increased surface area therefore less likely to cause a stuck sparge.

Yeah, in Denny's experiment the limiting factor is the outlet hole, the braid is no real impediment at all if there's just water in the mash tun.  For a mash though, bits of flour or wheat/oats from the grist can clog a braid depending on the hole size.  So you'd need to do the experiment with consistent grist and different length hoses to figure it out for sure, and then vary the grist with the hoses as well.

Hose length obviously does make a difference theoretically, but it might not make a difference in practical terms depending on your mash conditions.  It sounds like it makes no practical difference for Denny's typical mashes.

+1
Title: Re: rice hull percentage
Post by: denny on September 02, 2010, 05:23:54 PM
A longer braid is less likely to clog because of the increased surface area therefore less likely to cause a stuck sparge.

Yeah, in Denny's experiment the limiting factor is the outlet hole, the braid is no real impediment at all if there's just water in the mash tun.  For a mash though, bits of flour or wheat/oats from the grist can clog a braid depending on the hole size.  So you'd need to do the experiment with consistent grist and different length hoses to figure it out for sure, and then vary the grist with the hoses as well.

Hose length obviously does make a difference theoretically, but it might not make a difference in practical terms depending on your mash conditions.  It sounds like it makes no practical difference for Denny's typical mashes.

+1

Thanks for the discussion and your thoughts, guys.  When I was conducting my initial braid length tests years ago, it was in a real mash and that's where I found the braid length made no difference for me.  But as Tom points out, YMMV.
Title: Re: rice hull percentage
Post by: mrcceo on September 02, 2010, 06:45:55 PM
You're welcome Denny. 
Nothing like a little lively debate.
Title: Re: rice hull percentage
Post by: 1vertical on September 05, 2010, 09:46:51 PM
Ok,
My $.02...........I use enough hulls to cover the bottom of the cooler to the depth of the braid.  I wash the hulls with
the mash tun preheat water in the cooler because they are DIRTY for sure.  Uh sometimes I have slow runoff
even with this.  Braid is most of the length of the cooler (2/3) and 1/2 inch diameter.  My bulkhead may be the culprit.
Title: Re: rice hull percentage
Post by: Beertracker on September 06, 2010, 02:59:07 AM
I typically use a "couple" of handfuls when using wheat or rye malt in excess of 50%. Approx. < 2-3%?  :-\