Partial Muslin Mash Questions

[fendersrule]

I want to post about this because this is my favorite way to mash if I'm not doing an all-grain brew day. I have some open questions because I really would like to perfect this process.

With a Partial Muslin Mash, you are essentially brewing in a bag, but you are also partial by adding DME in the end. Actually, I would say that this is nearly exactly the same as B.I.A.B--you use the kettle for everything. This is ideal for those that are leaving extract brewing, but don't want to buy additional equipment. Muslin socks are dirt cheap and dispensable. For 12lbs of grain, I usually use about 4 socks.

1) Crushing. This is where I'm curious how fine you can crush for Muslin socks. By belief is that you can probably get by with a finer grind that what I usually do. I essentially crush grain to where I would if I wanted to leave a grain bed. That means grinding to at least cracked husks, with only very little powder. Of course many husks get broken, but you get the point, it's not a fine grind like you'd do for B.I.A.B. Question: I believe you can get much higher efficiency with a finer grind. Does anyone have a grounding spec for how fine you can go if grains are placed in Muslin socks?

2) Bags. "Large" muslin socks is only what I've used because they are so easily available: I haven't actually tested this, but I believe that 5lbs is too much to place in large muslin socks. It will "fit", but I suspect grains in the center may not even get wet, leading to poorer efficiency. I would suspect that somewhere around 3lbs should be a "safe" max to put inside of a muslin sock to assure that the center gets wet and to allow for proper drainage. That means for 12lbs of grain, you really should plan on 4 large socks. That's $2, cheap. You can also step up and get something more like a B.I.A.B. "bag" and just fill it all the way up, or use a strainer bag at your local hardware store.

3) Mashing water. Question: Many people say 1-2 quarts/lb, but I want to question this for this method. Because this method is identical to B.I.A.B. (much less grain though), I would think that you COULD mash near to pre-boil volume, minus a gallon or two for splarging would lead to greater efficiency. Or, is there a thing with having too much water for mashing?

4) Splarging setup. I choose to fly splarge here. When mashing is done, I pull the bags out, and place them on an oven rack that sits on top of the kettle and let the bags drain for a few minutes. I've splarged with cool water and I've splarged with hot water (170F). My experience matches the one-guys study that hot water grains you a few points extra of efficiency (OG), so I prefer to use hot water. I slowly trickle down 170F water on the bags, flipping them, squeezing them, repeating the process, until all the fluid that drains is clear. This usually takes about a gallon or so of splarging, and I've never seen the need to do this over 10-15 minutes. I've noticed when using cold water that I lose color pretty quickly from the drain, so cold water doesn't do the best on rinsing grain.

 

[IslandLizard]

On 2):
As long as you don't get a ton of grain particles and dust in your wort, whatever bag you use is fine. Yes, the crush can make a difference on what bag works best.

Hydrating (thoroughly wetting) the grain is very important as starch conversion takes (mostly) place in the liquid medium. Just letting it hang and soak is indeed no good. Dunking the large sock up and down especially in the beginning and a few times every 3-5 minutes during the mash period should get you there. Just don't use a large kettle full of water, perhaps mash in a smaller, better sized pot, placed in a prewarmed but turned-off oven, so it stays at the right temps.

On 3):
A relatively large volume of strike/mash water will dilute the enzymes a lot, they get dispersed into your water where there are no gelatinized grains, they're in the bag. So I'd say stick to 1-2 quarts a pound, perhaps a little more, but don't go overboard.

After the hour mash, sparge the (smallish) 'partial mash' bag with grains once or twice in a separate pot/vessel/bucket, and add the collected 'runnings' to your kettle. Add enough water to get to your pre-boil volume as you bring it to a boil. Dissolve your extract (or part of it) and brew away.
Or do pour overs as you do in 4), either is fine, one may give you a few extra points over the other depending on methods used.

At the end of the boil add any withheld extract, and chill.

On 4):
The word is 'sparge' or 'sparging.'

What you're doing is definitely NOT fly sparging. You're merely pouring (hot) water over your grain bag and squeeze! But it is fine, many BIAB brewers do it that way.

 

[fendersrule]

Thanks. I called it fly sparging because there's near continuous water going in, and continuous water going out. It more closely resembles that vs batch or dunking...

Thanks for the explanation that sticking to 1-2 quarts per lb is still the right thing to do.

I'm still curious on how fine you can grind the grain for muslin socks. .0036"? .0040"? Trying to remove as much trial and error so that next time, I can count on better efficiency.

Good point about the muslin bags and making sure it's "mixed" into the water as much as possible. I drop them in, smash them carefully with the backside of my brewing spoon, and stir for about a couple minutes (while flipping them) and "smash" them again. After that though (about 5 minutes) I leave them alone and let the mashing do it's thing. Because the grains are fairly well suspended off the kettle, I will come back after 30 minutes and reheat back up to my mash temp. The main reason I do this is because this allows me to stir and smash some more. Using this Muslin Partial Mash method, you can actually do this without risk of burning or any other issues. With the B.I.A.B method, you have to just let it sit and you cannot re-heat because the grains are not as suspended. If that makes sense...

Here's an image of a typical grind that I do for the muslin sock method. I believe I could go finer.

 

[IslandLizard]

Those are gap settings for roller mills? I don't think you have settings on a corn mill like that. If they do, they may result in different results.

Eyeball it.
As long as there are no whole kernels left, you're crushing. Now how fine you can go with that crush is trial and error, you van optimize for your system. You're using a hybrid BIAB, so finer may work well.
My milled grist (2-roller mill) does not have many particles that are larger than 3/32" from the looks of it. I have a conventional cooler mash tun, and do 2 batch sparges with half the sparge volume each. ~85% mash efficiency. My 3rd (and last) running are around 1.020 (+/- 5 points) that way, depending on the recipe's gravity.

Your muslin sock stretches, enlarging or rather elongating the openings somewhat, but at the same time it constricts (squeezes) the content tighter, preventing much to get out.
If you think you can do better, crush a little finer next time. Or buy a piece of voile curtain material in the Walmart of fabric store, and make your own BIAB bag. Voile is quite a bit finer mesh than stretched muslin.

BTW, nothing wrong with using a corn mill!

 

[IslandLizard]

In my early brew days I used to do steeping and later mini mashes in a 2 gallon pot (in the oven). Sometimes a smaller 2nd or 3rd pot. Strain/lauter through a mesh sieve into another pot or small bucket where the sieve could sit on the rim.

Agreed, direct heating a kettle with a bag that touches the bottom is asking for trouble.
I sometimes step mash in my kettle, do a mashout then using the mash tun for lautering and sparging. It's very difficult to heat a plastic mash tun or its content by just adding boiling water!

 

[fendersrule]

I ordered a cereal killer yesterday because I'm moving to BIAB, and since I'm going to be churning so much grain, the cereal killer should produce much neater results with less dust and stuff....straight into the bucket....and arguably more consistent results. Yes, nothing wrong with a Corona mill!

The gap settings I'm wondering if I wanted to try this muslin method again would be for the ceareal killer, not the corn mill. Probably will never use the corn mill again.

Thanks for the info! "eyeballing" sounds about right...make sure all kernals are crushed, not just "split".

My previous beer instructor (who wasn't very good at making beer) told me that most kernals should just be split. I've never really questioned it as I started to evolve into better brewing processes. Glad I asked, because now I think is the time to crush more.

If I'm going through the process of cruising more, might as well just get a finer mesh bag, one that I can reuse, and one that would be good for ~12 lbs of grain. Good idea.

 

[fendersrule]

I wanted to state the reason I ask this about my Partial Mash Process is because I'm fairly sure I will still utilize this process in the future, even if a lot of my brew days will be all grain B-I-A-B method. Partial Mashing still has its place....making small experimental batches, etc.

 

[IslandLizard]

I crush at 0.034" for Barley and reset the mill to 0.028" for Wheat, Rye, and flaked goods (yes, I crush those too!).
With your new CK, using BIAB you can probably crush everything at 0.025" (or even finer) and never look back.

 

[fendersrule]

Cool, thanks. Since I'm in no hurry, aside from making one from voile, is it common to fine "grain bags" (not necessarily BIAB type bags that surround the inside of the kettle) but just really fine nylon bags that you could poke 12lbs of grain into....would probably expect it to have a draw string or something to contain the innards, and is reusable?

It seems like that would have benefits over a muslin sock for the PM method in that a) reusable, b) allow for fine grinding (.025"), and c) won't "compress" the grains...

Edit: probably something like this!

https://www.morebeer.com/products/drawstring-mesh-bag-24.html

a 24" x 24" bag seems large enough...too large for 12lbs of grain?

https://www.morebeer.com/products/drawstring-mesh-bag-15.html

Maybe 2 15 x 15 will be better.

 

[IslandLizard]

I wanted to state the reason I ask this about my Partial Mash Process is because I'm fairly sure I will still utilize this process in the future, even if a lot of my brew days will be all grain B-I-A-B method. Partial Mashing still has its place....making small experimental batches, etc.

Or just do full size mashes for everything...

When you do small test/experimental batches, using a smaller cooler (or pot) with a bag for mashing makes life a lot easier. A smaller boil kettle is more manageable too.
Or mash a large batch and boil/finish smaller parts of it, say, using different hops or for using different yeasts.

I only use DME for starters now.

 

[fendersrule]

Exactly! If I get obtain a good array of large nylon bags, and if I wanted to make 1 gallon experimental batches, I could easily do that from all grain---and still use my lay-bag-over-kettle and hot-water it method for sparging!

No DME!

 

[RM-MN]

My opinion only, not much info to back it up:

1. Crush is the key to mash efficiency. The finer the crush, the faster and more complete conversion. If the grain doesn't get wet all the way to the center, the starches there don't get converted to sugar. There doesn't seem to be much limit on how fine you can go. If you get the crush really fine you may get more grain particles in the fermenter. I haven't been able to get too much so that if affects the quality of the beer.

2 Paint strainer bags are readily available and reusable too. I tore my first after only about 3 years of hard use but the second one is still going at somewhere around 5 years. My thoughts on the difference in using them instead of the muslin socks is that the paint strainer bags don't constrain the grains so the water flows freely between all the grain particles.

3. Mashing water to grain ratio doesn't seem to affect the mash efficiency. I've gone all the way to 4 quarts per pound and efficiency was still good. What does matter is that the grains can't buffer out the alkalinity of the water in such a high ratio so acidifying may be necessary to keep the pH in the proper range.

4. When you got more sugars out of the grains by sparging with hot water it was because not all conversion was complete before you sparged, probably because the muslin bags kept the water from reaching all the grain during the mash.

5. You may find that the Cereal Killer mill is faster than the corn/grain mill you have but there certainly isn't anything wrong with using either. Keep good notes on the mash efficiency for both mills and the setting you use. I have the corn/grain mill and get very high efficiency with it. I doubt you can exceed that with your Cereal Killer. I control the dust by slipping a plastic bag over the end of the grain mill. A one gallon bag will hold all that will fit into the hopper of the mill and is easy to dump into the kettle with one hand while stirring with the other.

6. If you mill the grains fine, you don't have to worry about burning the bag when reheating because you won't lose head during the conversion as it happens extremely quickly. Once the starches are converted to sugar the temperature doesn't matter much as the rest of the time you are simply extracting the flavors and colors, much like you would for making tea.

7. It is quite easy to motorize the cheap corn/grain mill. I have used my electric drill for that. I can mill the grains much faster than I can heat the water to strike temp so I have never seen the need to get a roller mill. In fact, I usually mill the grain next to where I heat the water and do it by hand most of the time so I am right there monitoring the temperature of the water. When I motorize the mill, I'm finished way before the water is at strike temp and have to just stand there watching the water heat up.

My previous beer instructor (who wasn't very good at making beer) told me that most kernals should just be split. I've never really questioned it as I started to evolve into better brewing processes. Glad I asked, because now I think is the time to crush more.

With a conventional mash tun, making the grain kernels too small invites a stuck mash or sparge. Leaving them larger avoids this but really cuts down on the mash efficiency. Using a bag to contain the grains eliminates the stuck mash because the bag forms the filter instead of the grains doing it and the bag can be raised to increase the filter area.

 

[BrewnWKopperKat]

With a Partial [...] Mash, you are essentially brewing in a bag, but you are also partial by adding DME in the end. Actually, I would say that this is nearly exactly the same as B.I.A.B--you use the kettle for everything. This is ideal for those that are leaving extract brewing, but don't want to buy additional equipment.

Partial mashing is often (perhaps too often) viewed as an intermediate step from extract+steep to "all-grain". For me, it is another technique/process for brewing. As a hobby, isn't it about brewing a good beer with good ingredients (including fresh DME ) in the time that's available?

A couple of resources that I have found helpful for partial mashing are the book "Methods of Modern Homebrewing" and beerandwinejournal.com (Chris Colby). Older episodes of "Basic Brewing Radio" also talk about partial mashing.