kettle mashing

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Well-Known Member
Jan 3, 2005
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Clebland, OH
ok tell me what you guys who do the all grain think of this... this article and set up really fascinates me, mainly cause i don't have to spring for a cooler and piss around with transfering volumes of water at specific temps....i kinda like the one pot approach, but am concerned about yields... anyhoo, i like a spigot on my brew kettle anyway, so may modify just to use as a boiling pot....

We will begin the discussion, by describing the screening device and spigot that is installed in the brew kettle. The first one I made was made from galvanized pipe fittings and window screen, installed in a 32 qt enameled canning kettle.

The current version is all brass, copper and stainless installed on two stainless kettles, a ten gallon for mashing and fermenting and a sixteen gallon for boiling. Having two kettles allows one to be prepared for the next operation while the other is doing its thing.

Fig. 1 shows an exploded view of the spigot and strainer. The strainer is simply a 2 x 6 inch piece of screen, rolled into a six inch tube and clamped to the copper tube. The last half inch is bent over itself to seal it off. The copper tube has a slight bend in it to allow it to be rotated so that the end is right on the bottom leaving almost no wort behind. It is easily removed for cleaning.

The spigot passes through a clearance hole drilled in the kettle and is retained by the female connector and a washer to take up the treads and make a tight fit.

All the parts are available at a good hardware store. For those not inclined to hunt down the parts, a complete kit is available from the author.

Once the spigot/strainer device is installed in the brew kettle, you are ready for the plunge. If you are shopping for a kettle, my only advice is the bigger the better. I consider the 32 qt canner about the minimum for a 5 gal batch.

The following procedure is intended only as a starting point that I know works well enough to assure a successful, first, all-grain experience. I do not want to get into endless discussions about the pros and cons of the procedure at this time nor do I even claim that I brew beer this way. There are an infinite number of variations that could be fodder for future articles but the object of this one is to introduce the approach and brew a simple batch of all grain beer.

The first step is to dump 8 lbs of crushed pale malt into the kettle. Don't forget the screen! Add 3 gallons of warm tap water and mix thoroughly.

Apply heat and raise temp to 155F. Stir frequently to avoid caramelizing and to distribute the heat. Hold this temp for 30 minutes by adding heat and stirring as necessary.

After 30 mins at 155F, crank up the heat and continue stirring until 178F is reached. This step is known as "mashout" and is difficult or impossible to do with the plastic bucket approach. It is my opinion that it eliminates one source of a common problem with first all grain batches known as a "set mash.

Hold this temp for 10 minsutes, then turn off the heat and let it rest while heating water to a boil on another burner. Use a pan that holds at least two quarts of water.

The level of wort in the kettle should be about an inch above the grain when it settles. Lay a small bowl on top of the grain to distribute the sparging water and minimize the disturbance of the grain.

Open the spigot just a trickle and run the wort into a cup until it runs clear. Pour the turbid runoff back into the kettle. With this setup, it will run clear after a few ounces. Again, as comparison, it sometimes takes gallons with the other system and this must be recycled back into the mash till it does run clear.

The object of sparging is to extract as much sugar from the grain as possible. The longer it takes, the more efficient the extraction. Adjust the outflow so that it takes at lest 10 mins to fill a gallon jug. Pour the boiling water into the bowl as available or necessary to keep about an inch of water over the grain. The availability of boiling water will probably be the limiting factor on sparge rate.

Most brewers will tell you that the sparge water should not exceed 170F but if you use boiling water in this system, the average temp will be far below 170F and you will be lucky to keep it above 150F. You can fiddle on your next batch. Trust my on the first.

The first runoff should be about 1.080 and you quit when it gets below 1.010. The total blend will produce 6 to 7 gallons at about 1.035 which, after boiling will yield 5 to 6 gals at 1.040. Collect the wort in gallon jugs or five gallon plastic buckets (can't get away from them).

I'd highly recommend putting a faucet on your kettle, especially if you go to 10 gallon batches.

I would also recommend going with the cooler and infusion mash method (adding hot water). It's really much easier than what this article describes. You just add water once, and it's always the same temperature (unless you're doing something fancy). I heat mash water to 171 degrees every time. Adding that to grain results in a tem that's 150 or so. I stir once and walk away for an hour. Simple as that. And actually I use a modified keg as a mash tun and wrap a blanket around it, instead of using a cooler.

Applying heat directly to the mash is never a good thing and will lower yields. It sounds like the guys in this article mess around with their mash much more than I do. You really want to not disturb it at all. Plus, you still need a big kettle, thus 2 pots, so I don't see what it gains you.

It also doesn't mention how they heat their sparge water. so, you still need another kettle to do that. I just don't think it gets much simpler than the 3-tier, 3 kettle system, and it works great. These guys would still need 3 kettles as far as I can tell, so the only difference is they apply heat to the mash instead of adding hot water, which is both more difficult and produces worse results.
twenty questions time all :)

how can you tell your mash extract yield level?

does the thermos really keep the mash at a constant temp? i can get a ten gallon one for twenty bucks

can i make a drain/filter set up similar to the one described above in the thermos? maybe even with pvc piping and filter element.

i am done with extract as the primary basis of the wort, it's too damned expensive, i looked at my last bill and i spent as much on 3 lbs of extract as i could of on ten pound of grain....

i have some questions about liquid yeast starters too... but i'll dig up another thread...
It sounds like his method is just as complicated (or more) as using a traditional mash tun... he states "After sparging in the lauter tun, the kettle is used for boiling". This sounds like he's using the kettle for a mash tun, moving the grain to a seperate lauter tun, cleaning the kettle, sparging, and boiling..... That's WAY too much work. You can use a piece of copper pipe in the bottom of a cooler, or even install a premade Bazooka screen as a mash / lauter tun easily.

I can see using your kettle as a HLT... but using it as a mash tun just sounds (you'll pardon the expression) as messed up as a football bat.
no he uses the kettle for a lauter tun as well... the grain bed acts as a natural filter element, course he stops up the bung hole with some wire mesh as well.... it's a real slow bleed off of the liquid.

i am stubborn enough to try this out and it sounds a bit like how the old timers used to make beer. it's basically what i'm doing atm sans the spigot on my kettle....

another question, i'll just keep this as my generic equipment thread ;)

a large drink cooler? or an insulated picnic cooler? which do you prefer and how do you get yer sparge water on the grain, more hoses and tubes and valves?

i saw a very interesting setup this afternoon,an insulated picnic cooler with a drain/filter setup inside, she said it gave the advantage of spreding the grain bed out over a greater distance and helped avoid the stuck runoff you can get with the vertical drink/water cooler... if i go the plastic route i think i'll go with the picnic cooler, mainly cause i have a four or so laying around the garage...
I'd really recommend rethinking your sounds like a LOT more work to myself and to Uncle Fat. Frankly, I can't see any benefit to trying to use a single kettle for all three purposes, nor do I see what it gains you. I don't think it's any more like the "old timey" way, either...after all you're talking about using a plastic cooler. And if you're extract brewing, then this method is still *nothing* like what you're doing now. It isn't as simple as a spigot. All-grain is a very different beast.

Just don't want you to build a setup you won't be happy with...there are lots of disadvantages to this system (applying direct heat, juggling one container when you should have 3, etc, etc)

Some things to think about:

How can he possibly use the kettle as the mash/lauter tun? The liquid flowing out the bottom needs to go somewhere...normally it goes to the kettle.

How could you use your kettle as a HLT? When sparging, all three vessels are in use at the same time. The HLT is slowly sprinkling sparge water on the grain bed which is slowly draining into the kettle. I don't see a way around that, nor do I see any advantage in bending over backwards to avoid a traditional 3-vessel setup.

But, hey, that's just me. ;) Oh, and Uncle Fat, too :D
Oh, sorry...yes, the cooler holds temperatures very effectively. That's why nearly everyone starts out with a cooler for a mash tun. Be careful what shortcuts you choose to take. Cheers! :D
the kettle mash as described in the article (i only cited 1/3 of it in quotes) is pretty straight forward, and the author claims to use the kettle to mash the grains, then sparge with water heated in another kettle, using the grains as a filter element. the liquor goes out the spigot into another kettle. the article describes having two or three large kettles, to boil water and collect sparge runoff.... so it's similar to having a three vessel setup, but one vessel you can apply direct heat to, which janx and others have cautioned is a no no cause you can burn the grains etc....

i think you guys are confusing the plastic with the kettle, perhaps it's my poor communication skills. i am saying i already have the kettles, i may just modify one and see how it works, and at the worst, i'll have a kettle with a spigot.... ;)

you obviosly need two or three large kettles to do all grain, even if you're using a cooler....

right now i have been doing the mini mash as described in the complete joy book and several other articles i've read. i end up with about four gallons of the liquor from the mash, to which i've been adding three pounds dme (trying to get away from that cause of cost) then commencing the boil... i top it off in the fermentor with water to equal my five gallons....

which brought me to my next question, picnic cooler or drink cooler, cause i agree that the kettle mash is prolly more work than required.

thanks for the replies :)

edited so's not to appear snooty or ungrateful ;)
t1master said:
i am saying i already have the kettles, i may just modify one and see how it works, and at the worst, i'll have a kettle with a spigot.... ;)

you obviosly need two or three large kettles to do all grain, even if you're using a cooler....

Ok, just so I understand you... You're pretty much talking about a traditional setup, with an HLT, mash / lauter tun, and boil pot. But you want to use one of your metal pots as a mash tun instead of having to buy a cooler (is that about right?).

If that's the case... You'll do just fine. The only trouble I can forsee is that the metal is always a better heat conductor than plastic, so you may need to either do recirc mash, or insulate the mash kettle to keep the temp close to constant. This kind of setup is really not uncommon at all. Look at systems by Brew-Tree and MoreBeer. Their high-end systems all use a converted kettle for mashing. As far as how to sparge... My tun is designed pretty similar to this one: BrewTree Economy Tun . You can just use a coiled bit of soft copper, with some holes drilled in the bottom for sparging. You keep speed constant with the valve on your HLT.

When you go to all grain, I suggest using a faucet (spigot) on ALL your vessels. You'll have to boil about 7 gallons of wort to get 5 gallons of beer. You don't want to be trying to tilt a kettle with 56 lbs of boiling wort to transfer from one vessel to another. In my system, the only (slightly) heavy things I lift are the mash tun full of spent grains, and the fermenters when I'm done.

You should also think about putting a screen / false bottom / drain manifold on both your tun AND your brewpot. One to keep the grains in the tun... the other to keep the hops in the kettle.
that's about it mate! sorry if i sounded confused before, still learning as i go, and i lean towards the daft side at times ;)

so i guess the cons outweigh any benefits of mashing in metal on a large scale. it seems to work for about five pounds of grain, but anymore and i could forsee numerous problems. and everyone so far has pointed me towards a plastic, insulated vessel to mash in. so i will modify a cooler methinks.
t1master said:
that's about it mate! sorry if i sounded confused before, still learning as i go, and i lean towards the daft side at times ;)

Doh! Woah! I was sooo confused. I guess I only read the segment of the article you posted, and for some reason I thought you were trying to use one kettle to do all and I just couldn't see it. My bad! Did I say "Doh!" ;)

The setup you're describing sounds just like mine. I use 3 converted stainless kegs. I actually very much *prefer* a mash tun made of stainless to a cooler because the rate I brew tends to destry coolres. Eventually the heat warps them and the layers separate etc.

So, I have 15 gallons of capacity in each vessel and brew batches that end up at around 12 gallons. We just wrap a blanket around the mash tun and it holds heat just fine. Believe me, all the conversion is done in about 15 minutes anyway. I used to have a keg that had a sheet metal jacket insulated with about 3 inches of rigid foam insulation, but the thing was such a huge beast that this time I decided to just go with a blanket. Works great, even if it isn't as high tech ;)

Another thing about the bigger mash is it tends to hold its own heat better just because of thermal mass.

I had a RIMS system before this one and it could hold temp within a couple tenths of a degree perfectly. But when I buyilt my current system, I went back to basics with the three tier infusion setup. I like the low-tech method so much more, and the fact is, if you get your mash temp pretty good, conversion always happens and works great.

As Uncle Fat said, put a spigot on every vessel and build a 10 gallon system. I also like a minifold made of a pipe of some sort with drilled holes over a false bottom, but that's just me. A filter on the outflow of your kettle is a must, as Uncle point out, for the hops. Getting hops in your chiller can really suck.

So, sorry about the confusion. I feel like a dumb a** for not thoroughly understanding where you were coming from. Stainless mash tuns are great...better than coolers as far as I can tell.

If you do get a cooler, I like the big orange Gott coolers. They make a 1o gallon one that can do a pretty big batch.

Cheers! :D
Is there a thread where you describe your mash/lauter to boil kettle process in detail? I see so many people handle this process in so many different ways. Just curious how you go about the process.

You mention that a blanket works just fine for holding temps. And this works well? How important is hold temp really? The book I read said to hold between 150 and 155 for an hour.
Hey uglygoat, I've been a lurker on these boards for some time, but your question finally got me to register and post! I've been toying around with the idea of mashing in my large kettle.

I'll probably get heat for this, but here's my take on things:

  • As stated, the main advantage of using a cooler is heat retention and temperature stability. It's also a relatively simple and easy to learn setup. Best of all, it allows you to "Set it and forget it" and walk away for an hour (assuming you do a single infusion, meaning mashing only at one temperature).
  • The main disadvantage to that is that if, for whatever reason, you want to do a multi-rest mash at 2 or 3 different temperatures, it's a challenge because you can't just turn on the burner and heat it. When you read a recipe that tells you to go to 170 degrees for 10 minutes for "mash out", that's what it means. Most people who use the cooler method just skip the mash out and have their sparge water at that temperature.
  • One method of increasing the temperature in a cooler is to limit the water in the earlier stages of the mash and to keep adding new infusions of hotter water. This works, but it's a bit of a fudge because sometimes you need to have a really thick mash in the early stages, which isn't always optimal. But it works.
  • The reason so many home brewers do simpler, single-infusion mashes is because it's so much easier, but the reason that they CAN is that these days most malt his well-modified, which means that you don't need to do that lower-temperature rests (acid rest, protein rest…) to release all the proper enzymes in stages. Even with a single infusion you can get to good extraction efficiency. You would get an even higher efficiency if you followed the old process, but these days most people agree, it's not worth the effort.
  • One counterargument to the design you linked to is that to really do it right you would need to either significantly insulate the kettle, which would be dangerous on an open flame, or to have a rig that runs though another pot of hot water that is essentially the opposite of a wort chiller, but it woudl require a pump, which adds to the cost an complexity.

I use a cooler. In case you're wondering why I am toying with the mash kettle approach is that I'm curious about what the impact of the simpler approach is on flavor. Everyone always focuses on the mash efficiency and gravity. However, the multiple rest stages at different temperatures have other impacts on taste and body. I'm curious as to the difference. For example, my next brew is going to be a Fat Tire clone. I decided to try the Northern Brewer recipe, which everyone agrees produces a good beer but one that isn't, in fact, all that much like Fat Tire. The recipe calls for a multi-step mash option, an my curiosity has gotten ahold of me as to whether that makes a difference, since I am sure most people have mashed it using the single infusion options. As a result of this curiosity (but also not wanting to buy new gear blindly), I am going to go down the rabbit hole of decoction mashing. My 5 Gal. MLT cannot hold the 6+ gallons of water that would be required. So I am clearing my schedule, starting early one day, and giving decoction a shot. I think the maillard reaction will also help with the Fat Tire flavor. If it works, I will consider shifting to a mash kettle setup in the future.
I know I'm late- but I have to put my 2 cents in here. I saw a few people talking about a direct-fired tun like it was a no-no. A direct fired mash tun is a beautiful thing if you like or need to do a lot of step mashing. Without it, you're either going to have to decoct, or do several infusions of boiling water. Both of those options are a pain in the a** and difficult to control.
"Why would I need to step mash?" If you have a grist with a high percentage of Pilsner malt, wheat, oats, etc (adjuncts, unmalted grains and the such) you need to step mash. I've seen people who stand firm by the single infusion method- and that's great- but there is a lot to be said for step mashing. It yields great results (if you pay attention) and is (to me anyway) a lot more fun than just dumping water into a cooler and walking away for an hour or so. After all, we hombrew for fun-right? If all we wanted was good beer we could go to the bottle shop.