Author Topic: Aluminum or Stainless Steel?  (Read 5464 times)

Offline hopfenundmalz

  • Official Poobah of No Life.
  • *
  • Posts: 4535
  • Milford, MI
    • View Profile
Re: Aluminum or Stainless Steel?
« Reply #15 on: June 03, 2010, 05:38:54 AM »
I am seeing some very good deals for SS stockpots that make them competitive with stainless (at least for basic pots without ball valves, etc.). Where I hesitate is the weight of SS versus aluminum and the impact on hoisting it/heating it/cooling it. I have a 4-gallon SS pot and am trying to envision the weight of this pot at 7.5/8/9/10 gallons and the extra effort to bring it to a boil and cool it down. Thoughts?

AL is fine.  SS will be heavier.  The conductivity of SS is lower than AL.  The difference in time for heating and cooling is negligible.   If it was really longer, professional chefs would have issues.

Since I am an engineer (but I must say that I am not a heat transfer engineer and that class was a long time ago) here is why.  The heat transfer will depend on the conductivity of the metal and the liquid.  Wort is mostly water so I will use that.
Aluminum = 250 (W/mK)   Stainless Steel = 16 (W/mK)   Water = 0.58 (W/mK)  A bigger number means that there is more heat conductivity.

The liquid controls the heat transfer due to its much lower conductivity.  That is why you stir your pot to heat or cool it faster. 
Jeff Rankert
Ann Arbor Brewers Guild, AHA Member, BJCP Certified
Home-brewing, not just a hobby, it is a lifestyle!

Offline bonjour

  • Administrator
  • Senior Brewmaster
  • *****
  • Posts: 1771
  • Troy, MI, 37mi, 60.9deg AR
    • View Profile
Re: Aluminum or Stainless Steel?
« Reply #16 on: June 03, 2010, 07:27:58 AM »
Functionally I see little difference between them,  The Al MUST be seasoned prior to wort going in, and that may mean re-seasoning after a cleaning (depending on how vigorous),  SS is non-reactive and thus more forgiving.  But properly handled they both work fine.
Fred Bonjour
Co-Chair Mashing in Michigan 2014 AHA Conference in Grand Rapids, Michigan
AHA Governing Committee; AHA Conference, Club Support & Web Subcommittees



Everything under 1.100 is a 'session' beer ;)

Offline richardt

  • Senior Brewmaster
  • ******
  • Posts: 1227
    • View Profile
Re: Aluminum or Stainless Steel?
« Reply #17 on: June 03, 2010, 07:34:02 AM »
KGS,
I have used both aluminum and stainless steel.  I prefer the later which does have an aluminum disc at the base (tri-clad SS kettles).  I prefer SS’s aesthetics and cooler handles (to the touch).  Aluminum conducts heat so well, in fact, that I have stupidly burned my hands on the handles during my lapses in attention.   I now have oven mitts and or leather gloves in my brew gear to prevent this—I use the leather gloves when working with the hot kettle and liquids as it also has saved me from burning my hands on hot wort chillers or spigots or splashes.  It also gives me more confidence with my grip.  I realize that it makes me look like a wide receiver, but I don’t care.  I hate burns and my hands are important in my work.
http://www.instawares.com/nsf-stainless-steel-stock.rii-royssrspt80.0.7.htm
Royal NSF SS stock pot with lid, 80 quarts (20 gallons) = $181.69 (ships free).
http://www.amazon.com/Pro-Quality-Titanium-Step-Drill/dp/B000RP82F8/ref=sr_1_12?ie=UTF8&s=hi&qid=1275570805&sr=1-12
Pro Quality Titanium Step Drill Bit 7/16” – 1-1/8” by 1/16” increments = $6.25 + $4.75 S/H ($11 total)
[If you want to make a spigot for your SS Kettle, you’ll need a 7/8” hole in your SS kettle located about 1.5 inches up from the bottom (on center).  You will need this extra room for the washer that goes on the inside of the kettle with the weldless SS valve.  This drill bit and your 3V corded drill at home will do this perfectly—just wear safety glasses when you do it.  I put the spigot directly below one of the handles on the SS kettle since I wanted to be able to carry the kettle w/o fear of knocking the spigot and to have the ability to lift the kettle with just the opposite handle  (i.e., tilt the kettle) to encourage drainage].  To finish off the hole, I used the drill bit from both ends (i.e., outside the kettle and inside the kettle)—taking care to keep the bit perpendicular to the hole/kettle wall—in order to de-burr the edges of the hole.  There was no need to use 3-in-1 machine oil (though some recommend it) or a metal file.  My dremel was worthless for deburring—use the drill bit with light pressure from both sides of the kettle—it makes a perfect, symmetrical, and clean hole.  Just take your sweet time and do it right.  Periodically test the size of the bulkhead fitting through the hole; you want it to be a snug fit.  The hardest part for me was the overcoming the mental aspect of drilling a hole in such a beautiful kettle!
http://cgi.ebay.com/Weldless-Stainless-Steel-Valve-and-Spigot-Free-Shipping-/380122770975?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item5881152e1f
Weldless SS valve and spigot = $47.50 (ships free)
Total cost:  $240.19
I personally use the cheap metal or digital thermometers that run around $10 and don’t have much use for a sight glass since I boil at ground level and look into the top.  I have my spouse or a brew buddy help me lift the kettle to a higher location (e.g., table top or tailgate) after chilling to facilitate gravity transfers.
If you want to have the beautiful Blichman Boilermaker 20 gallon brewpot (spigot, thermometer, sightglass), then it will cost you about $400.  If you do it yourself, you save about $150.
http://www.rebelbrewer.com/shoppingcart/products/Boilermaker-Brew-Pot-%252d-20-Gallon.htm
The big thing for you will be weight.  Aluminum pots are lighter than SS (a 20 gallon Aluminum pot is 16.5 lbs, while a SS pot is 36 lbs).  I like the 20 gallon kettles because it allows for easy brewing w/o boilovers of 10 gallons batches of any targeted SG you desire.  You’ll only be limited by how much grain you can stuff in your 10 gallon Igloo/Gott cooler or the larger rectangular coolers.
One US gallon of water weighs 8.35 lbs.  So lifting a 20 gallon SS kettle (36 lbs w lid) with 10 gallons of 1.050 SG wort (8.35 lbs x 10 gallons x 1.050 SG = 87.7 lbs) would mean lifting 123.7 lbs.
 Lifting a 20 gallon kettle with 15 gallons of wort (e.g., at pre-boil) means lifting 167.5 lbs (36 + 131.5 = 167.5).  Given the weight and bulk—any lifting or transfers should be a two person job (with the lid on).  I’ve done it alone once, but it wasn’t pretty and I won’t do it again.  There’s no way to lift it alone w/o having to prop the hot kettle against some part of your body during the lifting process.

Offline hopfenundmalz

  • Official Poobah of No Life.
  • *
  • Posts: 4535
  • Milford, MI
    • View Profile
Re: Aluminum or Stainless Steel?
« Reply #18 on: June 03, 2010, 08:15:18 AM »
On the weight thing.  Invest in a March Pump, no heavy lilfting. 

With no pump, I would not brew as much.
Jeff Rankert
Ann Arbor Brewers Guild, AHA Member, BJCP Certified
Home-brewing, not just a hobby, it is a lifestyle!

Offline kgs

  • Brewmaster
  • *****
  • Posts: 754
  • San Francisco, CA
    • View Profile
Re: Aluminum or Stainless Steel?
« Reply #19 on: June 05, 2010, 04:55:45 PM »
Thanks on the responses. I went to a restaurant supply store today and looked at/lifted various pots. The interesting thing was that SS wasn't always the heaviest, aluminum wasn't always the lightest, and for any particular line of stockpot, the weight difference between 32 and 40 was negligible. It is how much I put into the kettle that will make a difference. That's where I think that beyond half batches, I will have to go to a pump system.

But in looking at the surface area of 32 to 40 quart pots, I can brew 3-gallon batches (starting with 4 or 4.5 gallons) without detriment, so the pump could be another step, later. I might want to keep an eye on the rigor of the boil, but these pots aren't a quantum leap from what I have.

Also, I agree, the hardest part about the drill bit is preparing myself to drill into a new kettle.

K.G. Schneider
AHA Member

Offline euge

  • Official Poobah of No Life.
  • *
  • Posts: 7225
  • Estilo Casero
    • View Profile
Re: Aluminum or Stainless Steel?
« Reply #20 on: June 09, 2010, 11:15:41 AM »


Also, I agree, the hardest part about the drill bit is preparing myself to drill into a new kettle.



I am preparing to do such a thing. Had my March for about two months now and slowly working up the gumption to drill on my kettles. Almost out of beer and I need to brew. But its so darn hot already...
The first principle is that you must not fool yourself, and you are the easiest person to fool. -Richard P. Feynman

Offline rkausch

  • 1st Kit
  • *
  • Posts: 18
    • View Profile
Re: Aluminum or Stainless Steel?
« Reply #21 on: June 23, 2010, 11:28:24 AM »
Quote
Also, I agree, the hardest part about the drill bit is preparing myself to drill into a new kettle.

If you have a friend who is into woodworking, and has a full sized drill press (the kind that go on the floor, and are about 6ish feet tall), with an adjustable platform, give them some beer, and have them help you with the drilling operation.  I did this with my father's drill press on my new 25 gallon MegaPot, and had the same reservations. 

The drill press is a delta, and the table can lower down to about 1.5 feet above the base.  We clamped two pieces of wood on either side of the table, to act as a cradle for the kettle, and set the kettle on its side to drill.  Used a step-bit in the drill press, and went to town. It worked perfectly, and the drill press helped to keep the kettle from moving around while drilling. 

My only other advice is to wear gloves.  I'm used to wood working, and after a cut or drill, just brushing aside the sawdust with my hand.  I do it subconsciously, and tried to do the same with the metal shavings.  Those things are SHARP!  I cut my hand up pretty good (though I always cite superstition that if no blood is spilled while building something, the project is doomed to failure).

Offline hokerer

  • I spend way too much time on the AHA forum
  • ********
  • Posts: 2634
  • Manassas, VA
    • View Profile
Re: Aluminum or Stainless Steel?
« Reply #22 on: June 23, 2010, 12:19:17 PM »
My only other advice is to wear gloves.  I'm used to wood working, and after a cut or drill, just brushing aside the sawdust with my hand.  I do it subconsciously, and tried to do the same with the metal shavings.  Those things are SHARP!

Been there, done that!  It's almost impossible to NOT subconsciously swipe - ouch.
Joe

Offline richardt

  • Senior Brewmaster
  • ******
  • Posts: 1227
    • View Profile
Re: Aluminum or Stainless Steel?
« Reply #23 on: June 23, 2010, 01:54:16 PM »
I did my drilling with a cheapo old corded drill and a new step drill bit.  I took my sweet time.  It was suprisingly easy to do.
Agree with the metal burrs and shavings being a bit sharp. 
But, if you gently brush it off with a brush or vacuum attachment--you won't cut yourself.
The shavings tend to fly off the drill--when the metal bits hit your skin it kind of feels like a 4th of July sparkler being held a little too close to your body.  Nothing too serious, but it does get your attention.
So, before you drill wear Safety Glasses (no matter what), gloves, and long shirt/pants if you're really timid or into protection.

Offline BrewArk

  • Brewer
  • ****
  • Posts: 452
  • Rick - Newark, California
    • View Profile
    • BrewArk
Re: Aluminum or Stainless Steel?
« Reply #24 on: June 24, 2010, 09:56:04 AM »
...
So, before you drill wear Safety Glasses (no matter what), gloves, and long shirt/pants if you're really timid or into protection.

& ear plugs!
Beer...Now there's a temporary solution!

Na Zdraví

Offline silentknyght

  • 1st Kit
  • *
  • Posts: 4
    • View Profile
Re: Aluminum or Stainless Steel?
« Reply #25 on: July 20, 2010, 10:45:16 AM »

When you boil it all down, though, it seems that Aluminum is fine, you just need to be aware of a couple of things.  Before you brew in aluminum, you want to "passivate" it.  Just fill it completely with water and boil for 15 minutes or so.  This builds an oxide layer that'll keep the acidic wort from reacting with bare aluminum.  Once you've got that layer, you're good to go.  Also, be careful when cleaning that you don't scrub off that layer or you'll have to passivate again.


What does this layer look like?  Is it a discoloration?

Offline denny

  • Administrator
  • I must live here
  • *****
  • Posts: 11665
  • Noti OR [1991.4, 287.6deg] AR
    • View Profile
    • Dennybrew
Re: Aluminum or Stainless Steel?
« Reply #26 on: July 20, 2010, 10:51:58 AM »
Yeah, it's kind of a gray film.
Life begins at 60.....1.060, that is!

www.dennybrew.com

The best, sharpest, funniest, weirdest and most knowledgable minds in home brewing contribute on the AHA forum. - Alewyfe

Offline babalu87

  • Brewmaster
  • *****
  • Posts: 831
  • Grand Brewbah
    • View Profile
Re: Aluminum or Stainless Steel?
« Reply #27 on: July 20, 2010, 06:34:08 PM »
Yeah, it's kind of a gray film.

Yes, it almost looks............. dirty

Really.
Jeff

On draught:
IIPA, Stout, Hefeweizen, Hallertau Pale Ale, Bitter

Primary:
Hefeweizen,Berliner Weisse, Mead

Offline thomasbarnes

  • Brewer
  • ****
  • Posts: 413
    • View Profile
Re: Aluminum or Stainless Steel?
« Reply #28 on: July 21, 2010, 04:07:05 AM »
What does this layer look like?  Is it a discoloration?

Silvery gray, slightly dirty. Find a piece of bare aluminum that's been exposed to the weather; it's that color. Scratch that weathered aluminum with the tip of a knife and the color of the scratch is what unpassivated aluminum look like.