Build your own caustic?

[burlybeer]

Not being in the brewing industry anymore, I no longer have access to some of the necessities that I was used to using...namely chlorinated caustic. I do however have access to Red Devil Lye and chlorine bleach, etc.

2 grams anhydrous Lye in 100ml water gives me a 2% caustic solution.

If I wanted to build my own chlor-caustic, how much of a typical 5% Bleach solution (ie Clorox) would I need in that 100 ml. I'm not sure of the percentage of chlorine that was in the built product I was using (Loeffler)

Also, what would/should I use as a wetting agent, or will I need one.

Thanks

[gitchegumee]

We used to build our own caustic using 50% NaOH, 5.25% NaClO, and sodium gluconate as a chelating agent--sorry I don't have any measures for the ingredients. I know it's important to limit the NaClO to a small amount to keep stainless from pitting. Also know that using the three chemicals to build your own will very closely approximate commercial cleaners. Good luck.

[beertje46]

Couldn't you buy some from one of your local breweries? Assuming you're in the Atlanta zipcode still; Sweetwater, Atlanta Brewing.

[gitchegumee]

Actually, the Atlanta Brewing Company is where I learned to build my own caustic. They might still do things this way, but it's been a while and they may use a prepackaged product now. Give them a jingle to find out. Good luck.

[burlybeer]

I answered my own question.

Malting and Brewing Science Vol 2 indicates a max of 250 ppm for 304 stainless. 30ml/gal household bleach will give me a little under 200 ppm.

I am on good terms with the folks at ABC (and yes Phil, they use prebuilt product now), this is mainly an exercise to help some homebrewers and myself in a pinch.

Thanks!

[gitchegumee]

So now that I'm ready to clean tanks in a new brewery, I find that I only have access to simple chemicals. No prebuilt non-caustics, acids, or sanitizers. Looks like I have to buy NaOH and work from there. Anybody else making their own blends? Sure would like to know how to make a non-caustic. I hate NaOH. And a how-to for nitric/phosphoric would be great. Any help?

[kai]

Phil,

Why do you hate NaOH? Is it the temperatures required? The personal danger?

[Larry Doyle]

I think beer guys should make beer and chemical guys should make chemicals and never the twain shall meet.

[gitchegumee]

Larry, I'll have to respectfully disagree. A good brewer should know water chemistry, organic and inorganic soil removal, sanitation, health, and environmental aspects of cleaning chemicals. Knowing sequestering agents, chelating agents, wetting agents, surfactants, dispersants; how and why they work, when to use them, how to use them effectively and safely is part of a good brewer's job. Otherwise, what do we do? Rely on a chemical supplier's sales rep to tell us what to buy and how to use? And I don't like sodium hydroxide both because it usually requires heat to work well, and is highly aggressive to humans. PBW or Bru-R-Eze is so much better in my opinion. So how to make something similar?

[campbell.brian]

Seems there is new life in a three-year-old thread.

I must agree with gitchegumee that a good understanding of cleaning chemistry is important in a brewer's tool box.

I also agree with Larry Doyle that chemical manufacturing and blending should be left to its own industry. The purchasing power of a large chemical company allows them to sell built products for cheaper than a brewery could make them.

Thirdly, I think a good understanding of the unique soils, equipment, and other challenges for brewers helps distinguish brewery-specific chemical manufactures from general industry cleaners.

Please do not be fooled by any implied safety of Sodium Metasilicate-based cleaners. These products do not carry a Class 8: Corrosive label because of DOT classifications. Products containing 30% Sodium Metasilicate are exempt from labelling--this is because they are safe for trucks, not because they are safe for human contact. A bag of Sodium Metasilicate will carry a Class 8: Corrosive label, and any MSDS for these products will have a warning to avoid contact with skin. Always read and obey the MSDS from your chemical manufacturer.

Sodium Metasilicate is less alkaline than Sodium Hydroxide, but more expensive per pound. This will make it less agressive on skin, but will ultimately require more of a product that is already more expensive, as alkalinity provides the bulk of the cleaning.

Powdered products also limit the amount of chemistry that can be built into a cleaner. Powdered Metasilicate cleaners often use EDTA (enviromentally unfriendly) as a sequesterant and do not have any surfactants. Sodium Hydroxide requires only a pH adjustment to be as benign as salt water. This is not the case with Metasilicate.

Another disadvantage of Metasilicate is the potential for scaling of equipment. I am often contacted by brewers looking for a stronger acid cleaner to remove stuborn "beer stone" that turns out to be silica scale. Sodium Metasilicate can leave silica scales on equipment if it is allowed to dry. Cleaners containing Sodium Metasilicate should never be allowed to dry on equipment. This includes soaking applications in which the equipment is not completely submerged, as rings of silica can form at the liquid level.

One advantage to powdered caustic alternatives is that the other 70% of the product is usually Sodium Percarbonate--a readily available oxidizer. Oxidation drastically improves the performance of alkaline cleaners. Sodium Hypochlorite is added to caustic cleaners to provide oxidation, at the expense of making them chlorinated.

Another source of oxidation is to use a non-chlorinated caustic and add your own oxider when preparing the CIP solution. In our case, this is done with the LERASEPT O and is the recommended regimen for our customers. This product performs best at 160-180°F.

...I don't like sodium hydroxide both because it usually requires heat to work well....

The performance of caustic will improve significantly above 130-140°F.

Remember that Temperature is a key ingredient in cleaning performance along with time, chemical concentration, and mechanical energy. In heavily organic-soiled equipment, such as the brew house, higher temperature cleaning solutions should not be a challenge.

Also, interactions with any CIP should be minimal. Donning boots and a chemical suit and climing into a vessel is manual cleaning--not CIP. Nor is scrubbing the inside of a vessel with a pole brush. Brewery vessels are considered confined spaces by OSHA, and are considered a hazardous atmosphere when they contain cleaning products. If this is required for the interior of a vessel, it would make sense it should be required for the inside of your heat exchanger--where solution moves from high flowrate and low surface area to high surface area and low flowrate. If you are scrubbing your vessels manually, are you breaking your heat exchanger as well?

[Larry Doyle]

Its all coming back to me. My philosophy of "brewers should make beer; chemical guys should make chemicals" came from none other than Dirk Loeffler.

[gitchegumee]

Brian, I agree that metasilicates can leave scale, and particularly a brownish oxalate "bronzing" in tanks. And that the advantage of cooler metasilicate cleaning can be undone by the follow up warm, strong acid to remove this. Pricing and other disadvantages I can live with in favor of safety. (There's no comparison between safety of powdered PBW and powdered/anhydrous NaOH--or even liquid 50% NaOH.) After years of using both, I like the safer product. Particularly for my employees. And at the low temperatures and CO2 environment of a serving tank in a cold room of full serving tanks, caustic really isn't an option.
My reason for bringing this all up is not to save a dime by reinventing the cleaning products; it is because I do not have access to properly built cleaning chemicals for the brewing/dairy industry. Plain caustic, nitric, and phosphoric is what I can get, along with some other agents. So I'm after ideas on how to prepare a safe and effective cleaner from scratch.
For the brewhouse, fermenters, and PHE, I'll use NaOH and RO water perhaps with a bit of bleach at warm, post-knockout temperatures. For the cold room serving tanks, RO with a nitric/phosphoric blend. But what weight percents, and with what detergents & dispersants? All will be used with CIP sprayballs, so I'd like a low-foaming product. I guess research and careful trial and error are going to guide me. Thanks for your help!

[campbell.brian]

gitchegumee,

Have you considered acid-only cleaning as an option for your bright beer tanks?

I recommend speaking with Dirk about building cleaners with what materials are available in your area. You may wish to wait until after follow-ups from the MBAA convention are completed.

Sincerely,

Brian Campbell