stubborn krausen ring
Looking for some more experienced guidance here...
I've got a 15bbl fermenter that I've been routinely overfilling a bit, and I'm finding that the krausen "crown" left behind on the tank (a ring that covers the entire dome) resists all cleaning efforts with the removable spray ball. I just don't think it's hitting the tank that much above the level of the ball, though it is wetting it.
It requires more than an hour of hand scrubbing - standing on a ladder. This is not how I wish to spend my day.
I'm thinking that I probably need to replace this spray ball with something that has better 360deg coverage, but it occurred to me that the problem might be because I've been over filling the tank lately.
Last edited by Sir Brewsalot; 07-21-2005 at 11:14 AM.
Where are the holes focused on your spray balls? If there aren't enough holes on the top of your ball, taking the ball out, and drilling a few more may help. I have 15 BBl fermenters that I fill to the top as well. I get massive residue on the top dome. All my spray balls have almost all the holes on the top hemisphere of the spray ball. I don't have any problem cleaning it via CIP as long as all the CO2 is purged from the tank and the caustic is hot enough.
If you change spray balls, and you have some extra duckets, look into the "Tofte Jorge (sp?) Sani Midget" sprayers. They are a little pricey, but if you put those puppies in the tanks they will clean everything. I know another brewer that has those. If they were in my budget right now, I'd replace all my spray balls with those.
Last edited by Triose; 07-21-2005 at 12:48 PM.
I agree it is a good idea to check your spray ball for clogging. An easy way to check is look at the spray pattern while rinsing the tank with water. That should tell you everything you need to know.
What chemical do you use to clean your tank with? Are you using it at the recommended strength/concentration and temperature?
I would recommend using PBW with hot water-your brandhefe will dissolve and so will your headache.
I've used PBW, It's nice, but a little wimpy for tough residue. For real cleaning power use a Sodium Hydroxide Caustic, at 180 degrees, at a 5% solution. "Excel APA" is the brand I use. I order it from "Westmar".
Remember to purge the tank of CO2 before using any caustic, if will make the caustic much less effective. And remember that you should heed all safety precautions outlined in the MSDS when using this stuff.
I like to keep a bucket of mild acid solution made up in case I get caustic in my skin. It's hard to rinse off with water alone.
Your spray ball should not have a spherical coverage, but instead a hemispherical-up pattern. Small fermenters are best cleaned with the cleaning solution sprayed gently and evenly up on the dome, cascading down the sides. Blasting the solution has no advantage. The Toftejorg devices are actually cleaning "machines" that blast a pinpoint spray while rotating in such a way as to hit every surface in the tank in due time. They work extremely well, but are priced for larger installations. The first thing I would do after checking the spray pattern with water is to involve your cleaning chemical supplier/technical representative. Plain caustic soda, NaOH, is not as effective without supplemental agents like sodium hypochlorite (bleach) and sodium glucanate. Other additives may be helpful depending on your water supply chemistry. There are many companies offering all kinds of great products and they know that they must perform well to keep your business. Ask him/her for several samples of fermenter cleaning products and invite them to witness your cleaning regiment. I would avoid products that require hot application. Warm-yes, hot-no. If you accidentally leave the fermenter jacket on, you could warm the other fermenters. It is also best not to subject the welds to large temperature transients. And you will use less water to warm up/cool down the fermenter, as well as less energy. As for safety, a fermenter is a confined space as defined by OSHA. It is best never to enter any tank. I agree with Tomas that with any alkaline cleaning product, you should have a source of dilute acid to rinse skin with. Beer works very well, and is easy to get at from a zwickle. No matter how tough the residue, it should be gone in 30 minutes. Follow with an acid to remove beerstone and to neutralize any caustic clinging to the tank-NaOH is difficult to rinse away completely using water alone. Cleaning may be the most important task in a brewery. Contact many chemical suppliers, read as much as you can, and experiment. You should be able to keep outside your tanks soon. Good luck! Cheers!
I have on occasion added bleach to the caustic. It does give it a boost. However, for my krausen rings, it's always been unnecessary. If you don't want to deal with hot temperatures, you can try potassium hydroxide rather than sodium hydroxide. But I still think that sodium hydroxide, at 180 is best.
If your tanks were made well, the hot temps won't bother your welds at all. But like Gitch said, remember to turn off your glycol to that tank, as you could warm up the whole system..
Also, after the Caustic rinse, I hot then cold rinse, then recirculate a mild acid sanitizer through. Remember to open your sample valve or your tank will implode when going from hot to cold. Ay De Mi!
Perhaps your spray ball needs to be higher in the tank? More pressure to have the spray reach farther to the tank walls? It may be possible for you to get an expensive tank cleaning nozzle that can be moved from tank to tank and save a zillion bucks. Beware some spinners don't work so well if not in the vertical position they recommend. A couple hundred bucks for a good tank spinner is worth the value of a bad batch from bad cleaning.
Ferm-Cap will help not make the ring such a mess in the first place.
Thanks everyone. You definitely answered my question about whether it's okay to overfill the fermenter as I have been doing...
The current rotating spray ball is a "full spray", both up and down. Clearly wasting spray force AND chemical coverage on the lower half. At $412 a pop, I think the sanimidget seems a little pricey for my modest budget - but I haven't checked alternatives yet. I think I can hit those rates (25gpm/30psi) w/ my little C100, but I need to look that up.
The two 7.5bbl fermenters clean up fine with their installed spray balls, so it would be used only in this tank - maybe in finished product tank too.
Head is not clogged, as it is removable (nice cam/groove fitting) and inspected w/ each use. Chemical is PBW at published "fermenter strength" and temp (after a preheat of course). I'd like to avoid caustic if I can swing it... am I nuts to think I can?
Try http://www.lechlerusa.com for spray heads. You can also try: http://www.cloudinc.com/svru.htm Both companies are very responsive.
I would continue to use PBW for your fermentors unless you have a way to recycle your caustic. There is less COD in your wastewater if you use PBW, something that may help you if your sewer board comes after you. Caustic is great I have used Ecolab's Avoid, and Diversey's CIPTON, I like the Diversey product a lot. Regardless of other posts, in the case of caustic, higher concentration is not better. Anything over 2.5% is wasted chemical. This has been proven by the large brewers over the last 20 years. Most large breweries do not go over 145°F either.
The down side of PBW is using an acid cleaning step.
You have provided a good lesson and reminders for us all!
You can probably find a welder to quickly and easily seal up the holes in the lower hemisphere of your sprayballs. I'm sure it would be far cheaper than replacing the balls.
I have read in a book that caustic is not that much more effective at 180 than it is at 135. But I have found that in my personal experience, it works much better and much quicker at the higher temps.
Also, you are right about recycling caustic, I have a CIP tank that it goes back into, and during a cleaning day, I'll pipe it around to different tanks, heating it in the kettle if necessary.
I have never tried it at 2.5%. I have always mixed it up in my CIP tank according to my manuf. instructions at or near 5%. You may also try recirulating plain water for a while before you use chemicals, that can save on chemical use.
But in the words of brewers everywhere, "whatever works amigo".
Last edited by Triose; 07-27-2005 at 01:28 PM.
I've also found that a stubborn krausen ring will always respond to a little attention from a high-pressure water cleaner nozzle aimed through the manway door. Just soften up the ring with some hot water first. Then return to the caustic wash etc. regime , and this seems to work fine... (Idea thanks to one of my bar staff)
Well, I had much more success by hitting it with hotter water first, then running my typical hot PBW cycle on it - at the upper end of the recommended temp range, and for a bit longer. Did the trick nicely.
Spray ball is a spinning 360deg pattern model, btw...
No, I'm not setup for caustic-reuse without a heated reservior and such. I do get some secondary use from the PBW though, pumping onto the screens in the mash-tun for a soak.
Not exactly about sprayballs...
I didn't see anybody talk about recycling PBW - can this be done or is PBW only effective for one use?
Also, how long can a caustic solution be recycled for? Is it until the pH drops to a certain level or just a certain amount of time? If it's based on the pH, at what pH is caustic no longer effective?
Lastly, I was thinking about using iodophor instead of acid for sanitizing. Can I get away with that? What would be the downside? Can iodophor be mixed with PBW solution or caustic to bring pH down to enutral for sewering?
Sorry to be so dense - chemistry was never my thing.
Don't know about PBW, but your caustic solution may be reused until it drops in pH. It is NOT time based. The exact pH, I don't know. You will know when it quits cleaning. Also there is a phenomenon known as saponification that happens when mixing a caustic solution with lipids (fats). These lipids are present in a krausen ring. It will foam up your caustic something fierce. Used to take me a half hour just to wash the foam down the drain when my caustic quit working. Iodophor is an excellent sanitizer. It is an iodine/phosphoric acid mix. The iodine is made more effective against bacteria in an acidic environment. Every sanitation option has ups and downs. Iodophor is effective against bacteria and wild/cultured yeasts, but is delicate. Like any sanitizer, it should not be reused. Instead, I used the leftover Iodophor in a brink where I kept my clamps, gaskets, fittings, and yeast transfer hose. I recommend using an acid rinse after caustic cleaning followed by the sanitizer. Use a clean water rinse after each chemical wash. You should not use Iodophor directly after the caustic. It will neutralize the solution and render it ineffective. As far as sewering goes, Iodophor will not totally neutralize caustic. Yeast, DE, beer, and almost all other brewery waste will. Hope this helps. Cheers!
I'm a little late to this thread, but another thing that you might consider is using something like Fermcap to keep the foam from forming and getting all over the top of your fermenter. I was filling fermenters up to the top and having all kinds of trouble until I started using it, and presto! Just a little ring of spooge at the level of the top of the beer. No more blowoff mess, either. Best of all, no adverse effect on the beer, either.