Just wondering how each one of you control the growth of unwanted bacterial growth in your fermentation tanks? What are your methods of controlling it? What methods of cleaning and what do you use to clean with? We know bacteria is everywhere it comes on our grains and is in the air.
How often do you sanitize, after every mash run? Do you use a steam cleaner with an acid solution?
Reply:Just wondering how each one of you control the growth of unwanted bacterial growth in your fermentation tanks?
Rich- I'd be interested in your cleaning protocols. Also still cleaning.
I assume you are referring to growth during a ferment? I have always followed the basics;The vessel must be of a sanitary design, hence I am not big on wood fermenters.
Clean everything, with lots of hot water. Few bacteria will establish without an organic substrate. If its clean thats most of the battle. I believe as an industry we have become too dependent on chemical sanitizers, in lieu of good cleaning practices.
We always steam clean after every batch, and leave the vessel clean and dry before the next run.
We will CIP caustic every couple of batches to clean out the hard crud. We follow this with a citric pacification rinse, then hot water rinse.
As a rule, we do not chemically sanitize. Steam tends to do a better job, and its compatible with our organic processes.
I firmly believe the best way to prevent bacterial infections is to 1) ensure the environment is not to their liking 2) drive them out through competition.We tackle the environment by watching the pH closely, and tend to run it as low as practical
We try to establish a strong ferment as quickly as possible, and with a minimal lag period. Once the yeast is up, most bacterial infections struggle to take hold.
[*]Ensure a speedy complete fermentation
[*]Once fermentation has completed, move to distillation as quickly as possible. The most vulnerable is stagnant wash.
I am happy to post our cleaning protocols if it helps.
We use a local winery cleaning product called 'CleanSkin'. It is alkaline based and organically approved. AiRD are the manufacturers at: http://www.airdchemistry.com/
Follows is the protocol we use for fermenters and stainless stills, hoses and pumps. We do not use an alkaline agent on the copper stills, I will post that protocol later.
Stainless steel: Eco-Sustainable protocol
This hygiene procedure for stainless steel and other accepted wine storage contact and associated surfaces involves using a 2 step method with interposed potable water rinsing.
Step 1 - Cleaning the surface, and then, Step 2 - Disinfecting the surface.
Surface wine soils
A volume of hot water (70-60°C) is circulation pressure sprayed over the acidic soils, whereby over a short period of time much of the acid soil (predominately wine tartars), is degraded and dissolved into the hot water which attains an acid pH. A final process of detail cleaning of any remaining degraded tartar and colour using a reduced quantity of alkaline material in a hot aqueous solution in a circulated pressure spray is applied. In this process, as in the conventional method, the commencing pH of the alkaline solution is reduced by the acid soils.
Refer to CIP-All wine acid soils 1 - 50mm depth
Material for surface disinfection
Surface disinfection is executed with the use broad spectrum sanitising liquid as part of a circulated cold aqueous solution, pressure sprayed over thoroughly pre-cleaned surfaces to eliminate microbial pathogens before re-use.
Refer to SIP-Clean Surfaces
No wine soils-surface hygiene re-established
This occurs where a surface which had been previously cleaned has been left unused and exposed for a period of time and has to be hygienically refreshed by removing incidental organic soil, off-odour or microbial pathogens before re-use.
Refer to CIP+SIP-Fine bottling tartar and wine films.
Material for cleaning and disinfecting wine and organic exterior surface soil and film
A biosafe, peroxyalkaline detergent powder in a warm-hot aqueous solution to detail clean and sanitise these surfaces without odour in a single process.
Refer to CIP+SIP-Wine and exterior surface soils and films <2mm depth.
The following charts are offered as a guide:
CIP="Cleaning" in place (system), SIP="Sanitising" in place (system)
CIP - All wine acid soils 1 - 50mm in depth
Each time after surface is soiled
60 - 70°C
Circulatory pressure spray
15 - 30 min.
Follows the use of hot water
2.0 - 5.0% of Hot aqueous soln.
60 - 70°C
Circulatory pressure spray
15 - 45 min. or until clean.
Cold potable water
SIP - Clean surfaces
LINVASAN or PERCITRA
After cleaning before re-use
0.75 - 1.25% of Cold aqueous soln.
Circulation pressure spray
< 5 min.
I regards to this discussion on CIP'ing your tanks. You should also check the specs of your sprayball and be sure you have enough pump stregth to provide the necessary mechanical action during your CIP. What type of sprayball design are you using? you can conserve energy by using less hot water if you have adequeate mechanical action from the sprayball as well as proper titration levels of your chemicals and good contact time of the chemicals against the surface. Regarding using sanitizers or steam, there are a number of successful and very large brewers that simply do a caustic & acid cycle with no steam sterilize or chemical sanitize. If you have done a proper cleaning and there is nothing on the surface on the stainless you don't have a need for a sanitizer. But, if you are cleaning that tank and letting it sit for a week or two......then I would consider a hot rinse or "maybe" a steam sterilize.
Have you plated and id'd this bacteria? Is this a pedio infection?