Cleaning equipment after using diastaticus yeast

[JockyBrewer]

Funnily enough, it’s only as my Bière de Garde is reaching what I’d normally call the “end” of fermentation (1.010) that I’ve learned about this aspect of diastaticus-positive yeast (I’m using WY-3711). Hmmm.

Wyeast published some a report a few years ago titled “understanding diastaticus” but it’s clearly aimed at commercial breweries, and also sounds very much like it’s designed to limit their legal risk rather than anything else. Basically they say issues in packaging can come from ‘a single cell’ of D-positive yeast… and that the gene is present in wild strains anyhow, which as home brewers we can expect to be swirling around and landing in our FVs pretty much any time.

I think I’ll just give the FV and tap a good dose of VWP after brewing, and mark it as ‘used for Saison’. I must also remember to boil the fittings of the Corny when the beer is finished :-)

I made many beers in a plastic fermenter with Belgian and saison strains before the var diastaticus gene was understood, and they didn't infect other beers with normal cleaning and sanitising.

Brett is a different case, but your regular saccharomyces yeasts should not be feared.

 

[Agentgonzo]

Brett is a different case, but your regular saccharomyces yeasts should not be feared.

Good to know. I have feared the diastaticus yeast contamination as I brew a Saison quite regularly, and only have the one fermenter.

I found a nice way of getting a lot of comfort in killing off any contaminating yeast though:
https://www.thehomebrewforum.co.uk/threads/what-did-you-brew-today.64550/post-1271015

 

[The-Engineer-That-Brews]

Good to know. I have feared the diastaticus yeast contamination as I brew a Saison quite regularly, and only have the one fermenter.

I found a nice way of getting a lot of comfort in killing off any contaminating yeast though:
https://www.thehomebrewforum.co.uk/threads/what-did-you-brew-today.64550/post-1271015

Clever!

 

[Sadfield]

Brett is a different case, but your regular saccharomyces yeasts should not be feared.

I found this on another forum, and haven't had an issue with Brett in FV's or kegs. So far.

 

[The-Engineer-That-Brews]

I found this on another forum, and haven't had an issue with Brett in FV's or kegs. So far.

View attachment 98228

Ten years later (2018), in that report I linked above, Wyeast seemed to have changed their minds:

[…]strongly urge brewers to sanitize with heat whenever possible, as cold sanitizing processes alone may not eliminate a contamination. Among other things, critical points, such as fillers, filters, yeast equipment, hoses, heat exchangers, and all extremities should be treated at 176-194 °F (80-90 °C) for 20 minutes in addition to standard protocols.

Although I rather suspect that this is more about limiting their legal risk than actual necessity (given the number of law suits against breweries for “exploding bottles” at the time )

 

[Sadfield]

You'd hope, if it was critical and not just avoidance of legal liability, that they'd issue clear warnings and instruction on their products.

 

[The-Engineer-That-Brews]

This thread has just reminded me that my local deli owner was shocked last year when a can of beer from brewery “Mad Squirrel” had popped on the shelf (very messy). I didn’t know about diastaticus at the time, but sounds very likely that was the cause.

 

[RoomWithABrew]

Diastaticus positive tends to mean found on PCR/ gene analysis.
Doesn't always mean diastaticus expressive or active.

 

[JockyBrewer]

I found this on another forum, and haven't had an issue with Brett in FV's or kegs. So far.

View attachment 98228

I don't think the individual cells are harder to clean and kill than any other yeast, the issue is in the persistent and pernicious nature of brett when it creeps into those nooks and crannies that you perhaps don't clean/sanitise properly. A fairly small amount into an otherwise finished beer can express itself over time, and given it has a pronounced character you will notice it.

For example, a friend had an issue where he was showing some people his keg setup, and said people merrily swapped disconnects around on his kegs to see how they worked. One of the kegs had a beer that was aging with brett in it, and before he knew it the brett had spread to all his kegs and wouldn't go away with his usual cleaning regime. The solution was to strip all the kegs, posts and disconnects down into the smallest pieces possible, clean with percarbonate and then sanitise and let dry with iodophor.

I'm not so worried with regular sacc yeasts as, even when diastatic, a small amount of residue hidden in a keg doesn't seem to be able to take over a finished beer. The fermenter could be a different case though - I guess if you had some diastatic yeast residue in there and then pitched a slow starting yeast that maybe you might get some of the diastatic yeast character. I always do a complete strip down, disassemble the tap etc on my fermenter.

 

[Sadfield]

The solution was to strip all the kegs, posts and disconnects down into the smallest pieces possible, clean with percarbonate and then sanitise and let dry with iodophor.

Exactly, Brett isn't any different if you clean your kit properly with a Alkaline cleaner, and then sanitise. As per the the quote from Wyeast.

Corny kegs should be stripped down for thorough cleaning.

 

[The-Engineer-That-Brews]

Exactly, Brett isn't any different if you clean your kit properly with a Alkaline cleaner, and then sanitise. As per the the quote from Wyeast.

Corny kegs should be stripped down for thorough cleaning.

^^ this!!
I used to just scrub my Cornies out with Percarbonate then pressurise the keg and blast it out through the disconnects and prv; and to be fair I never had a problem - but recently I started removing the posts and dip tube, and soaking them separately. It actually makes the keg a lot easier to clean without having to work around the dip tube, and I’m sure it makes for a more thorough clean

 

[The-Engineer-That-Brews]

The thing I’m never terribly convinced I’m cleaning sufficiently is the inside of the beer lines… I always pump hot cleaner through it for ten mins or so after a brewday, but I suspect in reality you get a bio-film building up over time. I should probably replace it more often than I do!

 

[JockyBrewer]

The thing I’m never terribly convinced I’m cleaning sufficiently is the inside of the beer lines… I always pump hot cleaner through it for ten mins or so after a brewday, but I suspect in reality you get a bio-film building up over time. I should probably replace it more often than I do!

Good quality beer line like from Valpar/Micromatic has a very smooth inner surface that makes it difficult for biofilm to build up, and will last a long time.

Up until recently I've done the same as you - run some hot percarbonate through it when cleaning a keg. I recently stuck some purple beer line cleaner through it and that didn't pull seem to pull any nasty stuff out, so my cleaning regimen was working... but it was noticeable that the lines looked brighter afterwards, so I decided to stick to the purple line cleaner in future.

I bought one of kegland line cleaning kits, which makes cleaning a doddle.