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Ongoing Diacetyl ? off flavour

Discussion in 'General Brewing Techniques' started by Bandit24, 24/7/18.

 

  1. Bandit24

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    Posted 24/7/18
    I've been getting an ongoing off flavour, and I'd hugely appreciate any thoughts/ideas on what I'm doing wrong.

    Latest:
    WHITE IPA FWK (20L)
    Split into 2 x 10L batches
    OG 1042
    Used pure o2 for 90 seconds in each batch
    Batch 1-WLP590 French Saison (18 days old when pitched) - Ferm temp 22c
    Batch 2-WLP007 Dry English Ale (19 days old when pitched) - Ferm temp 18c

    Both batches, 1014 after 4 days, currently at 6 days

    Saison tasted amazing at Day 3, fruity, and beautiful saison flavour.
    wlp007 batch just tasted ok at Day 3, nothing off, just average.

    Day 4 (When gravity samples taken), a distinct sweet, maybe butter/butterscotch kinda flavour has become evident, it kinda reminds me of unfermented wort. It sort of matches to the descriptor for Diacetyl, but really I’m not 100% sure, as I am inexperienced in beer tasting.

    Day 6, haven’t taken another gravity sample yet, but the flavour described above has pretty much completely taken over both beers, even the Saison yeast profile as almost completely diminished.

    Previous to these above batches, I had 3 x full 20L FWK batches with similar taste.

    Pale Lager FWK - 1044 > 1008 - using WYEAST 2112 (6 week old yeast) - aerated by hand - ferm temp 19

    US Pale Ale FWK - 1050 > 1008 - using WYEAST 1272 (4 week old yeast) - aerated by hand - ferm temp 19

    UK Pale Ale FWK - 1044 > 1010 - using WYEAST 968 (8 week old yeast) - aerated by hand - ferm temp 19

    In all 3 beers, they are pretty much the same as my latest batches, the flavour is the same as described above, but in varying levels across the 3 batches, but in all cases, they taste pretty shit and I am struggling to drink them. The Pale Lager is almost 2 months old in bottles and hasn’t improved at all, probably getting slowly worse if anything.

    Obviously the first thought after the above 3 batches is Diacetyl. And after reading more about yeast pitch rates and oxygen, I decided I had both under pitched and under aerated and caused Diacetyl due to yeast stress.

    So I got myself a Pure o2 kit, and decided to try 10L batches so I could ensure I was pitching enough yeast (without doing starters, which I have not done at all yet), I also bought some of the freshest yeast I could find in store.

    I am brewing in a temp controlled fridge. I used 2 x brand new 15L fermenters for the split 10L batches.
    I am thorough with my cleaning and sanitising using Sodium Perc and StarSan.

    I am not just being fussy with flavour. Although not completely off, these beers are drinkable to some degree, but are just not enjoyable at all. I struggle to get through a long neck once opened, and am really avoiding drinking them at all.

    I have tasted beer that the LHBS store has whipped up with a kit and kilo and dry yeast, fermented in the back of the shop with no temp control, and that stuff is miles better than what I am producing.

    I previously went through the pink yeast debacle described in this thread: https://aussiehomebrewer.com/threads/frequently-asked-questions-for-the-new-brewer.9233/page-18

    I believe I stopped the pink yeast/infection/whatever it was, by ditching all my fermenting gear and starting fresh and nuking my fridge with sodium perc and starsan, which I now do after every batch just to be sure.

    In 12 months of brewing, I am up to 16 batches, and I’ve had only 3-4 “successful” batches, and those were early on, (FWK’s) using dried yeast without rehydrating, they weren’t great either, but there didn’t seem to be any off flavours, just boring beers as I wasn’t doing much with them back then.

    The only things left that can be possible problems as far as I can see:

    1) I have just found out that StarSan can be infected if there is a crack in the bottle. My lid is cracked and has about a 2mm gap that could let air in. It has been like this for many months (maybe even 6-9 months). I am going to ditch this bottle and replace it to make sure, and even though it seems highly unlikely, could anyone see this being the root of my problems?

    2) My fermentation fridge. I bought it refurbished from the manufacturer, which was basically brand new. It’s a Haier, pretty large fridge-only kinda deal. I honestly don’t know what could be wrong with it to cause repeated off flavours, but I have read about things like air conditioners causing repeated infection.

    3) The shed I have the fermenting fridge in. I usually do all my cleaning/pitching/dry hopping etc in the kitchen, but the fermenting fridge is in a small outdoor shed/demountable type thing, that is shared with a dog, and has a permanently open door to the back yard. It’s not especially sanitary, but I do make an effort to try and keep it clean, and not to disturb any dog hair or dust before opening the ferment fridge. I am a sucker for “checking on” and tasting my brews though, so the fridge door does get opened a lot. I use glad wrap for fermenting, then half screw the lid back on (with the glad wrap still on) when cold crashing. Any chance of something in this shed causing an issue? Wild yeasts? anything I can do/look for/avoid?

    Any ideas or help would be greatly appreciated.

    Thank you for listening to my extremely long sob story <3
     
  2. dibbz

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    Posted 24/7/18
    > I have just found out that StarSan can be infected

    It's literally acid
     
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  3. Bandit24

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    Posted 24/7/18
    I assume that means StarSan can't be infected? I have definitely just read it somewhere, however happy for that theory to be proven wrong so I can cross it off my list
     
  4. MHB

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    Posted 24/7/18
    There are usually two causes of Di-Acetyl (more properly VDK's) are Yeast and Bacterial Infection.
    Unless you are doing something really out of the ordinary I think from what you have written, it probably isn't the yeast. To make sure if its wrong to assume you are using fresh yeast and not trying to get a ridiculous number of brews out of one batch let us know.

    Which leaves Bacteria, the bugs that cause VDK's can be very tenacious, hard to kill and frustrating. They are also extremely good at penetrating plastic.
    Considering where your at and what you have invested I would get a new fermenter and all its parts, use nothing that has been exposed to other brews (taps, airlocks hoses stirrers...)
    If you cant do that, soak everything in hot water and bleach (better yet IodoPhos), leave for a couple of days, do a basic K&K brew and see if it shows the same signs of infection.
    Good idea to sanitise the whole brewing space and the inside of your fridge with either 70% Alcohol and water spray (Metho and water, no Smoking OK) IodoPhos or even Bleach, just take appropriate care to have eyes and a respiratory system left when you finish (were eye protection and a respirator).
    Can be dam frustrating but work at it systematically and you will win.
    Mark
     
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  5. labels

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    Posted 24/7/18
    A very comprehensive question with lots of information. However, very difficult to answer in a brewing forum. Firstly, even you're not 100% sure diacetyl is the problem but it seems most likely, secondly there are many pathways to diacetyl. Although the majority are fermentation related, wild yeast infections can produce huge amounts of the stuff.

    In my opinion, you're best chance of finding an answer is by networking with other brewers in your vicinity - a brew club perhaps and getting an opinion based on tastings and experience of the other brewers. I don't think you're going to find an answer here.
     
    Last edited: 25/7/18
  6. Bandit24

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    Posted 24/7/18
    Thanks for your help Mark.

    At this stage I'm using fresh yeast and only using it once. Looking at my pitch rates and process, would you say I should have something drinkable by now, and therefore this is looking like an infection issue not a yeast/stress issue?

    Out of the 5 batches with this assumed Diacetyl infection, the first 3 were in a brand new 25L fermenter (with all new fittings etc), and the latest split batch in 2 x brand new 15L fermenters (with new fittings). Nothing else previously used in the brewing process was used on this latest split batch in the 15L fermenters. Maybe except simple things like scissors to cut the yeast packet open (which are brewing only scissors and sanitised before use).
    You would have to assume therefore the infection is finding its way in regardless of my equipment and process, and I need to completely nuke the space and everything in it with cleaners as you suggested.

    The only consistent things amongst these batches (and also previously), were basically the cracked StarSan container (now debunked), fermenting fridge, and backyard shed. Would you say in general, an old demountable/shed that houses a dog, and a fair bit of other junk, open door, rundown - is just a bad place for fermenting, even if fermenter is appropriately sealed inside a fermenting fridge?

    I'm happy to invest in a stainless fermenter if the consensus is it's much less likely to be infected? (if proper cleaning/sanitation processes are followed of course).

    I'm thinking of trying the next batch inside the house instead, it will have to be heat belt and temp controller only, and shouldn't get too warm where I am at this time of year.
     
  7. Bandit24

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    Posted 24/7/18
    Agreed, very difficult to get a true answer to something like this on a forum. And I had been meaning to find the local group and explore that way and will do soon, however I thought it was worth posting up and seeing if anyone did have any ideas I could start working on now, so I can keep brewing in the meantime!
     
  8. MHB

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    Posted 24/7/18
    Dog and old outdoor shed are a pretty scary combination.
    Knew one guy who tried to brew in an old cattery - about a dozen brews before we nuked the room and replaced the carpet with lino - fixed it.
    Everything else sounds like it should be giving good results, so I think bringing it indoors would be a good call. Avoid heat belts and plates if you can, use a neutral Lager yeast (say 34/70) or just wrap a towel around the fermenter with a temperature tolerant Ale yeast.
    Still a good idea to go insane with the cleaning.
    Mark
     
  9. Danscraftbeer

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    Posted 24/7/18
    Re check all procedures. Are you up to standard? For what the professionals would do?
    All new fresh cleaning and sanitizing solutions?
    I will use solutions for a while they are good. As long as they are kept in uncompromising ways.
    Its a judgment thing. When in doubt chuck it out. Make fresh as the professionals would always do because they can not risk buggering up any brew. So do what they would do.
     
  10. Fro-Daddy

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    Posted 24/7/18
    This might seem silly, but how about the cleanliness of your hands when working with the equipment?
    I agree with changing the brewing environment for a test though, seems like equipment should be ok.
     
  11. Bandit24

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    Posted 24/7/18
    I'll give indoors a try with a basic K&K 34/70 recipe and see what results I get.

    Why do you suggest not using heat belt/plate? Are you saying that in general they are bad, or just in this scenario..and why?

    I think I'll get a fresh Bunnings fermenter to be sure for this batch to make sure.

    Another question related to this - when I've drilled holes into cubes/Bunnings fermenters before, I got pretty jagged results around the hole, looked like good hiding places for bacteria. I tried to smooth them out but I was never satisfied. Anyone got any tips on how to do this successfully? Is there some kind of specific drill bit I should use? I'm not great with tools.

    And re: stainless fermenters, as long as normal procedures are followed, is the general consensus is that they are more resistant to bacteria?
     
  12. Bandit24

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    Posted 24/7/18
    Do you think having the StarSan lid cracked open could effect the effectiveness of it in any way? For $10 or whatever StarSan is, I'm happy to chuck it and start again to be sure, but still curious about this one anyway.

    I've had to go through a check of my cleaning procedures already, when I was previously getting a seemingly different infection as mentioned in the thread above. I completely overhauled everything then, and now getting this new infection. I don't know if I'm up to a professional standard, but I'm basically doing everything that is possible in my current house.

    Before this 12 months of brewing, I have actually had a couple of attempts at brewing over the years in different houses, I only brewed say 3-5 batches on each attempt, all kit and kilo, sprinkled dry yeast, and don't remember ever having infections, or any ongoing problems like this. I remember pretty boring beers, that seemed clean however, and maybe 1 or 2 dud batches due to no temp control, and I was probably just using the "all in one cleaner and sanitiser" that came with the fermenter kit. At this house I've stepped up my knowledge hugely, using the right chemicals, way better ingredients, temp control, being as thorough as I can, up to about my 7th new fermenter, and basically had ongoing problems for 12 months, which is leading me to think it really has to be an external factor like the space I'm fermenting in.
     
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  13. Bandit24

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    Posted 24/7/18
    I just wash my hands with household hand soap before starting, but usually need to pop in and out of the kitchen to the shed for a couple of things while brewing, I couldn't guarantee I'm keeping them 100% clean during the process. I don't have a physical job that gets dirt or grease on my hands or anything (I basically work on a computer at home). Either way I didn't know there could be an issue here, what is the recommended process?
     
  14. MHB

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    Posted 24/7/18
    On heat plates and to a lesser extent belts they are often heating the yeast, this accelerates any breakdown which can lead to off flavours, plates are really bad. You usually get better results brewing cooler. I used to (back in my shop owning days) often put a glass fermenter on the front counter, it brewed out just fine without any heating even in the middle of winter, looks good to, bit like a lava lamp.

    For drilling tap/bung holes I always used a spade bit (the flat ones with two little cutters on the outside edge). This type and size.
    upload_2018-7-25_8-42-2.png
    The other tool I found handy was an old soldering iron, I have a 2000W job, it takes a piece of 1/2" copper tube into the head holder, get it hot and just punch out the plug, it self seals the edges of the hole at the same time. If your hole is a bit raged you could clean it up with a sharp knife then fuse the surface with a small gas flame (takes practice and not recommended for tooltards).

    SS equipment is the nuts, but it wont fix all problems, if you are getting bacteria or as labels said wild yeast, better to fix that first and be sure you want to keep brewing before making a big investment.
    Mark
     
  15. Bandit24

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    Posted 25/7/18
    Re: heat belts - fair enough, but how do you really control temperature then? Just a fridge and temp control? What about when it gets too cold? Or are you saying in a climate like Wollongong, brew lagers in winter and then ales in summer? It seems a lot of people use heat belts and plates, is it better for example to hang the heat belt in the fridge (which I read was risky as they need to dissipate their heat onto something)? Or are you just saying heat in general is bad? I was under the impression yeast fermented too low in temp (below its optimal temp range) would be stressed, or not finish fermenting?

    Re: Drill - Thats exactly what I used but the holes always seem to come out ragged around the edges. On a regular open style fermenter, I'm able to get in with a box cutter and at least improve it, but on Bunnings fermenters/Cubes with small openings, how the hell am I supposed to clean it up from the outside, when the raggedness is on the inside?

    Re: SS - based on the track record and results I've had, believe me if I wasn't in this for the long haul, I would have stopped already. I definitely will fix this problem before investing in SS, but good to know for the future SS is the way to go.
     
  16. MHB

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    Posted 25/7/18
    If you put a small fan in your brewing fridge you wont need a heater. A fridge is a well insulated box, a brew produces heat and so does the fan. Even in the middle of winter the fridge will kick in occasionally to get rid of excess heat.
    The other advantages of a fan shouldn't be understated; they stop thermal layering (the fridge being hotter at the top than the bottom); improve the rate of cooling (moving air takes the heat out of the fermenter faster keeping your brew closer to the set temperature); reduces the size of the cycle range between fridge on/off times...
    Mark
     
  17. Bandit24

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    This is all great info, really appreciate your help Mark

    Can I ask, is a small sized/desk mains powered fan ok? Or do most people use computer fans? How do you power the computer fans? And do you just have the fan turn on whilst the fridge is turned on (ie. double adapter on the temp controller), or do you run it 24/7? I'm assuming 24/7 based on your comment above about the fan creating some heat. No danger to run a shitty little fan continuously like that?

    Couple of other questions regarding my potentially sullied equipment, how far do I need to go?

    - I've got an unused FWK that's been sitting in the same shed for a couple of weeks, since the FWK cube is plastic like a fermenter, if the infection I'm getting that creates Diacetyl can get into plastic easily, is there a chance it could have somehow already infected the unopened FWK?

    - I just bought an o2 kit, and the parts were stored once again in the same shed, in the same plastic tub that holds all of my other brewing equipment (a lot of which has been in contact with infected brews, which I will now be chucking), the o2 kit is yours/Brewman kit, how thoroughly am I going to need to nuke the hose and wand? what about the regulator and stone?

    - What about post-fermentation stuff like PET bottles, bottle tree?
     
  18. Bandit24

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    Posted 25/7/18
    Taken some readings on these latest batches:


    10L Saison
    WLP590
    Fermented at 22c
    1042 - 1004 (7 days)
    Yeast attentuation range 73-80
    Apparent attentuation 90
    Taste doesn’t seem as bad as 2 days ago, but is still pretty bad tasting (or at best extremely average) and has absoluetly no saison yeast flavour. Remember that at day 3 this batch tasted fruity and full of saison flavour.

    10L IPA
    WLP007
    Fermented at 18c
    1042 - 1012 (7 days)
    Yeast attentuation range 70-80
    Apparent attenuation 71
    Within attentuation range but tastes bad, full Daicetyl flavour and nothing else really.

    Also looking back on my previous 3 batches now that I know more about yeast and attentuation:

    Pale Lager - Attenuation Range 67-71, Apparent 83
    US Pale Ale - Attenuation Range 72-76, Apparent 83
    UK Pale Ale - Attentuation Range 67-71, Apparent 77

    On those 3 batches with my pitch rate (1 pack per 20L) and hand stirred aeration method, there’s no way I was hitting those numbers without infection right?

    I used the brewers friends ABV calculator to get apparent attenuation.
     
  19. KE VO

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    Posted 25/7/18
     
  20. KE VO

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    Sorry. Trying to work out how to reply.
    Re. Heating. I have found using a reptile heat chord in my fermenting fridge works well as you just run it around the shelves underneath and it heats the air inside without heating the fermenter itself. It has an electronic thermostat which is set at 20°c. The thermometer is at the top. It keeps my top fermenter at around 20°c and the fermenter at the bottom on 18°c. Never fluctuates at all and never had any heating probs.
     

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