nabs478
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Gday guys,
I have been brewing for about 2 years. I would regard myself as a fairly competent brewer and I feel I understand a lot of the stuff going on fairly well, which in part could be due to a background in chemistry. This problem I have, however, has me completely stumped!!
About 6 months ago, I brewed a batch of ESB and it turned out with an off flavour in it that was kind of bitter (not pleasingly bitter, like hops though) and reminded me of the smell in a barn yard where animals have slept (otherwise I could taste a reasonable beer trying to shine through the flavour that has become known among my friends as the barnyard).
Since then I have brewed about 15 batches with one successful witbier and one successful larger. Each time I have spent heaps of time and effort on cleaning and sterilizing and removing different steps of the process to try and work out which step is causing the infection. I was originally running an all grain system with a chilling circuit using counter flow heat exchangers with oxygen injection and a 200L stainless conical fermenter. I have got to the point now where I built a new kettle that holds about 50L (I run a system capable of making abount 160L in a batch), and piped 50L into it while it is boiling from my large kettle, then no-chilled it and transferred it into a plastic 60L fermenter that was thoroughly cleaned and then sterlised with a spray of metho/water mix then 2-3L of boiling water (I also boiled the tap). The barnyard taste was evident 24 hours after pitching the yeast very confusing.
Before I go on further I should describe some of the characteristics of the flavor I get. On about 3 or 4 brews, I tipped them before fermentation was complete because the taste was so strong. In others the flavour hasnt been so bad, in fact I served one that only had it mildly at a party after a couple of kegs of other stuff and it went down ok. I have noticed though in a couple of brews with varying degrees of the flavour that I didnt tip out for a while (up to 8 weeks on one occasion) that the flavor dropped off to some degree over time. One of these I am thinking is nearly drinkable at the moment, and seeing as I cant brew anything that tastes good, I am thinking of taking a keg of it to Meredith music festival in a couple of weeks. I also notice that the off flavor is also more noticeable if the sample is taken from the bottom of the fermenter near the yeast and other crap (sometimes including a little hop debris) than if the sample is taken from the top of the fermenter.
Today I attempted another witbier and had a bit of a revelation. During the boil, a couple of times I thought I could smell the taste I am talking about. I should add here that I have been doing my head in over this problem for a long time, and on one occasion I have thought I could taste it when a brewing friend said they couldnt taste anything, so I could have been mistaken when I smelled that smell. Then after I finished, I had a jug of wort that I tested the gravity from and tasted it. I am sure I could taste it in that sample, which was about 3 hours after it had been chilled.
Like other bitter flavours, it seems to be much more evident once the brew has fermented. I originally thought this was because it was an infection and it needed to actually do some fermenting to leave its flavour behind. Now I think it may be because all bitterness is just more evident when there is less sugar around to balance it. I am thinking now that this could be a problem not caused by a living microorganism, but rather some other crap that is getting into the beer that does not actually change much during fermentation, but just becomes more evident due to the removal of the sugar.
Given this though, I will need to describe my brewing system and cleaning steps. I will start with how I did it originally, then go through the different cleaning and process regimes I have tried.
I have a 3 tank system, HLT, Mash Tun (MT) and Kettle (K). The HLT is a stainless 44 gallon drum with 2x 4.8kW elements, temp control, sight guage and the exit has a ball valve and a solenoid valve in line. The MT is about 100L stainless tank with a false bottom, under which it is a conical shape. On its exit at the bottom of the cone there is a ball valve and a solenoid valve also. The K is basically the same as the HLT, but insulated a little better, has a different type of sight guage and has another exit in the middle on the bottom.
I heat up water in the HLT, transfer it to the MT through the exit in the bottom of th eHLT and into the bottom of the MT. As the water rises from the bottom in the MT, I scoop the grain in and wet it all up. I then leave it for 75mins will more water is heating in the HLT. I then circulate the wort for 15mins by gravity feeding it into a small esky which has level switches installed in it. The level switches drive a pump when it fills up (also shuts the solenoid valve if it gets full and does not empty soon enough) and pumps the water back to the top of th eMT. After 15mins, I start adding water to the MT and pumping the wort to the K (the MT also has a level switch which controls water in flow from the HLT). I then boil it for 60 or 90 mins depending on the beer, add hops, yeast nutrient, whirlfloc and sometimes some spices. During the boil I fill the fermenter I am going to use with some peroxytane (no rinse sanitiser) and pump it through the heat exchangers, oxygen injecting and back to the fermenter for about 15 mins. I let the boil sit to settle for 30mins, then I pump the wort through the cooling circuit into the fermenter (before the beer goes into the fermenter I tip out the peroxytane). Once the flow of hot wort has heated up the heat exchangers I would then turn the tap on for the counter flow to cool it down, and then turn on the oxygen once the flow was cold and it had cooled the liquid in the fermenter to below 30C (this sometimes meant I put 1o-15L through before I turned on the oxygen. All fluid transfer is done in silicon hose or stainless steel pipes with tri-clover clamps to connect them.
Cleaning up originally consisted of the following
- Cleaning out all the grain from the MT and rinsing it with cold water.
- Cleaning out all the hop crap out of the K and giving it a quick once over with a scourer and rinsing it. Also flushing the inlets/outlets and the sight guage
- Flushing the heat exchanger with mains pressure in both directions.
- Rinsing out the esky and all transfer lines with mains pressure.
- Emptying any left over water from the HLT
- Also before using most pieces foir the next brew I would rinse them again and soak them in fresh peroxytane of spray them with a metho/water mix.
I now realise that this is not a very comprehensive cleaning regime and I have done the following during the last 6 months to try to rectify the situation
- The stainless fermenter had some bad welds on in the inside, so before using it I ran a heat gun over the internal welds. I also later tried cleaning it using a spray ball and 50C C4 solution (which is about 2% caustic soda with surfactants and sequesters, and is designed for cleaning stainless food production equipment) and using heat on the welds. When this didnt work, I changed to 60L plastic fermenters.
- I tried pumping 50C C4 through the cooling circuit (cooling circuit comprises of the heat exchangers, pump and oxygen injection assembly) to dissolve any crap, which didnt help. Then I started soaking the circuit in Napisan for at least 24 hours (sometimes much longer like a week or more), then rinsing it again and then soaking it is Iodophor, which I diluted to about 1:100, which is ten times strong than the recommend until the next brew day. Before use I would give it a few flushes with mains pressure and once pumped 15L of boiling water through it, which didnt help. I have now started pumping hot wort through it for 5-10 mins during the boil and back into the kettle, then when I am ready to chill, pulling of the hose going back into the kettle and plugging it into the fermenter. Still had the same problem.
- I have changed the fitting on the oxygen bottle so that it is now an in-post off a corny keg, and sprayed heaps of metho into the reg to sterilize it. I then also boiled the oxygen injection stone, hose and push connect before screwing it into the assembly fora brew. Did not help!
- Pulled apart the 3-piece ball valves on the K and clean and sterilise them.
- As I have said earlier, I have tried boiling it in my K then transferring it to a new kettle (new, as in never used before, and built for this specific purpose) to chill in, then transferred into a fermenter without oxygen injection. I just poured it from a height into the fermenter to dissolve oxygen. I did that transfer in the kitchen which should be far enough away from my garage and any bacteria that has infected other brews. Still no good!
- Next I am thinking of not even using the big K or the esky, and just doing a 50L batch and putting it straight into the little kettle from the MT and then no-chill and into the fermenter.
I have not tried going to town on cleaning the system before the boil as I have ready in a brewing text that visually clean is enough for things that come into contact with the wort before the boil.
It has got to the point where I do not think I am going to brew anymore until I have either got some good advice or read something relevant that explains the problem I am having. I am throwing out huge amounts of beer and no longer have any ideas what could be causing it. I am planning to have a few of my beers tested for bacteria to find out definitively whether it is bacteria or not.
I will try to get some photos of my brewery up tomorrow arvo so people can see whatis going on with it.
I am interested in any suggestions, ideas or similar experiences from anybody that might help my situation!
Thanks
Pip
I have been brewing for about 2 years. I would regard myself as a fairly competent brewer and I feel I understand a lot of the stuff going on fairly well, which in part could be due to a background in chemistry. This problem I have, however, has me completely stumped!!
About 6 months ago, I brewed a batch of ESB and it turned out with an off flavour in it that was kind of bitter (not pleasingly bitter, like hops though) and reminded me of the smell in a barn yard where animals have slept (otherwise I could taste a reasonable beer trying to shine through the flavour that has become known among my friends as the barnyard).
Since then I have brewed about 15 batches with one successful witbier and one successful larger. Each time I have spent heaps of time and effort on cleaning and sterilizing and removing different steps of the process to try and work out which step is causing the infection. I was originally running an all grain system with a chilling circuit using counter flow heat exchangers with oxygen injection and a 200L stainless conical fermenter. I have got to the point now where I built a new kettle that holds about 50L (I run a system capable of making abount 160L in a batch), and piped 50L into it while it is boiling from my large kettle, then no-chilled it and transferred it into a plastic 60L fermenter that was thoroughly cleaned and then sterlised with a spray of metho/water mix then 2-3L of boiling water (I also boiled the tap). The barnyard taste was evident 24 hours after pitching the yeast very confusing.
Before I go on further I should describe some of the characteristics of the flavor I get. On about 3 or 4 brews, I tipped them before fermentation was complete because the taste was so strong. In others the flavour hasnt been so bad, in fact I served one that only had it mildly at a party after a couple of kegs of other stuff and it went down ok. I have noticed though in a couple of brews with varying degrees of the flavour that I didnt tip out for a while (up to 8 weeks on one occasion) that the flavor dropped off to some degree over time. One of these I am thinking is nearly drinkable at the moment, and seeing as I cant brew anything that tastes good, I am thinking of taking a keg of it to Meredith music festival in a couple of weeks. I also notice that the off flavor is also more noticeable if the sample is taken from the bottom of the fermenter near the yeast and other crap (sometimes including a little hop debris) than if the sample is taken from the top of the fermenter.
Today I attempted another witbier and had a bit of a revelation. During the boil, a couple of times I thought I could smell the taste I am talking about. I should add here that I have been doing my head in over this problem for a long time, and on one occasion I have thought I could taste it when a brewing friend said they couldnt taste anything, so I could have been mistaken when I smelled that smell. Then after I finished, I had a jug of wort that I tested the gravity from and tasted it. I am sure I could taste it in that sample, which was about 3 hours after it had been chilled.
Like other bitter flavours, it seems to be much more evident once the brew has fermented. I originally thought this was because it was an infection and it needed to actually do some fermenting to leave its flavour behind. Now I think it may be because all bitterness is just more evident when there is less sugar around to balance it. I am thinking now that this could be a problem not caused by a living microorganism, but rather some other crap that is getting into the beer that does not actually change much during fermentation, but just becomes more evident due to the removal of the sugar.
Given this though, I will need to describe my brewing system and cleaning steps. I will start with how I did it originally, then go through the different cleaning and process regimes I have tried.
I have a 3 tank system, HLT, Mash Tun (MT) and Kettle (K). The HLT is a stainless 44 gallon drum with 2x 4.8kW elements, temp control, sight guage and the exit has a ball valve and a solenoid valve in line. The MT is about 100L stainless tank with a false bottom, under which it is a conical shape. On its exit at the bottom of the cone there is a ball valve and a solenoid valve also. The K is basically the same as the HLT, but insulated a little better, has a different type of sight guage and has another exit in the middle on the bottom.
I heat up water in the HLT, transfer it to the MT through the exit in the bottom of th eHLT and into the bottom of the MT. As the water rises from the bottom in the MT, I scoop the grain in and wet it all up. I then leave it for 75mins will more water is heating in the HLT. I then circulate the wort for 15mins by gravity feeding it into a small esky which has level switches installed in it. The level switches drive a pump when it fills up (also shuts the solenoid valve if it gets full and does not empty soon enough) and pumps the water back to the top of th eMT. After 15mins, I start adding water to the MT and pumping the wort to the K (the MT also has a level switch which controls water in flow from the HLT). I then boil it for 60 or 90 mins depending on the beer, add hops, yeast nutrient, whirlfloc and sometimes some spices. During the boil I fill the fermenter I am going to use with some peroxytane (no rinse sanitiser) and pump it through the heat exchangers, oxygen injecting and back to the fermenter for about 15 mins. I let the boil sit to settle for 30mins, then I pump the wort through the cooling circuit into the fermenter (before the beer goes into the fermenter I tip out the peroxytane). Once the flow of hot wort has heated up the heat exchangers I would then turn the tap on for the counter flow to cool it down, and then turn on the oxygen once the flow was cold and it had cooled the liquid in the fermenter to below 30C (this sometimes meant I put 1o-15L through before I turned on the oxygen. All fluid transfer is done in silicon hose or stainless steel pipes with tri-clover clamps to connect them.
Cleaning up originally consisted of the following
- Cleaning out all the grain from the MT and rinsing it with cold water.
- Cleaning out all the hop crap out of the K and giving it a quick once over with a scourer and rinsing it. Also flushing the inlets/outlets and the sight guage
- Flushing the heat exchanger with mains pressure in both directions.
- Rinsing out the esky and all transfer lines with mains pressure.
- Emptying any left over water from the HLT
- Also before using most pieces foir the next brew I would rinse them again and soak them in fresh peroxytane of spray them with a metho/water mix.
I now realise that this is not a very comprehensive cleaning regime and I have done the following during the last 6 months to try to rectify the situation
- The stainless fermenter had some bad welds on in the inside, so before using it I ran a heat gun over the internal welds. I also later tried cleaning it using a spray ball and 50C C4 solution (which is about 2% caustic soda with surfactants and sequesters, and is designed for cleaning stainless food production equipment) and using heat on the welds. When this didnt work, I changed to 60L plastic fermenters.
- I tried pumping 50C C4 through the cooling circuit (cooling circuit comprises of the heat exchangers, pump and oxygen injection assembly) to dissolve any crap, which didnt help. Then I started soaking the circuit in Napisan for at least 24 hours (sometimes much longer like a week or more), then rinsing it again and then soaking it is Iodophor, which I diluted to about 1:100, which is ten times strong than the recommend until the next brew day. Before use I would give it a few flushes with mains pressure and once pumped 15L of boiling water through it, which didnt help. I have now started pumping hot wort through it for 5-10 mins during the boil and back into the kettle, then when I am ready to chill, pulling of the hose going back into the kettle and plugging it into the fermenter. Still had the same problem.
- I have changed the fitting on the oxygen bottle so that it is now an in-post off a corny keg, and sprayed heaps of metho into the reg to sterilize it. I then also boiled the oxygen injection stone, hose and push connect before screwing it into the assembly fora brew. Did not help!
- Pulled apart the 3-piece ball valves on the K and clean and sterilise them.
- As I have said earlier, I have tried boiling it in my K then transferring it to a new kettle (new, as in never used before, and built for this specific purpose) to chill in, then transferred into a fermenter without oxygen injection. I just poured it from a height into the fermenter to dissolve oxygen. I did that transfer in the kitchen which should be far enough away from my garage and any bacteria that has infected other brews. Still no good!
- Next I am thinking of not even using the big K or the esky, and just doing a 50L batch and putting it straight into the little kettle from the MT and then no-chill and into the fermenter.
I have not tried going to town on cleaning the system before the boil as I have ready in a brewing text that visually clean is enough for things that come into contact with the wort before the boil.
It has got to the point where I do not think I am going to brew anymore until I have either got some good advice or read something relevant that explains the problem I am having. I am throwing out huge amounts of beer and no longer have any ideas what could be causing it. I am planning to have a few of my beers tested for bacteria to find out definitively whether it is bacteria or not.
I will try to get some photos of my brewery up tomorrow arvo so people can see whatis going on with it.
I am interested in any suggestions, ideas or similar experiences from anybody that might help my situation!
Thanks
Pip
