Hey y'all,
I've got an interesting problem. I work in a place that makes a unique product. We do kombucha based beer, I was hired in to help get some QC issues under control, primarily we're dealing with DMS and Diacetyl. To give an idea of our process we mix strong kombucha culture with RO water, add a bunch of sugar, hops, other ingredients, and yeast. We don't and have no ability to boil, and everything is in open top fermenters or old barrels, so I have my work cut out for me. I've introduced as many quality controls for sanitation as I can, but the fact is that we are still in open top fermenters (with cloth over the top), so I can only control so much exposure. Apparently these off flavors are a more recent development, so it hasn't been an issue for the several years they've been in business. We stir in cane sugar up to about 13 Plato, we start at about 3.8 pH with the water/culture mixture, we soak all fresh ingredients in 185F water, otherwise ingredients are frozen. We aren't oxygenating but will soon. We've been using a mix of wine and british ale yeast, I'm looking to cut out the ale yeast to see if the diacetyl leaves, but I still have DMS presenting. Are there specific bacteria I can be looking for that would be producing the DMS? We've been sending out our cultures from bad batches for testing and so far are coming back negative for most spoilage organisms. The kombucha itself is fine and doesn't present any off flavors, so I'm worried its something in the air, or some of the ingredients.
Kombucha is made with a pretty complex symbiosis of organisms, so I'd like to try and narrow down the ones that might be giving us a problem, and our reports have come back negative for a lot of pedio and lacto strains that may cause problems. The DMS is what is the most confusing.
Side note: I'll pull a sample from the tank and run a diacetyl test with no issues, but after transferring diacetyl and DMS will be super obvious. I've never known those off flavors to stratify in the tank. Temperature runs pretty consistently throughout the tank between 68-73F depending on where it is in the brewery.
If anyone has any ideas, I'd be much obliged. Thanks!
I've got an interesting problem. I work in a place that makes a unique product. We do kombucha based beer, I was hired in to help get some QC issues under control, primarily we're dealing with DMS and Diacetyl. To give an idea of our process we mix strong kombucha culture with RO water, add a bunch of sugar, hops, other ingredients, and yeast. We don't and have no ability to boil, and everything is in open top fermenters or old barrels, so I have my work cut out for me. I've introduced as many quality controls for sanitation as I can, but the fact is that we are still in open top fermenters (with cloth over the top), so I can only control so much exposure. Apparently these off flavors are a more recent development, so it hasn't been an issue for the several years they've been in business. We stir in cane sugar up to about 13 Plato, we start at about 3.8 pH with the water/culture mixture, we soak all fresh ingredients in 185F water, otherwise ingredients are frozen. We aren't oxygenating but will soon. We've been using a mix of wine and british ale yeast, I'm looking to cut out the ale yeast to see if the diacetyl leaves, but I still have DMS presenting. Are there specific bacteria I can be looking for that would be producing the DMS? We've been sending out our cultures from bad batches for testing and so far are coming back negative for most spoilage organisms. The kombucha itself is fine and doesn't present any off flavors, so I'm worried its something in the air, or some of the ingredients.
Kombucha is made with a pretty complex symbiosis of organisms, so I'd like to try and narrow down the ones that might be giving us a problem, and our reports have come back negative for a lot of pedio and lacto strains that may cause problems. The DMS is what is the most confusing.
Side note: I'll pull a sample from the tank and run a diacetyl test with no issues, but after transferring diacetyl and DMS will be super obvious. I've never known those off flavors to stratify in the tank. Temperature runs pretty consistently throughout the tank between 68-73F depending on where it is in the brewery.
If anyone has any ideas, I'd be much obliged. Thanks!
Comment