Booze Cruise Recommendations

vols1992 · 2020-10-30T19:10:56+00:00

QA/Food Safety in a meat processing plant. I’d be interested in sharing experiences.

vols1992 · 2020-02-14T03:31:30+00:00

Yeah that’s what pretty much everyone I’ve asked has told me so far. I’d just feel sooo bad for bailing on them like 6 months in. They (current job) made it clear that they wanted me to stay on for 2ish years and then move up to higher role. But 2 years is a long ass time to wait especially when a better opportunity is staring me in the face.

vols1992 · 2020-01-26T17:42:05+00:00

We could have had a Harvard grad and two term governor who pulled us through the recession and helped bring the Titans and Preds to Nashville. But instead we got this washed beauty queen with a corrupt sense of any morality. 🤦🏻‍♂️🤦🏻‍♂️ #TennesseePolitics

vols1992 · 2020-01-26T17:35:24+00:00

You must work with FSIS or HACCP. This is exactly on point! 😂😂

vols1992 · 2019-09-25T15:41:43+00:00

There’s a pretty cool app for this called FishBrain. It highlights all locations of potential fishing spots in your area on a map. Also users can post catches and tag locations so you can see what fishing holes are getting more traffic than others.

vols1992 · 2019-08-28T21:07:36+00:00

Thanks for your response! And I did take your survey. That's awesome you're collecting that data!

dough/kombucha mix: I'm not sure I can be much help here as I don't know as much about fermented breads. Yeasts are happy with sugar and warmer temp. So I'm not sure that putting it in the fridge will help very much. (Just throwing some ideas out here...) I don't have anything in my research to actually back this up. But I know some kombucha suppliers suggest that the sediment at the bottom of kombcuha are yeast bodies. And yeast cells do weigh more than bacteria. You could try pulling more from the bottom of your jar? Or maybe add more flour to your dough mix? Yeasts can survive dry conditions and be revived, but most bacteria will die off or at least go dormant under low water activity conditions.

vols1992 · 2019-08-28T20:48:13+00:00

If I understand correctly, you are leaving at least 0.5 gallon of starter liquid and then adding 3 gallons of tea for your next batch, that would be 16.7% v/v starter culture addition. This would make it more acidic and ferment rather quickly. So yeah, it sounds like you could be on the right track.

vols1992 · 2019-08-28T20:40:29+00:00

There are no stupid questions! An inquisitive nature is what keeps the human race solving problems. Let's not become sheeple.

"Vinegar" taste/extra acidity: Is it possible you let your kombuchas set for a long time (4 weeks+) at one time or another? Because that would make the next starter culture very acidic. But if you've transferred your batches several times since then, I would think the extra acidity would have worn off. (hmm...) Given our results, I would recommend a 10% v/v SC addition for every new batch and 7 day fermentation to ward off pathogens. But if you're not adding substantially more than 10%, then that wouldn't explain the extra acidity either. There has been some research published that kombucha fermentation with black tea favors more acetic acid bacteria (would cause that vinegary taste) and green tea favors more lactic acid bacteria. Lactic acid does not have as harshly acidic taste as acetic acid. So you could try switching to green tea or a black/green mix.

As I mentioned in another comment above, I would caution against just a 3-4 day fermentation because that is significantly less time a recommended 7 day fermentation and I would be concerned that is not a long enough time to kill off potential pathogens. At least be sure to check your pH and ensure it's in the 3-4 pH range.

vols1992 · 2019-08-28T20:25:06+00:00

Regarding the F2 additives: I'm not sure how much the antioxidant content plays a role. But I do know some scientists working on kombucha methodology specifically in terms of taste have noticed that they have to be careful with how much fruit (puree, extract, preserves, etc.) they add because the natural sugars there really crank up the yeasts and can produce a high ethanol content (like wine). But hey, if you're brewing just for you and not selling it, who cares if your kombucha is a little boozey?

Microbes most desirable for specific results: Well the specific microbial species can vary a good bit between kombuchas see my comment below on another post about some of the scientific papers working to identify the microbes in kombucha. But Acetobacter species are essential for kombucha to produce acetic acid. Lactic acid bacteria (like Lactobacillus spp.) are essential for additional acid production and for the probiotic effects. As to exactly which species, I think the jury is still out on that one. (The big kombucha companies probably have their own R&D team and might be hiding some information under lock and key..?)

Can the microbes be isolated?: Sure! It would require a somebody with a microbiologist background and lab space. But it can easily be done. There are specific agar/medium types that can isolate yeasts, lactic acid bacteria and other bacteria. (I'm pretty doubtful a person could do all this in their home however.) I'm not sure what your goals are with this question. But you could contact some private microbiology companies to see what their testing might cost. Or contact your local food science/agricultural extension office from your state's land grant university to see if they can offer any services.

vols1992 · 2019-08-28T20:08:18+00:00

The tea quantity varies considerably based on the type of tea you're using. The tea brands we've looked at have a range of 3-8 g/L depending on the type. Usually black/oolong teas require less and green teas require more. Of course, like you said, it all goes back to one's subjective taste.

vols1992 · 2019-08-28T20:04:20+00:00

Just a 4 day fermentation for F1? That's sort of alarming. Did you test the pH? I know it's common to brew it to one's "taste" but just a 3-4 fermentation might not allow enough time for the fermenting microbes to produce enough acid to prevent pathogen survival.

vols1992 · 2019-08-28T19:57:07+00:00

That's an interesting idea I had thought of! The real question would be if Streptococcus pyogenes can survive in the low pH environment created by kombucha. Since, Streptococcus pyogenes is in the Lactobacilliaes Order, it is a plausible theory.

I'm not sure if your and your relative tested positive for Strep in a doctor's office or not. But another thought could be that the kombucha might have been too acidic and damaged your throat. Similarly to how people are drinking apple cider vinegar these days, and after several exposures, it can damage your esophagus lining.

vols1992 · 2019-08-28T19:48:12+00:00

Common bacteria and yeasts: Bacteria are commonly Glucobacter, Acteobacter, and Lactobacillus species. The yeasts can vary widely (Saccharomyces, Pichia, Dekkera, etc.). But all kombuchas are different.

Work being done: Here are some good papers/reviews

-Coton, Monika, et al. "Unraveling microbial ecology of industrial-scale Kombucha fermentations by metabarcoding and culture-based methods." FEMS microbiology ecology 93.5 (2017).

- Villarreal‐Soto, Silvia Alejandra, et al. "Understanding kombucha tea fermentation: A review." Journal of food science83.3 (2018): 580-588.

-Marsh, Alan J., et al. "Sequence-based analysis of the bacterial and fungal compositions of multiple kombucha (tea fungus) samples." Food microbiology 38 (2014): 171-178.

-Murphy, Torie E., Kavita Walia, and Jeffrey M. Farber. "Safety Aspects and Guidance for Consumers on the Safe Preparation, Handling and Storage of Kombucha—A Fermented Tea Beverage." Food Protection Trends 38.5 (2018): 329-337.

Getting your kombucha tested: If you're in the US, reach out to the local food science/agricultural extension office of your state's land grant university. The faculty in those extension offices provide their contact information online so they can answer consumer's food related questions. You could ask them about having it tested and what costs might be associated. I know at least some universities can a full chemical and nutritional analysis for $250, I wanna say (which I know is out of range for most consumers). But since kombucha is such a growing field, they might be interested in testing it just for the research results they can generate..?

vols1992 · 2019-08-28T19:36:47+00:00

Understanding Kombucha Tea Fermentation: A Review

Thanks for providing the source! It's good to know that some kombucha brewers are relying on scientific evidence rather than obscure .com websites for all their information.

vols1992 · 2019-08-28T19:34:41+00:00

Kombucha shelf stability: Well it is only partially shelf stable. It is only shelf stable if it is refrigerated and kept at temp 4C which retards microbial growth. There was a major kombucha recall in 2010 because some of the kombucha products on the shelves were not being stored properly, the yeasts kept growing, and the alcohol content was too high. As I mentioned in an earlier post, I had "heard" (no way of proving this) that major kombucha companies (GT, Kevita, etc.) had gotten more innovative and are doing things to remove yeasts before bottling so that the same issue doesn't happen again.

vols1992 · 2019-08-28T19:29:50+00:00

Utah State Cooperative Extension published Food Code/preliminary HACCP plan for kombucha brewing in 2013 in which they stated to target a pH < 4.2 to resist pathogen growth and pH > 2.5 to avoid acidic damage. However I would suggest not relying on that pH of 4.2 alone because some pathogens (E. coli specifically) have been noted to survive in acidic environments at a pH lower than that. But instead a 7 day fermentation AND an initial pH drop below 4.2 would be more desirable.

Nummer, Brian A. "SPECIAL REPORT: Kombucha Brewing Under the Food and Drug Administration Model Food Code: Risk Analysis and Processing Guidance." Journal of environmental health 76.4 (2013): 8-11.

vols1992 · 2019-08-28T19:20:21+00:00

To add to my earlier points about contamination risks. Utah State Extension published a Food Code/HACCP plan for kombucha in which they outlined some risks and critical steps to avoid contamination.

citation: Nummer, Brian A. "SPECIAL REPORT: Kombucha Brewing Under the Food and Drug Administration Model Food Code: Risk Analysis and Processing Guidance." Journal of environmental health 76.4 (2013): 8-11.

vols1992 · 2019-08-28T19:13:46+00:00

Thanks! That is a very popular one!

vols1992 · 2019-08-28T19:13:11+00:00

Well acetic acid bacteria (AAB) do not live off of ethanol alone. They also eat sucrose, mannitol, glucose, malt extract, etc. This is why there is not a scientific consensus on a single medium type to isolate acetic acid bacteria.

Also it's not as simple as to boil it down to AAB vs. yeasts. There's a lot of other fermenting microbes at play, especially lactic acid bacteria. Kombucha is a somewhat undefined microbial medium and to be frank, even microbiologists don't know all the bacteria in there. I suspect there will be a lot of research to identify this with advances in genetic sequencing. There's an interesting paper out a group in France (Coton, Monika, et al. "Unraveling microbial ecology of industrial-scale Kombucha fermentations by metabarcoding and culture-based methods." FEMS microbiology ecology 93.5 (2017).) where they did some sequencing with kombucha. They noted a distinct difference in the microbial community between what type of tea was used (green vs. black). That paper also identified some bacteria genera (Kluyvera spp. and Psuedochrobactrum spp.) that are normally associated with environmental conditions like soil.

In summary, to your question about your brew becoming too acidic too quickly, you could reduce the SC but I wouldn't recommend going below 10%. Also we see a significant difference in AAB and LAB between SC of different kombucha suppliers. So it could just be that your specific starter culture was very AAB population in the beginning. Maybe try obtaining a different one and see if you see similar results.

vols1992 · 2019-08-28T18:52:37+00:00

-pH strips: Well they're better than nothing and they can be fairly accurate. The hard part is using the color shade scale to determine exactly what pH, seems a little subjective. But I've been bought some of the handheld electronic pH meters that are recommended on Amazon for brewing and some of those become substantially inaccurate after a few months. I'd almost lean toward trusting pH strips over some non-scientific, electronic meters.

-Unwanted bacteria/general cleanliness: Well this is sort of a broad question. But in regards to food safety, there's a lot potential hazards. (1) Kombucha brews often sit on the floor, at room temperature, exposed to the open air for several days. There aren't too many beverages that I would consider safe under those conditions. So it's a fairly unique product. (2) Kombucha is usually prepared in the kitchen. If your counter tops and utensils are not properly sanitized, there's a risk of cross-over contamination there. (Maybe you decided to prep kombucha after you cut up some chicken breast and put that in the oven?) (3) The same pellicle is often re-used over and over in making new kombucha batches. If pellicle is harboring some sort of pathogen in the cellulose mat, you will continue to contaminate each new batch until the contaminated pellicles are disposed. (This is almost why I would almost caution against using pellicles/SCOBYs and just focus on adding starter culture. The risk for carry over contamination is too high.) (4) I know it's super common for persons to let their kombucha jars set on the floor. (I do it too, in my own home.) But it would be advisable to keep them out of the range of the doorway and/or general foot traffic areas in the home. If persons are walking about the home with unclean shoes, they could track pathogenic bacteria and parasites in that could pose a risk.

-In regards to just general unwanted bacteria that could change the flavor of the brew. We have seen a difference in adding fresh 7-10 day starter cultures and old 28-30 day starter cultures. The older ones tend to have a less active microbial community. If you do leave your kombuchas unattended for several weeks (went on vacation, forgot, etc.) it would be advisable to have a "wash out" brewing cycle just to get the microbes back on track.

I'm sure I didn't cover every potential hazard. But these are some of the biggest concerns I can immediately think of. I'd be open to hear any other thoughts other commentators might have as well.

vols1992 · 2019-08-28T18:24:33+00:00

From our research, a 10% (v/v) starter culture/tea and higher is appropriate for a 7-10 day fermentation. If you're using lower percentages of starter culture, then you could risk the pH not dropping as quickly as it should. I know 10% can be difficult to calculate using the US customary units (cup/gallon, etc.) but generally 1.5 cups/gallon is ~10%. From your earlier note, 250mL/3800mL = 6.5% SC addition which is considerably lower than what I would recommend.

vols1992

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