Infection probabilities

[IJesusChrist]

I work in a biology lab. I work in a laminar flow hood. If I touch anything with my finger, within 1 week a large plume of bacteria or fungus will take place in my fingerprint.

That said, I always find it odd how we brew beer and say be 'sanitary'. Its impossible to be truly sanitary, for as soon as you expose anything to unsanitized air, thousands of spores and possible bacteria are going to climb in.

I wanted to probe some questions because of this;
If I stuck my finger in a matured beer, 5%, a wine, 12% and a heavy wine at 18%, and capped them, would I expect some infection?

Is there a large amount of bacteria/fungus that can grow in >5% abv?

If I didn't wash my hydrometer on first reading, would I be screwed?

It seems like infections in fermentation are so much more subtle and rare compared to infections in a lab setting on agar...

Do you think a newb like me would benefit from wearing latex or nitrile gloves during brewing and dipping them in sanitizer?

Do you all sanitize on every hydrometer reading?

Basically - how tight should I be with sanitation? Is there such a thing as overboard?

 

[crispbrew]

You are over thinking it, I work in a micro lab also so I was paranoid about sanitation when I started. Just sanitize everything that comes into contact with the wort post biol and limit air contact as much as possible.

wort/beer for whatever reason does not facilitate the growth of many bacterium, I have not looked into the literature for why that is so. Also if you pitch the yeast correctly where they can begin fermentation quickly they pretty much will out compete any foreign organisms that may be present in the wort.

There was a thread on here where someone pitched yeast that they scraped off the floor and had no infection. Though that was probably a lucky instant it shows how you don't need to use bio lab level of standards when sanitizing.

 

[fatbloke]

Definitely a weird subject.........

I appreciate the difference between laboratory type hygiene and what we tend to do. With beer and wine making it seems its more about being anti-fungal so its only the innoculated yeast that does its thing for its given/known alcohol and flavour characteristics. Basic hygiene techniques would generally prevent most bacterial problems that's not to say they don't exist they just don't seem to usually be a problem........

Equally I understand that the preservation effect of alcohol works from above 10%, but could also explain some of why beer making is more hygiene focused.

Where the possibilities of oxidation come in, is different again and also seems to be linked to alcohol content........

Definitely worth reading up some more, not to be paranoid just to understand it more.......

 

[taoisilent]

3 things protect your beer once it gets into the fermenter: a healthy quantity of yeast that will usually out-compete and out-perform other fungus and bacteria, Hops which have well known anti-bacterial properties, and the resulting alcohol which make it more and more difficult for pathogens to take root.

I sanitize the thief I use to take samples for the refractometer or hydrometer because it's so easy to do. I keep a gallon jug of star san on hand at all times. But I only take one post fermentation reading, after several weeks in primary for my notes. Unless you're dying to bottle or keg as soon as possible, it doesn't make sense to take multiple readings. I'm a big advocate of leaving your beer alone to do its thing.

Cheers!

 

[loveofrose]

The low pH of wort/must also limits the amount of organisms that can grow. Including yeast if it goes below 3!


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[bernardsmith]

I have no background in biology or organic chemistry and I make wine not beer but I believe that the yeasts we tend to use - and we add them, typically, in large colonies rather than a few cells at a time - create an environment for themselves that favor their reproduction and inhibit the reproduction of competing bacteria and other infestations. I'm sure that happens with all life forms but again, we inoculate the must (or wort) with a large colony rather than (to use a gardening term) work with volunteers.
I am not OCD (I don't think I am) but I spritz or soak in k-meta any tool that comes into contact with my wines before I use it - hydrometers, thieves, measuring cylinder, hoses, siphons. I assume that the yeast are virile enough to withstand the SO2 and any bacteria on the surface of the tools will be weak enough to give up the ghost...so I am helping the yeast by inhibiting access of competing flora into the wine.

 

[noblesquirrel]

Actually, you can be sanitary. Sterility is what I'm guessing you're talking about.

 

[IJesusChrist]

Actually, you can be sanitary. Sterility is what I'm guessing you're talking about.

Quite true. Sanitary isn't very quantifiable, is it?

 

[fatbloke]

Quite true. Sanitary isn't very quantifiable, is it?

No......

Equally, maybe a better choice of title would have prompted better consideration i.e. possibilty instead of probability.......

There's no guarantee that it will become infected......

 

[IJesusChrist]

I wonder if being totally sterile would be beneficial. I'm sure there is always going to be SOMETHING else growing in your brew, at least the first few days (depending on fermentation rate), that may add some unintended flavors.

This is kinda what I was thinking about when I made this post.