Now that I have a microscope I look at my yeast and beer samples quite often and I’m shocked at the amount of non yeast bugs that I’m seeing . Occasionally I see rods (likely lacto bacillus) and just yesterday I found a surprisingly high number of larger bacteria in my Doppelbock. Those have irregular shapes, are about twice the size of yeast and I was able to make out the flagellum (tail or tentacle like protrusion). Kinda scary to see that in my beer.
But before the microscope I didn’t even know that they were there. The beers don’t taste infected and the pH is around 4.4 which is typical. So I’m not freaking out about this but I used to consider my sanitation processes top notch. For now I’m going to pay closer attention to when non yeast bugs starts to appear in samples. I also started doing wort stability tests again and when I looked at the assortment of bugs in them it was almost all. hardly any rods or other contaminants.
I have to find a low cost way of taking pictures with the microscope to share them. Does anyone know of a good on-line or other source for identifying beer and wort spoilers by looking at them?
Attaching a camera to your microscope can be tricky and expensive. There are a few “cheapies” like the motic 352 eyepiece camera, but it still costs more than $200 (you might google search eyepiece camera or look for low cost telescope cameras). When I worked in the biology department, we created a tube that attached a sony camera to the eyepiece of a stereomicroscope. You set the camera for macro mode, focused through the tube on the eyepiece, and had a fairly cheap method of photographing through the eyepiece. You might also get an eyeclops from the toy store and see if it can work as a sort of capture device.
I’ll play around with that and don’t plan to drop $200 for attaching my SLR. It would be a bit tricky anyway since I only have a monocular eye piece that would not be able to hold the heavy camera.
In the meantime I did some searching. This is a nice article: http://brewingtechniques.com/library/backissues/issue2.5/allen.html that even explains Gram’s staining fairly well. I was hoping that it would be as simple as methylene blue but the stains that are involved aren’t that expensive and I can get them at Cynmar.
I don’t think what you’re seeing are bacteria. They would most likely be large yeast cells or even hyphae (edit:pseudohyphae). Its really hard to tell though without pictures. I don’t know of any bacteria that are larger than even small yeast cells.
I’m just using methylene blue which doesn’t seem to affect bacteria and that other thing. The magnification is 400x and by comparing it to the counting chamber grid I think it is about 2-5 um long.
One of the fungi books we have here say that saccharomyces are 3-9um x 5-20um. The bacteria you are seeing…are they really hard to see? It think would be difficult to pick out bacteria at 400x, especially if its not stained (gram stain).
I’m fascinated too! and Kai, I hope you doing think I’m being difficult. I want to know what’s in your beer too!
Are you putting a drop on a flat slide with a coverslip? Do you have any of the slides with the concave center. It’s pretty cool to watch stuff in those too because you can see free movement.
I can try plating it and should do that. The sample that I looked at contained about 5% of these things with the rest of the population being yeast cells. I’m looking at this in a hemacytometer which means it would be able to move freely.
One possible source might be the picknic tap that I used to pull the sample. I’ll have to check on that too.
On the bright side, the yeast in the Doppelbock was 75% viable and still 0.5 Plato away from the attenuation limit. I still have hopes that it will ferment further.
