Anything I’m Fermenting

May 15, 2008

Yogurt making

Filed under: Lactobacillus,Pictures,Yogurt — iwouldntlivethere @ 3:34 pm
Tags: , , ,

Well, after this post on my home made yogurt, I’m running out of fermentables to write up, I think only bread remains undocumented. Yogurt making is actually one of the primary reasons I started this blog, as it was Jen B.’s interest in it that prompted all this. However, I only make yogurt once a month at most so it has taken a while to be able to take pictures of the process (and on the day I made it one camera was out of power, and the other with my wife, so I had to use an actual film camera with a few pictures left, then get them developed – can you notice difference? The last 3 pictures were taken with a digital camera) . I usually make five tubs of 750 ml in each batch, which lasts us for over a month often.

This longevity is, I believe, the original reason for making yogurt – as a way to preserve dairy products. Only one batch (when I discovered that my electronic thermometer gives funny readings when immersed in water for long periods) had issues – a bit of mold growth on the sides of the last tub when I opened it (but the yogurt itself was OK – at least, nothing happened to me after eating it). The reason for the mold was that because my thermometer was not working properly, I was not holding the yogurt at high enough temperatures, so it did not acidify enough, which in turn made it more susceptible to mold infections – but only marginally so.

So, the theory behind yogurt is to ferment milk using a lactobacillus/thermobacillus culture to acidify it to help preserve it, and (a bit less clear on this part) to make it more easily digestible by adult humans. Initially the milk should be scalded – briefly brought up to at least 95 degrees . From what I understand, this is to modify the milk protein (makes the yogurt thicker and taste better), and probably kills off most competing bacteria. To properly and quickly ferment, the milk must then be held at temperatures between 40 and 50 degrees for several hours.

In practice, this is how I do it:

Create a free website or blog at