Sheldon wrote:

> On Dec 27, 8:55�pm, Reg > wrote:
>
>>Botulism requires a moist substrate to live. Anything dried can
>>be safely used in an oil infusion.
>
>
> That's not true. Botulism survives quite well in dried herbs and will
> begin to multiply in oil as well as water... actually botulism will
> multiply better in oil than in water. Dried herbs won't rehydrate in
> oil so will make good oil bitter. It's best to use fresh herbs to
> flavor oil but to only make up what you will use in say a week or less
> and keep it refrigerated. And keep in mind, dehydrated doesn't mean
> food products contain no water... typically dehy foods contain 10pct
> water by weight... even dry pasta contains about 18pct water.... dried
> herbs contain between 5-20pct water by weight. Bottled salad dressing
> contains dehy herbs, as do many prepared foods, but there is also
> sufficient salt, sugar, and acid to retard botulism growth to safe
> levels, plus many of those food products have been pasteurized.
>

<LOL> That's a whole lot of misinformation in such a small
space.

You seem to be laboring under the misconception that something
must be 100% dry in order to be safe from botulinum growth. That's
incorrect. It just needs to be "dry enough".

Let's put some real world numbers to it, shall we?

The minimum level of water (known as "water activity") required
to support Clostridium botulinum types A and B is 0.93

Dried herbs / dried fruit / dried garlic have a water activity
level well below this. On the order of 0.3 - 0.8.

See:

Evaluation and Definition of Potentially Hazardous Foods
Factors that Influence Microbial Growth
http://www.cfsan.fda.gov/~comm/ift4-3.html

Like the original cite says, dried products are safe to use in
oil infusions because they won't support botulinum growth.

And Sheldon is FOS as usual.

--
Reg