Microwave Confit and Botulism

I hear all the time that we, as home cooks, should not make garlic oils and garlic confit for fears of botulism and that acidification in the home is difficult to do properly. Could you @chris or @grant et al, elaborate on the safety/precautions we should be taking. I notice that on the recipe page for the garlic/onion confit you say it can be stored for weeks which is pretty much the opposite of what I've read over the years.

Love the use of the nuker BTW, it's something that just sits in the kitchen so it'll be happy to have some use.

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Manfred_18311

It would be

certainly of interest to hear what Team Chefsteps know on the theme, I can, by

my own experience and research over the time with jarred food (most fish/

vegetable) contribute to the subject so far as:

Clostridium

Botulinum was historically mostly found in meat/ sausage Botulus = Latin for sausage.

C. Botulinum

is not to mistake with the classifications of the different types and toxicity

of C.B. Which is A, B, C₁, C,₂, D, E, F,

G and H.

C. Botulinum

is killed by:

1. Up and foremost

it personal kitchen hygienic standard! Botulinum is alos to be found in plain

soil, what indicate good cleaning of vegetable, should be simply a standard.

2. Temperatures

above 85° C/ 185° F

3. Low PH

value, < 4.5, most canned or jar preserved fish contaminated by C. botulinum

is caused of the low vinegar content (PH-value >4.5) or low heat.

4. For

vegetable including garlic its low acid valuse account for the occurrence of C.

botulinum

Personally I

always add citric acid to vegetables and fish during the curing period when

supposed to be jarred and stored in jars for a prolonged time at 4° -5° C . Basically

that is exactly what the food industry use (acid additives) to kill C. Botulinum

in first place.

In general serious

Botulinum poison has become very rare; the German health department reported 4 cases

in 2010 on an 85mil population, 2 cases by contaminated beef meat and two by

ingestion of time expired industrial canned food.

You can

detect the development of Botulinum by the occurrence of gas bubbles or a

positive pressure while open the can/jar, if so it’s most likely contaminated

with C.B.

Anyways, It

sure would be an interesting subject to look further into the mechanics of electric

waves in relation of a possible destructive nature to bacteria.

Brendan_Lee_56950

I personally have never had any problem with garlic and herb oils since i make them in small batches and use them quickly but i'm definitely curious about the topic because i'd love to make bigger batches and store them longer.

Manfred_18311

Of course it’s

an interesting subject especially if you going for bigger batches.

The amount

of citric acid used needs to be calculated individually,

From the medical

point of view citric acid contains some interesting values as it indirectly

supports in low added volume calcium build up (bone growth). In excessive amounts

it reacts toxic. Therefore I‘m unable to give any recommendation on the particular

amount added to vegetables or other jarred products.

The LD₅₀ by

rats is 3g/kg.

Assuming to

use 25g c.a. on 2kg of products, what are my usual rate curing different types

of fish and assuming I would eat the 2kg in one sit, my intake ration per kg

living weight would be 0,27g/kg. Adding additional 12% vinegar to the brine

lowers the PH-value to a measured 4.0 which should both, added c.a. acidity and

lowered PH-value, kill any possible C. botulinum.

Adding nitrite

to salt 0.3%-0.4% (I get the salt premixed on this ratio) and using it for curing

or storing could be an alternative as nitrite salt kills C. botulinum just and

is used more often in the meat industry for this matter, and of course for its preservation

properties. Within the EU the use of nitrite (E 250) in industrial sausage production

is imposed by law to prevent any occurrence of C. botulinum

It’s simply

a personal choice to prefer the use of citric acid for its anticoagulant properties

whereas nitrite prevents the hemoglobin to saturate with oxygen in living organism and since almost any meat products cured with nitrite I wellcome to have the choice in my personal use.

DiggingDogFarm_65362

Well, you could store it in the fridge just to be safe and pull it out as needed....the olive oil will re-liquify if it sets at room temperature for a bit.

Here's the chart of times/temps needed to reduce CB by 12D.....

Source: Food Safety: A Practical and Case Study Approach By Richard J. Marshal

Personally, I wouldn't feel comfortable attempting to sterilize in a microwave because they're so notorious for heating unevenly.

nasv

I would also be curious here. I do make garlic oil frequently, but use it or toss it within 5 days or so... same for things I use with the oil (like aioli). More education around this subject is certainly welcome!

Chris_Young_80640

So we goofed up a bit. The intro paragraph said something to the effect that "stored in a cool place the confit will keep for weeks..." What it should have said was, "stored properly refrigerated, the confit will keep for weeks." Microwave heating does not have any special effect on the destruction of C. botulinum spores (at least I've never seen a paper or a technical book that claims otherwise) and, thus, you are simply heating the food, but not hot enough to destroy the botulinum spores.

Submerged in oil, garlic or any other relatively moist food, is under an anaerobic environment; unless the pH of the food is below 4.5 there is a small risk that spores could germinate, begin to grow, and produce botulinum toxin. That's a very bad outcome. To avoid any risk, you should keep the food refrigerated, ideally around 2 °C / 36 °F. At this temperature you are avoiding the risk of spore outgrowth and you can keep the garlic for weeks safely (probably months in fact).

Sorry for the confusion.

Brendan_Lee_56950

No problem. I just wanted to clarify that I wasn't missing something all these years.