Why You Should Never Use Raw Garlic For Sous Vide Cooking
Sous vide cooking may seem like the ultimate "safe" way to not mess up a meal, but there are some things like raw garlic that defy that reputation. It may seem like an easy way to infuse your steak or vegetables with some garlic flavor, but it's actually best to cook your garlic before tossing it in the bag.
Sous vide's unique style of slow, steady, low-temperature cooking creates conditions that can make raw garlic dangerous to eat, similar to the "temperature danger zone" you may have heard of when using meat or dairy. Leaving food out for extended periods of time between 41 and 135 degrees Fahrenheit can lead to bacteria growth, and in the case of garlic, that bacteria can cause a disease called botulism, per Minnesota Department of Health.
Botulism thrives at room and warm temperatures up to around 125 degrees Fahrenheit. Normally when cooking, your garlic would be fried or roasted to temperatures well above this where the disease causing bacteria would die off, but when using sous vide you are often cooking at low heat in this range. Even if your final target temp is higher, things like steaks can take a long time to come up to temperature, and may spend hours in this "danger zone." The risk can be minimal, but botulism is a serious disease that can cause blurred vision, muscle paralysis, difficulty breathing, and even death (via the CDC). Considering there are other ways to get garlic in your sous vide, it's not worth the risk.
Garlic in sous vide carries a risk of botulism
Botulism is created by the spores of a bacteria known as Clostridium botulinum, according to the World Health Organization. That bacteria is present in most soil, and garlic picks up this bacteria as it grows. It's normally harmless, which is why you don't hear any concerns over garlic in the vast majority of recipes, but in warm and low-oxygen conditions like those present in sous vide, it starts to form the spores that cause botulism. There are a few other ways of cooking garlic, like garlic confit, that also carry these risks. But sous vide has become widely popular, and with the ease of tossing in some raw garlic, the danger may not be obvious.
It also doesn't help that sous vide garlic doesn't taste that great, so even if there is a small risk of disease, you're doing it for nothing. The low temperatures of sous vide doesn't brown the garlic and develop its flavor and doesn't cook it enough to get rid of its more unpleasant, bitter tastes. Stick to giving your garlic a nice sauté or roast before adding it in, or just use garlic powder and eliminate all those concerns of botulism while also getting better flavor. There is basically no upside to raw garlic in sous vide, and the downsides are bad enough it's best to just avoid entirely.