Roasted Garlic: Technique, Equipment

[WHT]

I have a clay pot and tray from the garden store I use. Cost all of $2.00.

[devlin]

I've roasted and stored garlic still in their skins and loosely wrapped in foil for several years now (well, I mean as a method, not that I've actually kept it for years) never giving it much thought. That is until I started reading some cautionary stuff here awhile back.

So as I'm about to bake a couple loaves of bread tomorrow into which I've incorporated a head of roasted garlic that's been sitting in my refrigerator for a week now (stored as noted above), I suddenly wondered whether I might be about to kill my husband and neighbors.

Is this safe? Am I worrying unnecessarily? I've done this many times before with no ill effects. Have I just been playing with fire?

Do I have to throw this batch of dough out?

[Shalmanese]

roasted garlic is fine, it's only raw garlic that can potentially cause botulism. I keep cloves for several weeks with no problems. I like to roast the cloves, mash them up with a bit of butter and put them in squeeze tubes. It's really easy to portion out into whatever dish needs it.

[WolfChef]

roasted garlic is fine, it's only raw garlic that can potentially cause botulism.

←

What? I must have missed this topic...what gives...how can this happen? What's the name of the topic?

[A Patric]

Hi,

Any time non-preserved foods are altered from their natural state there is more of a risk for botulism growth. Mashed up garlic, whether raw or roasted would have botulism potential, though the higher the simple sugar and acid content in an item, the lower the risk. Therefore, roasted garlic should be "safer" than raw that has been mashed up due to its simple sugar increase. Of course, the problem of botulism is exacerbated by leaving food items that are higher risk out at room temperature. So, a mashed up clove of garlic mixed with olive oil at room temperature is a very high risk, while one in the fridge is much less so. Roasted garlic in the fridge would probably be the least risky that one could get aside from clove garlic that has not been altered from its natural state. I would think that one week in the fridge should be fine. But, seeing as how I don't want to be responsible for anyone getting sick, don't just listen to me. Do some reading for yourself and make a decision. Other things to keep in mind are the fact that high heat kills botulism spores and eventually destroys the toxin. I'm not sure what temperature bread reaches, but it may easily destroy any spores and toxin that are formed. You'd have to look this up online. I don't remember everything that I've read over the years.

Alan

[Patrick S]

I've only heard about botulinum growing on garlic when it has been stored in oil, which provdes the anaerobic environment that C. botulinum needs to grow.

Edited February 17, 2006 by Patrick S (log)

[snowangel]

I often roast a whole mess of garlic and freeze it. Just squeeze the cloves out on a parchment lined baking pan, freeze and pop the clumps into a zip lock.

[A Patric]

I've only heard about botulinum growing on garlic when it has been stored in oil, which provdes the anaerobic environment that C. botulinum needs to grow.

←

Yes, good point. I forgot about the whole anaerobic issue. So...

Risky is:

room temperature

low sugar

low acid

low salt

high moisture

anaerobic conditions (such as in oil)*

long storage times until consumption*

*(unless something has been canned properly with the proper temperature for the proper time, and preferentially, under pressure)

Less risky is:

refrigerated (closer to 32 the better) or frozen

high sugar

high acid

high salt

low moisture

access to oxygen

short storage times until consumption

and after looking it up on this site:

http://www.fda.gov/fdac/features/095_bot.html

It seems that the toxin is destroyed with 10 minutes of 212 degree heat, and the spores themselves at 10 minutes of greater than 212 degree heat. From what I have just read, I don't think that internal bread temperatures reach this range, so they might not destroy the toxin or spores.

Anyway, like I said, don't believe me, go look things up online at reputable sites.

Alan

[andiesenji]

I roast large batches of garlic in a significant amount of oil in the oven for a long time at a low medium heat - 250 - 275.

I buy the large containers of peeled garlic at Costco, Sam's Club or Smart & Final, put them in a deep ovenproof vessel, and add oil (regular cooking olive oil is fine, you don't need the fancy or extra-virgin) until the garlic is completely covered plus an inch or so.

I roast it this way (stirring once or twice if I think of it) until the cloves are uniformly brown and nicely carmelized. Use a dry slotted spoon and fish out a couple, let them cool and taste. It should be quite sweet.

Prepare some one pint canning jars by sterilizing them, scald and invert them so they will be completely dry inside. Sterilize the lids too.

While the oil and garlic are still hot, ladle some of the cloves into each jar, fill about 1/3, then fill to the top with the oil, place the lid and tighten the ring.

If you are going to use it up in a short time, you don't even have to jar it this way, just keep it in a sealable container but only use a sterilized and dry utensil to dip into the oil.

Either way, this does not require refrigeration. Canned and sealed, it will keep for at least a year.

On the counter, in a resealable jar (I have one with a wire snap closure and a rubber ring) it will keep fine for three months at least, as long as you don't introduce something to it.

You want the jar to seal so the aroma will not be constantly perfuming the immediate area.

During the oven roasting it will make itself known.

I have been doing this for years and have never had a problem with the garlic going "off" or the oil turning rancid. In fact, I have extended the life of the stuff in the jar on the counter by removing the wire bail, placing the jar without the lid, in the microwave and heating it until it bubbles, following someone putting a scalded ladle that still had some water in it into the oil. Boiling the oil (carefully) in the microwave will drive the water out of the oil.

I use the oil in cooking, in marinades, for dipping bread and etc., and the mashed garlic is also lovely spread on bread, bagles, or just added whole to a recipe. In particular, when I roast mixed root vegetables, I prefer the roasted garlic in oil to raw garlic.

[devlin]

Very fabulous info. Thank you all, and Andiesenji in particular for that lengthy response.

I've roasted garlic for years and kept it refrigerated to use whenever the need arises, especially in salads and pasta and either to incorporate into baked breads or to spread on already-baked bread. It occurred to me also last night that it might be easier to liberate the cloves from the skin before I bake, since squeezing the already-roasted cloves out of the skin en masse is a sticky mess and more time consuming than peeling them raw. And Andiesenji's message pretty much confirms it'll work just as well, it seems to me.

[andiesenji]

I just happen to adore pasta (linguini in particular) with garlic and oil, nothing else but perhaps a little salt.

Having this on hand makes it so simple to cook and drain the pasta then dip a ladle of the roasted garlic and oil onto the pasta and toss, instantly ready to eat.

[devlin]

I just happen to adore pasta (linguini in particular) with garlic and oil, nothing else but perhaps a little salt. 

Having this on hand makes it so simple to cook and drain the pasta then dip a ladle of the roasted garlic and oil onto the pasta and toss, instantly ready to eat.

←

Mmmmmm, yes. I do that but with fresh-grated parmesano as well. I have to warn my husband in advance that it'll be a smelly day ahead, because I use enough garlic to be noticed a few feet in advance I'm sure. It's one of my favorite things in the world, and given a choice between that and a favorite dessert, or ice cream, it's kind of a draw.

[PicnicChef]

Going back to the safety issue. We learned in Serve Safe and Food safety classes in school that you should never keep two things for more than a day

1) roasted garlic

2) carmelized onions...

Both can have botulism if left for a day...

[devlin]

Going back to the safety issue. We learned in Serve Safe and Food safety classes in school that you should never keep two things for more than a day

1) roasted garlic

2) carmelized onions...

Both can have botulism if left for a day...

←

That reminded me that I meant to ask if there was anybody here who'd taken such classes and what the literature there might say.

THAT said, does it make a difference if the roasted garlic is refrigerated immediately?

edited to ask this question: Is there a book on the subject you'd recommend?

Edited February 18, 2006 by devlin (log)

[andiesenji]

Information re: botulism

If the organism is subjected to high enough heat for long enough it will destroy both the oranism and the toxins produced by it.

It grows and produces toxins only in an anerobic enviornment, that is, without air, or rather oxygen.

When cultured in the lab, it has to be stabbed into a test tube containing growth media, it will not grow on media in a petrie dish. (I was a laboratory technician in the Army many years ago and we cultured samples from suspect food items after an outbreak - canned salmon was the culprit, insufficiently processed.)

Low acid foods, green beans are the "classic" example, that are not processed long enough, fish, meat, fowl and even cheese can be a problem.

However, once the food is cooked for long enough at a high enough heat, and stored properly, and nothing new is introduced to contaminate it, botulism doesn't come floating out of the air unless you are living in a barnyard.

If you are concerned, use a thermometer and check to be sure the oil reaches the critical temperature (at least 250 degrees F) and remains at that temperature for sufficient time. Two plus hours is plenty. The last batch I made was in the oven at 275 degrees for three hours.

[Patrick S]

Also I would add that garlic can be stored in oil, provided some acid is added. Garlic normally has a pH of 5.3 to 6.3, but if the pH is made 4.5 or lower, C. botulinum can't grow. This is usually done commercially by adding phosphoric or citric acid. How to do this at home, and how much to add, I couldn't tell you.

[jgm]

I'd like to revive this topic. I have some purchased, peeled garlic sitting in the fridge that has an expiration date near the end of this month. Rather than throw it out when it expires, I'd like to use Andie's method (above) for roasting the garlic.

However, I'd like to freeze it after it's roasted. What would be the best way to do that? I do have a vacuum-sealing machine, if that would be the best way to go.

I'm not very confident in my canning skills, and I know that if I tried Andie's canning method, I'd just get paranoid, and fear that things hadn't been sterile enough, and would never use it for fear of getting sick.

[GlorifiedRice]

Garlic and Onions and their Ilk all have antibiotic properties. RAW More so.

Raw Garlic and Onions et al have a substance called ALLICIN, which kills bacteria.

The more cell walls of the raw clove you crush, the more allicin you release.

It takes a long time for garlic and onions to go rotten because they are so antibacterial.

Chicken Soup got its name of "Jewish Penicillin" due to the head of garlic in it.

[andiesenji]

Freezing is fine, drain the garlic cloves well and blot them dry with paper towels and use a canning funnel to put them into the vacuum bag. If you get any oil at all onto the surface that is going to be fused, the seal will not hold.

Again. Once you have roasted the garlic cloves in the oil so the oil reaches at least 250 degrees Fahrenheit and remains at that temperature for at least 15 minutes, the spores are killed and the toxins are destroyed.

UNLESS you introduce additional raw garlic to the oil, there will be NO spores and NO toxins.

I use one of the thermometers that has a wire cable and the sensor point on the cable is 3/4 to 1 inch from the tip. I make sure this section is deep in the oil.

I set the control to sound when the temperature of the oil reaches 250 degrees.

When I hear the signal, I set the timer for 15 minutes. When that sounds, I know that all of the spores have been killed and any toxins present have been destroyed.

I have been using this method for 40+ years and I use a lot of roasted garlic in oil. Never had a problem. And the only reason to add acid is to keep the spores from producing toxin - acid does not kill the spores - it also turns garlic blue, especially when it is chilled.

The link I attached to one of my earlier posts is very specific.

[jgm]

Thank you, Andie!

Jenny

[heidih]

I roast large batches of garlic in a significant amount of oil in the oven for a long time at a low medium heat - 250 - 275. 

I buy the large containers of peeled garlic at Costco, Sam's Club or Smart & Final, put them in a deep ovenproof vessel, and add oil (regular cooking olive oil is fine, you don't need the fancy or extra-virgin) until the garlic is completely covered plus an inch or so. 

I roast it this way (stirring once or twice if I think of it) until the cloves are uniformly brown and nicely carmelized.  Use a dry slotted spoon and fish out a couple, let them cool and taste.  It should be quite sweet. 

Prepare some one pint canning jars by sterilizing them, scald and invert them so they will be completely dry inside.  Sterilize the lids too.

While the oil and garlic are still hot, ladle some of the cloves into each jar, fill about 1/3, then fill to the top with the oil, place the lid and tighten the ring. 

If you are going to use it up in a short time, you don't even have to jar it this way, just keep it in a sealable container but only use a sterilized and dry utensil to dip into the oil. 

Either way, this does not require refrigeration.  Canned and sealed, it will keep for at least a  year.

On the counter, in a resealable jar (I have one with a wire snap closure and a rubber ring) it will keep fine for three months at least, as long as you don't introduce something to it.

You want the jar to seal so the aroma will not be constantly perfuming the immediate area.

During the oven roasting it will make itself known. 

I have been doing this for years and have never had a problem with the garlic going "off" or the oil turning rancid.  In fact, I have extended the life of the stuff in the jar on the counter by removing the wire bail, placing the jar without the lid, in the microwave and heating it until it bubbles, following someone putting a scalded ladle that still had some water in it into the oil.  Boiling the oil (carefully) in the microwave will drive the water out of the oil. 

I use the oil in cooking, in marinades, for dipping bread and etc., and the mashed garlic is also lovely spread on bread, bagles, or just added whole to a recipe.  In particular, when I roast mixed root vegetables, I prefer the roasted garlic in oil to raw garlic. 

←

I do the same thing with the ready peeled garlic except I only make about 2 jam jars full at a time and I refrigerate it. The oil solidifies somewhat but is quite soft and easy to dish out, becoming liquid within minutes of exiting the fridge.

[heidih]

The weather has cooled and Instacart managed to bring me a pound of garlic heads instead of the ONE I ordered. But they are firm and plump. Serious Eats (declining but limping) did a piece on it which surprised me with the direction to salt & pepper aggressively! https://www.seriouseats.com/recipes/2020/10/roasted-garlic.html You do that as you like when using in my playbook. Anyway it had been forever so I test drove a head in foil, top cut off, drizzled with olive oil, Toaster oven in garage but still perfumed my desk area and was so good on my toasted 1/2 whole wheat bread. Off to roast another head now.I do as @andiesenji does with the pre peeled in bid bags from Korean market - but no access during pandemic.  Are garlic lovers roasting much?