Food for Thought: "Science: Green Garlic Working on a pasta sauce recipe for an upcoming issue, test cook Erika Bruce noticed that fresh garlic cloves sometimes take on an odd blue-green shade when cooked with acid (tomatoes, in this case). Under acidic conditions, isoallin, a compound found in garlic, breaks down and reacts with amino acids to produce a blue-green color. Visually, the difference between garlic cooked with and without acid can be dramatic, but a quick taste of the green garlic proved that the color doesn't affect flavor." From America's Test Kitchen Newsletter, September 2004

Hi. I would really like some help with this if possible. I have been marinating my own garlic cloves (peeled) in oil for a couple of years now and every now and then I end up with a batch where many of the cloves turning green after a week or so and the oil turns hazy. I then pick our the green cloves and throw them away. My question is Why do some turn green, are they off or poisonous ? I am too scared to eat them and I worry that the green ones might turn the oil bad or send the others green if I leave them in the jar. I hope this all makes sense to someone as everyone I have spoken to about this has no idea. Thanks for your help. EW

You can read an explanation of why garlic turns green sometimes on our "Garlic Q&A Page." In this case, however, it could be that the garlic is actually growing some old fashioned mold. You don't say whether you are refrigerating your marinating garlic but if you are, that's why the oil is turning cloudy. It does that once it falls below room temperature. I do need to warn you that you are opening yourself up to the risk of botulism by marinating the garlic in oil. You shouldn't keep it on hand for much longer than five days in the refrigerator.

Hi, My wife's mother says never refrigerate garlic. We brought some garlic home from her house and it was much stronger than the garlic we prepare. Is it good to do this or is this or not? It's pretty strong!!! Thanks: Tom from an Italian family. TM

Here's a quote from the Garlic Store's website about how to store garlic: "A ventilated garlic keeper is fine, and looks good in your kitchen. Garlic stores well at room temperature as long as it is not sealed up. The ideal storage for garlic is at 55 degrees F and at 55% relative humidity. Never refrigerate garlic, or it will try to sprout prematurely. And never ever store garlic in oil at room temperature. It is a hotbed for botulism." Consider, too, that your mother-in-law may have a different variety of garlic than you normally use.

How long does jar a minced garlic keep after having been opened? EO

I can't find a definitive answer for this and I don't use it myself. If there isn't an expiration date on the jar, perhaps you should call the company that made it.

My father-in-law says that he uses the root of garlic to keep his blood pressure down. He says it doesn't have the smell or taste of garlic cloves, but he chops it up and puts it on his food. Do you think he means the onion looking part of garlic or is there actually a root (other than the bulb)? Thanks for your time! D

Garlic does have roots attached to the bulb and they are edible but, unless he is growing his own or knows of a local farm, I can't imagine where your father-in-law would get them.

Hi, I have been reading about garlic turning green when cooked with certain things but I have tons of garlic growing in the garden, after I harvest it and it begins to dry the cloves turn very green. I have always thrown it away because I was afraid to use it. Is it o.k. to cook with? Thanks, J

The What's Cooking America site has some Garlic Tips that might give you an idea of why this is happening with the garlic from your garden.

Dear Sir/madam, I read the following article on Garlic and it was quite interesting: "Q: Is there a way to fix garlic without getting bad breath from it. My husband loves garlic and I don’t like to have bad breath for 3 days? CN" "A: Cooking garlic will take away some of the breath-killing properties. For some longer cooking recipes, you might also try adding whole garlic cloves that can be be removed before serving." Is it not true that when you roast garlic there is no smell or after effects? I have heard people who eat roasted garlic and it doesn’t seem to smell. If this is the case you may want to update your site. Kind Regards, C

It's true that roasting garlic may diminish the bad breath effects since it is a method of cooking it. I've noticed sometimes it doesn't affect my breath and other times it does--perhaps it is due to the length of roasting?

How long does garlic that is canned (glass container) stay good after opening it and putting in refrigerator? SS

Oh, I'm tempted to say it wasn't good to begin with because fresh cut garlic is always better but you might find that rude. Your glass jar should have a use-by date on it.

I have tried cooking with a couple of heads of garlic, switching pans and methods each time, and for some reason these seemingly perfect cloves give off a strong paint smell. What could cause this? The only difference is that the skin is purplish but I thought that could be normal. I am using the same method as I always do, it smells fine minced and then when it starts cooking...BAM shot to the nose. It tastes the same, like cooking spray paint or something. Thanks for the help. B

Do other people smell this same odor? It could be just the way your olfactory system processes this particular variety of garlic. There are many different varieties, perhaps you should stay away from the type you have been cooking and see if you can find one that is more pleasing to you.

How much of 1 teaspoon of liquid garlic equals how much in powder form? Thanks M

One half teaspoon liquid garlic is equal to one clove of garlic which is equal to 1/8 teaspoon garlic powder or 1/4 teaspoon granulated garlic.

Our garlic bulbs are stored in a dark, cool place but they are sprouting in abundance. is there a better way to store them and is it still good to eat this garlic? and the sprout? thanks! TS

Your garlic may have been a bit old when you bought it. Our friends at Cook's Illustrated have done tests on sprouted garlic. They report that the sprout is bitter and should be removed but that the rest of the clove is fine. They also discovered that garlic is best stored at room temperature in paper bags or a ceramic garlic keeper.

We bought a 3 lb refrigerated tub of garlic -ha - and it has been about a couple of months , it has turned a little darker yellow color , so we froze some ???? not sure if that was a good idea and now the rest of it is even darker yellow and has a really strong smell....how do you know when garlic goes bad.... JJ

Well now, that's quite a bit of garlic, isn't it? I suppose the best indicator of it going bad would be mold. Aside from that, your supply sounds a little icky--go with the old adage "when in doubt, throw it out."

What is the difference between a button of garlic and a clove of garlic? Thanks, H

No difference, just different ways to express it.

Is there such a thing as "old garlic?" If so, what is the difference between regular garlic and old garlic? T

The answer is age as far as I know. Kept properly, garlic will last for quite some time but fresh, younger garlic will have more flavor. In the article "Herb of the Year 2004: Good Old Garlic," the 'good, old' part means reliable.

Does cooking garlic take away from its health benefits? I heard from a friend that if you cook it fully (sautee, brown, etc) you will not get the full benefits. Is this true? Thanks!!

Check out this article from the Garlic Central website: Garlic Health Benefits: Summary.

Can you tell me where to find recipes which use pickled garlic in them? Would pickled garlic be useful in certain meat dishes? Thanks! LAK

Now that you mention it, I've never seen a recipe that actually called for pickled garlic. I think it would make an acceptable substitute for fresh garlic in recipes like salads and salad dressings, relishes, sauces and, yes, many meat dishes. Think of pickled garlic along the same lines as you would capers and you should find lots of ways to use it.

If I cook shrimp scampi with minced garlic will it turn to liquid? If not how do I make scampi like they do in restaurants? EJ

The liquid in shrimp scampi is usually a butter sauce. You will find a link to a scampi recipe in the article "Herb of the Year 2004: Good Old Garlic."

Hi! I looked over your very informative website but couldn't find an answer to my query. My father grows garlic but it doesn't look like the garlic you buy in the stores...it's not cloves, per se, it's more like an onion. It smells garlicky, though maybe not as strong, and it works out fine cooking, but we are baffled by it's "looks". Any thoughts? Thank you very much, MW

Are we sure that your father isn't growing shallots? They are similar to garlic in shape but peel like an onion. Read more at "All About Shallots."

Why does garlic turn brown when pickled ???? MS

Not all of it does so I suspect some sort of preservative is being added.

Is there a way to fix garlic without getting bad breath from it. My husband loves garlic and I don’t like to have bad breath for 3 days? CN

Cooking garlic will take away some of the breath-killing properties. For some longer cooking recipes, you might also try adding whole garlic cloves that can be be removed before serving.

What is the difference of Minced garlic and fresh garlic and can you use minced instead of fresh when cooking? TAH

"To mince" is a technique rather than a type of garlic. Minced garlic is fresh garlic chopped fine. You can accomplish this with a knife or a garlic press.

Is it possible to eat too much garlic ? I eat alot of it. JM

I offer you this link to information about garlic from the Memorial Sloan-Kettering Cancer Center so that you can decide, based on your own health.

I have never roasted garlic and am planning on trying your "experiment" with the slow cook method. Does roasted garlic need to be used immediately or can you tell me how long it can be stored and is there a best storage method? Because of the energy consumption it makes sense to roast several heads at once. Thank you for your help. LRC

I've never been able to keep roasted garlic around for very long but I don't think I would try to hold it much longer than a week in the refrigerator. Be sure to wrap it airtight or squeeze out the roasted cloves into a small container and cover with a thin layer of olive oil.

My doctor spoke of the wonders of garlic butter. She said she cooked raw garlic in the oven and then used it like butter. Can this be done in the microwave? What are the temps and times? thanks! KC

Check out the article "The Great Garlic Roasting Experiment" for many different ways to make your garlic spread like butter.

I got some strange garlic from the supermarket the other day. It looked fine on the outside, but seemed a bit mealy when I started to mash it. Instead of a pungent garlic aroma, it smelled weak, with a very faint whiff of ammonia. I didn't use it, so I don't know if the flavor was affected. This has happened twice recently. Has anybody else experienced this? Any explanation? B

I wouldn't have eaten this garlic either. Most likely, the garlic has been dried and/or stored improperly causing it to go bad. I haven't experienced this myself; anyone else out there?

I have read about garlic turning green. Mostly, the green is stated to be coming from acid. Over the many years, I have made garlic butter for our crab, and it hasn't turned green. Now, my garlic is turning green, and I don't use any acid. I have not changed my pot or utensil. I agree that it doesn't change the taste, but it's not appealing. I used the same garlic in a tomato base dish, and it didn't change color. Why all of a sudden is the garlic turning green in my butter? TH

This landed in my mailbox recently and may answer your question: "From the Food Safety.com site. Practices -- Cooking. Why does garlic turn blue-green when cooking with butter and lemon? Rating: 97. Garlic contains sulfur compounds that might react with copper to form copper sulfate, a blue or blue-green compound. The amount of copper needed for this reaction is very small and is frequently found in normal water supplies. The other sources of copper might be the butter or lemon juice. The garlic is safe to eat. To prevent this in the future, do not refrigerate garlic and store the bulbs in dry air for 32 days at above 70 F to 80 F before use to prevent formation of the green or blue-green pigments. PREPARED BY: Angela M. Fraser, Ph.D., Associate Professor/Food Safety Specialist, NC State University in July 2004"

Hi, I use garlic but not to often, how do I store unused garlic? and what is a clove of garlic, thxs AF

You can get fancy little "garlic keepers" which are ceramic jars with holes in the sides to allow for air circulation but I find garlic lasts for weeks along with onions and shallots in the basket I keep on my kitchen counter. When you break a bulb of garlic of garlic it will fall into many cloves. More on garlic: "All About Garlic."

Hi, I want to dehydrate a pound or so of garlic. I have been told by others that this can be done in the microwave. Can you tell me more about this technique? KL

Although some people say that you can dry herbs in the microwave (others say this is a good way to start a fire), seems to me that garlic wouldn't be a good choice for this method. Garlic is really a vegetable and it would more likely cook than dehydrate. An electric dehydrator would be a better method.

Hi! Since I cook a lot of meat in which I like to put garlic paste for flavor- I often make a paste of garlic (grind it in food processor) and store it in the fridge. it usually lasts a week or two. but this time I stored it in a glass bottle (with a tight lid) and it turned green and that too in a matter of hours. I am wondering whether to use this garlic or not. what do you say? thanks, s

See the explanations below and on the Garlic Q&A page for why garlic turns green. You should also be advised that this isn't the best method for storing your garlic since it is a good candidate for botulism. It would be safer to freeze your garlic puree in small packets or containers.

Recalling that prisoners chewing garlic while carting away bodies did not succumb to the Great Plague leads me to consider that perhaps garlic could also be effective against bird flu. My query is this:-What is the most effective way to buy and store garlic, in its most powerful form, for just such an eventuality? Thankyou SJ

Interesting food for thought there. I refer you to Garlic Central.com where they cover nearly every aspect of garlic including health benefits and storage.

When a recipe calls for roasted garlic, can you substitute minced garlic in olive oil (store bought). What exactly is the difference? Flavor? What about garlic mashed potatoes? Should I use roasted garlic? DJW

Roasting garlic gives it a more mellow taste and takes away that familiar bite of heat. What you use depends on the flavor that you want. Raw garlic has more of a presence than cooked or roasted garlic. Many folks simply boil whole garlic cloves along with the potatoes for garlic mashed potatoes but you could also add roasted garlic as you mash them.

How do I store fresh chopped garlic and how long will it be good for? Is it ok to put it in the fridge in a jar? thank you!! JR

Garlic is best used just after chopping. It could be (and should be) stored chopped and submerged in oil in the refrigerator for a week or two.

Hello everyone:  About roasting garlic. Your ways sound wonderful albeit a lot of energy used for such a small mass. We also love garlic in nearly everything. Consequently I came up with such a simple method. Try it, bet you'll like it. Just take a full head of garlic, or more, clean the cloves, put them in a micro wave friendly container. I use a Corningware cup or glass custard cup. Cover the garlic with virgin olive oil...cover with something, like waxed paper, parchment, or just plain paper towel, folded as necessary and microwave for one minute, depending on the amount of garlic and the power of your microwave. Let stand a few minutes. This leaves you with soft garlic that can be tossed into sauces, potatoes, vegetables...wherever you like it. The bonus is some lovely garlic flavored oil that can be used anyway you wish.  Your site came up as I went hunting for info on annatto....what a treasure to stumble upon. Thanks, E

Thanks for sharing your idea for a quick-roast garlic. Glad you like the site!

I just read the above message about green garlic. My garlic, cooking with lemon and chicken, in a dish I have made before, with utensils (all stainless) turned an unreal turquoise green-not a plant color-I threw out an entire chicken because this was very scary looking. I have been cooking forty years, including a professional stint as a sous chef. This is a new one on me.

New one to me too! I think I would have done the same thing.

I am not much of a gardener, but I would like to be! I have a garlic bulb that I have not pulled apart or used and it is starting to sprout in my kitchen window. I would love to plant it in a pot if at all possible, but I am not sure how to start or if I can do it at all. Do I pull it apart? Do I plant it with anything? Do I leave it outside or in? Oh and just FYI I live in Texas where the weather changes all of the time--if not just plain HOT. Currently- 60 degrees outside. JM

Since it is so widely available I haven't really tried to grow garlic. Your experiment sounds like fun, however, so I encourage you to try it! In a nutshell, you should pull the cloves apart, plant them about two inches deep with the end that is sprouting pointing up. Keep the pot in full sun and water regularly but don't keep it soggy. Find lots more of the information you need at this section of the Garlic Store.com.

While searching the net for an answer to my green garlic, I stumbled upon your garlic q&a. I roasted plum tomatoes that were with sliced in half and mixed with sliced garlic, salt, sugar and dried thyme. After roasting the tomatoes for two hours, I noticed that the garlic turned green. I'll continue my search for an answer. N

I finally found the answer to this puzzling situation. Here is the quote from the "More Tips" page: Food for Thought: "Science: Green Garlic Working on a pasta sauce recipe for an upcoming issue, test cook Erika Bruce noticed that fresh garlic cloves sometimes take on an odd blue-green shade when cooked with acid (tomatoes, in this case). Under acidic conditions, isoallin, a compound found in garlic, breaks down and reacts with amino acids to produce a blue-green color. Visually, the difference between garlic cooked with and without acid can be dramatic, but a quick taste of the green garlic proved that the color doesn't affect flavor." From America's Test Kitchen Newsletter, September 2004.

I have been making a spicy salsa which contains lots of garlic that is mashed into a paste. I wanted to bottle this as part of a gift basket for family and friends. After heating the salsa for bottling purposes, the significant "bite" of the salsa has disappeared. What can be done to safely bottle my salsa without losing the raw garlic appeal. JJ

The processing of canning is cooking the garlic, as you suspect, and I don't know of any way around that. Maybe you could make an attractive decoration for the lid with heads of garlic and suggest that recipients chop it up and add it to the jars after opening.

I know it sounds impossible, but I got too much garlic in the soup I was making. I know if you get too much salt cook potatoes in the broth and that absorbs salt any hints on too much garlic? DH

The only remedy I know for this problem is to make another batch of soup without garlic and mix the two together.

My garlic is in the flower or blossom stage right now. The blossoms (not the scapes) look like miniature garlic cloves, each about the size of a piece of orzo pasta. I tasted one and it was a delightful garlic taste. My question: Can I use these blossoms in cooking or salads?

Okay, I confess, I've never seen blooming garlic! The general rule is that all herb flowers are edible so I'm certain you can cook with yours. You might want to take caution that you don't overpower a dish if the flavor is strong like that of chive blossoms.

Hi, My neighbor gave me a whole bunch of garlic that he had already peeled - I have about 60 cloves of garlic. How do I store them - I am a single parent whose son is off at college and don't cook that much anymore - any suggestions - I would hate to have them rot or spoil. thanks D

Gee, that's a lot of garlic. It isn't going to keep very long. You might want to pickle it as in the recipe at "All About Garlic" or make it into garlic butter as described in "Compound Butters Rescue Plain Foods."

Who first brought cultivated garlic to the New World and in what part was it first grown? Thanks, P

I can't find the exact answer to your question but I did discover that Christopher Columbus brought onions to the Dominican Republic in 1494. Soon they were introduced to Mexico and Central and South America. From there they made it to North America. I don't think it would be such a leap to think that garlic followed the same trail.

I have bought some Garlic in a pot and have planted this within my herb patch, in the garden. How do I know when to dig it up to use it? Also I have planted some Chervil in the same area but it is starting to go a red colour. Before planting it I broke up some of the roots in case it was a little pot bound and I am also keeping it well watered. Any Ideas??

After the plants shoot up flowers you will want to cut the stalks back to allow the heads of garlic to use all that energy to develop. Leave a couple of flowers as a guide; when they begin to brown and wilt you know they are almost ready. Stop watering for a few days and then pull the heads out of the ground. Allow to dry out of the sun for a few more days. One reference book tells me that chervil does not take well to transplanting and doesn't really like full sun. Perhaps your plant is experiencing shock that it may or may not recover from or it's just getting too much sun? Can you check back with the place you bought it from to ask questions?

I have several recipes that call for a "garlic button". What-the-heck IS a garlic button? I would appreciate your input. Thanks. C

Cloves of the garlic head seem to go by many names. I've never heard them referred to as buttons but I have heard them called "toes" or "buds." These must all be regional references.

Hi. I have had a very strange experience with garlic recently. While I was preparing it (I swear to all that is holy) it turned green! I have two other witnesses and they too used cloves from the same garlic bunch and it turned green while cooking it on different occasions. And yes I used the same garlic (hey I was curious) and it didn't turn. I have never heard nor see such a thing. Could it be that the garlic was bad? I thought that maybe it was a reaction to using a non-stainless steel utensil, but I used a garlic press and used a plastic spoon to scrape the garlic off. Mind you that all the utensils (marked stainless steel or unmarked)that I used that day were the same utensils I use on a regular basis when preparing garlic and again I have never had that happen. Please help me figure this out so that I can buy garlic and use it without fear of it turning green.

Never heard tell of such an unusual phenomenon before! Only idea here is that maybe you had a green substance like another herb or spinach on the cutting board or in your saucepan. Readers, ideas?

Garlic is good but the after affects are not so good on your breath and body. Does powdered or pickled garlic have the same affect as fresh garlic?

Garlic really is the seasoning we love to hate! Although recent studies are showing that garlic may help reduce blood cholesterol, block certain cancers and reduce risk of infection, there is still the pesky problem of bad breath. Jean Carper of USAweekend.com (4/2/95) reports that all forms of garlic, even powdered, can have health benefits. "Garlic infuses your blood and lungs," she writes, and may give off odor for 4-18 hours depending on your body's individual reaction. I have found that cooking garlic seems to lessen the negative effect on your breath. Pickled garlic is cooked briefly so it probably falls into a middle range between raw and powdered. You would use far less powdered garlic so I consider it less potent. Should you find yourself with garlic breath, you might try one of the suggestions found at Epicurious.com. They recommend eating fresh parsley, a coffee bean or a bowl of lime sherbet. But Carper warns these or other measures only serve to dim the problem. You have to let it run its course.

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