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Uncapped honey fermenting in the comb

Fermenting honey

To produce honey, bees collect nectar from flowers and add enzymes from their honey stomachs. Once the mixture is stored in cells, the bees fan it with their wings until it dehydrates to a moisture content of about 16 to 18.5 percent. If the moisture content is higher than that, the bees simply won’t cap it. If cold weather arrives before the honey is capped, it will sit open in the hive and may eventually ferment.

Fermentation is the process of changing carbohydrates to ethanol and carbon dioxide. Fermentation in honey is no different than the process used in brewing alcoholic beverages. The yeasts that cause this biological process are found naturally in the environment and are called “wild” yeasts. The alcoholic content of fermented honey is not high—perhaps one or two percent—but knowing what to do with it is problematic.

Bubbles and a yeasty odor

Uncapped honey that has not fermented looks like normal honey. Once it starts to ferment, the cells are filled with bubbles and the odor of yeast can become quite rank. Sometimes foam oozes out of the cells and collects under the frames.

As a general rule, beekeepers who extract and bottle honey like to keep the uncapped cells to about 10 percent of the total. However, some go as high as 33 percent, which may require further dehydrating of the honey in order to keep it from fermenting in the bottle.

A lot of controversy surrounds the question of how harmful fermented honey is to bees and whether it can be fed back to bees. Alcohol is poisonous to them (as it is to most living things) but bees probably eat a certain amount of it in the normal course of hive life. I’m quite sure a small amount of fermented honey will not harm a hive, and many beekeepers agree.

What to do with it

However, if you have gallons and gallons of the stuff, I wouldn’t use it as a primary food source. Again, if you imagine bees in nature, you can see that they might encounter some fermented honey—but not barrels of it. The amount they eat should be a small part of their total diet.

Some beekeepers deal with the problem by extracting and boiling the honey which drives off the alcohol and kills many of the yeast. The downside is that boiling changes the properties of honey and increases the percentage of hydroxymethylfurfural.

For hobby beekeepers with only a few frames that contain uncapped honey, you can often give them a good shake and most of the uncured nectar will fly out of the cells. What little remains will probably not affect either the bees or the extracted honey. Use the “10 percent” rule and you shouldn’t have any problems.

Honey Bee Suite

Honey fermenting in the comb. Photo by Rusty Burlew.

Foam dripping from fermenting honey comb. Photo by Rusty Burlew.


  • I was in Hawaii recently and at a farmers market I saw fermented honey being sold for health reasons. It was being sold for 30 dollars for a pint sized jar of honey comb. I was told to eat it in half teaspoon doses. I can find no comments on the health benefit of fermented honey comb online. Does anyone have a comment on the health benefits of fermented honeycomb. Thanks

    • Michael,

      Sounds like it’s good for the financial health of the seller. It’s quite creative because most beekeepers don’t know what to do with the stuff. Just as in beer and wine, yeast that lands on the honey causes the glucose to break down into ethyl alcohol and carbon dioxide.

  • I have a whole medium super with sealed comb that somehow fermented. I would like to save the drawn comb, how to i get the fermented honey out of it. I don’t want to feed it back to the hive as it would cause dysentery

    • Luisa,

      I don’t see how capped honey could ferment. Was perhaps only part of it capped? In any case, if you have an extractor, uncapped what’s not already open, extract it and toss it. Or, turn the frame upside down and try shaking out the open cells. It’s probably just the open cells that are fermenting anyway. Or just let it keep fermenting. Eventually it will mostly bubble out of the comb and then you can shake out the remainder.

  • What if you just have a quart the has started smelling a little winey? Must have gotten water in it somehow. Do you just throw it away? I hated to waste it, if it is safe to feed back to the bees.

    • Marion,

      A little honey that has begun to ferment will probably not hurt your colony, but instead of feeding it to them and worrying about it, I would just use it for cooking. Think of it as using beer (or wine) and honey in the same recipe. If you use it for something spicy like barbecue sauce, you will never notice.

  • Hello,

    I am a new beekeeper and recently I harvested the honey. I had 70-75% capped cells and when I shook the frames no honey leaked from the cells. But now after bottling the honey it looks like it is watery!! It is so thin. Does that mean that it is uncured honey?

    I have about 40 pounds of it . . . what I can do?

    • John,

      Most beekeepers keep the number of uncapped cells to less than 10% of the total. Some go higher, but that usually requires some dehydration before bottling. I don’t know what you can do except take it out of the bottles, dehydrate it, and then re-bottle. Obviously, if you are going to try to dry it more, you have to do it before it ferments.

      Then again, if it is not fermenting, you may be okay. See this post.

  • Rusty,

    Thanks for your answer, and I have another question…
    How can I dehydrate the honey?
    It have been almost a week since bottling the honey and there are no signs of fermentation (smell, taste). So usually how much time does it take for uncapped honey to ferment?

    Thanks again for your help 🙂

    • The beginning of fermentation will depend on when and how much yeast is in there. You would have to heat the honey to dehydrate it, but you don’t want to get it very warm because that degrades the flavor. You could pour it into pans and put it in a dehydrator or put it in an oven that has a drying cycle.

    • Nabila,

      The fermenting alcohol smell comes from the alcohol that was produced by yeast. The honey had too much water in it when it was stored. It would be similar to drinking mead, hard cider, beer, or wine, all of which contain ethyl alcohol. Some people like it, some don’t.

  • Rusty– would it be possible to use your photos with permission for a high school lesson plan that will be made available on the National Ag in the Classroom website? Please let me know! I haven’t seen any other images as good as these!

  • Hi, I live in northern Ohio. My new hive has grown large and strong. They have two healthy brood boxes and a capped medium super, for winter. With Ohio’s cooler and cloudy summer, the ladies have filled another medium super, but is completely uncapped. I brought the super into the warm house. It shows no fermenting and is not running, out of the cells. Is this safe for human consumption? Or can or would they cap this honey? We are now in the first week of October. Thanks for your guidance.

    • Deb,

      It is absolutely safe for human consumption, but it may ferment. Fermentation doesn’t happen instantly, but it may very well happen in the months ahead. You can do several things. 1. Put the uncapped honey back on the hive for the bees to consume. This is what would happen in nature when no one is supervising. 2. You can save it in the freezer or refrigerator until you are ready to eat it. 3. You can extract it and keep it in the fridge for eating or for feeding back to your bees at a later date.

      My preference would be to give it to the bees. It will stay relatively cold in the hive and they will probably have it gone by spring. Put it under the other medium so they eat it first.

  • Brand new to beekeeping. Did not even think to check the hive over the winter, lest I disturb them in stressful weather. Realized two months ago that there was no activity in the beehive and peeked. All gone. Harvested our first bath of honey. Not sure if anything was capped or not. Smelled fine, albeit had a bit of a chemical smell to it. No foaming or oozing. Looked like honey, but very dark (not quite like molasses). Put it in glass jars, in the comb for about a month, then decided to try and strain the honey out of the comb. It has an odor to it. Not “bad” but distinct. Honey strained out nicely. It has the slightest foam on top. I cannot quite describe the smell. MAYBE slightly fermented. Taste is strong, as any dark colored honey would be, but it has a mild aftertaste. Again, not “bad.” We prefer sourwood honey, so could just be the difference in pollens. Is this honey likely safe to eat? Thanks in advance.

    • Christy,

      I’m not sure how you harvested your first batch of honey without noticing if it was capped or not, but in any case it is probably absolutely fine to eat. I’ve never heard of honey, fermented or not, making someone sick. Just enjoy it.

  • Thanks, Rusty. I know I am uneducated. No honey dripped out of the frames when we removed them, but they were not all solidly “sealed” in my view. The bees had all left; I’m not sure why. Some of the frames had what my daughter called “brood.” One thing I noticed was that the top of some of the frames had what looked like wax deposits on it. Now I am concerned it may have been dysentery. It was wax-colored (see the third photo down at The bees LEFT; very few we dead in the bottom of the hive. The best correlation for the smell is that it reminded me of flea powder my mom used to put on a neighborhood cat when I was a child.

  • So I have about 20 lbs of fermented honey. I was considering giving it back to the bees but after reading comments here have changed my mind. Can I use it to make mead? 20 lbs. is so much to just throw away!


    • Annie,

      When you make mead you want to control the yeast that is used. Since your honey is already fermented, you have no idea what kind of yeast is in there.

  • I had a hive rescued from a stump of a tree cut down.

    All was well and were filling out most of the frames. Then last time I checked them not a bee in sight. I had recently requeened them. The tops of the frames were real wet. They left honey and brood of all stages in the cells. That was about 2 mo ago. I see no sign of disease. Should I have them inspected? Any idea what happened?


    The honey is fermented. Can I safely put some of the frames on another hive? Or put a nuc in there in the spring?
    Any idea what might have happened?

    Thanks for any help.

    • Carol,

      I can’t tell where you are writing from and whether you are going into summer or winter. If you are in the northern hemisphere and going into fall, I would check the frames for evidence of a Varroa mite infestation (check for guanine deposits). A little bit of fermented honey won’t hurt the bees, but don’t give them a lot. They get drunk and disoriented just like humans. So if a frame is solid with just some fermenting on the edges, that is safe to feed. But not an entire frame of it.

      Anyway, I could be more helpful if I knew where you are.

  • Hi Rusty,

    Thank you SO MUCH for this wonderful site, and all of the information (and entertaining stories!) you’ve posted here. I’m so glad to have found you! This was my first summer beekeeping (I’m in Colorado) and I’m undergoing the usual trials and tribulations, and exhilarations, of a new beekeeper. Quick question – is it ok to put frames of capped and uncapped honey from a lost hive (I think I lost my queen and didn’t realize it until too late to save the colony, don’t think it was mites or disease) onto a surviving hive? Specifically the uncapped? It seems to be dripping down onto my bottom board. Too cold here right now (minus 5 degrees today) to open up the hive and see what’s going on. No other insects, no mice (I have a mouse guard on) that might be causing damage, so not sure what’s happening. But maybe I shouldn’t have given them the frames with so much uncapped honey?

    • Chris,

      I don’t think you are doing any harm, just making a mess. The uncapped honey may be fermenting inside the hive, which causes it to bubble out of the cells and drip down on the bottom board. As long as your bees have plenty to eat they will ignore the fermenting stuff. I wouldn’t worry too much, since you don’t believe it’s mice or other visitors.

    • Hi Chris,

      This is long after your comment was posted but we have had problems with uncapped honey/nectar in upstate NY. As you pointed out, uncapped frames can drip down. If the frames are above the cluster this can be deadly. Honey bees tolerate cold but but not being cold and wet. Extreme temperature fluctuations in winter seem to exacerbate this problem, perhaps because the liquid is expanding as it freezes, forcing it out of the cells. Sometimes it is possible to move uncapped frames to the sides so they are at least not in the center.

      • Li and Chris,

        Moving the frames to the side is a good idea. Also, you can turn the frames upside down and shake them out. That will leave only the thick, nearly-cured stuff in the frames.

  • Hi Rusty,

    I have a bit of a conundrum. I had my very first hive last year. I have been following you and your amazing blog for quite some time. You are the primary reason I decided to go foundation-less in my hive. Last year was great, and a great learning experience, however sadly my hive died sometime in early October. I am not certain why. There are many possible reasons, but that is not the purpose of this comment/question. As a result of the hive dying I was left with an abundance of frames filled with brood comb/pollen/honey and many frames of honeycomb that had not been completed. After my hive postmortem I cut up all of the mostly capped honeycomb and packaged it up for giving away and selling.

    I was left with about 15 frames of the other non-edible stuff that contained portions of brood comb or mostly empty or partially filled cells. I put all of these in a nice airtight container to hold for this year when I start up my hives again (I decided to do 3 hives this year). Sadly, upon opening this nice airtight container I was met with a very strong yeasty smell. Clearly the nectar has begun to ferment. Now to my question. As I run foundation-less frames I was counting on using these mostly completed frames in my 3 new hives to help them get started in the proper frame building formation. How much of these fermented frames can I risk putting into my hives with the new package of bees?

    Thank you in advance for your insight and response!


    • Isaac,

      Okay, I won’t lecture you about putting uncapped honey in airtight boxes, since it’s clear you understand the problem. What I would do is take the fermenting frames outside, turn them upside down and see if you can shake out some of the honey. I know it will be hard to do since they are foundationless, but support them somehow with your hands and try to get out as much as possible. Then take the frames and divide them up between colonies. As I said in the post, a little fermentation won’t hurt, but a lot isn’t good. Give each colony maybe one of the shaken frames to start. Later on, as the colony begins to build up, you can give them another. Continue until they are used up. A lot depends on how much shakes out. If nearly all the fermented cells are almost empty, you can give more frames than if quite a few cells are still full. I would just go slowly until the problem is resolved. Feral colonies deal with fermentation as well; it’s not a modern invention.

      • OK, that was along my line of thinking, but I hadn’t thought to turn them upside down to try and empty out the fermented nectar. Thank you!


  • Rusty, I am new to beekeeping. I lost my bees due to starvation half of all frames are uncappped and I believe to be fermented. Do I shake the frames out or will they be able to work with the uncapped honey. Don’t know really what to do.


  • I have a question I had a bee hive relocated from out under my cabin. I collected the honey, honey combs, and kept the pollen filled combs too. I put in clean jars and put up in cabinet went through 3 jars and gave 2 away all were delicious. But today I opened the second to last jar and it released gas and smells fermented. This jar happens to have the most pollen in the comb. Do I need to trash it or can it still be consumed by humans? I was told by the bee keeper who removed the hive that the pollen(bee bread). Was very healthy to eat and said I should put it in the jars with the honey. The combs were not fully covered by honey in the jar. Was this a mistake to mix the two and was it a mistake to not cover the combs all the way?

    • Cindy,

      Whether you trash it or not is up to you. Some people love the taste of fermented honey, some do not. Bee bread itself is fermented, so adding it to honey is like adding yeast to grape juice: it causes fermentation. But honey keeps oxygen out, which slows things down, so covering the pollen with honey would most likely reduce the fermentation.

      On a side note, bee bread is very healthful for bees, but less so for humans because it is difficult for us to digest. Personally, I think pollen tastes horrible. Honey has pollen in it already, but not enough to taste bad.

    • Antoinette,

      If you like richly-flavored honey full of micronutrients, it is the very best and my absolute favorite.

  • Hi Rusty – great site!

    Back in 2012, you commented that you don’t know how honey could ferment if it were capped. Well, today I pulled a few frames from my hives, which I started this spring. I only harvested the capped portions from the frames I pulled, and can say with certainty that it was 98-99% capped. All of it has a distinct smell and taste of wine or mead. It is nice and dark and thick, and somehow fermented. I only have about a gallon, but it makes me wonder about everything I left in the hive.

    Do you have any suggestion(s)?

  • It was not bubbling or foaming, but the moisture content was around 19%. I met with some local beekeepers and they confirmed that it smelled and tasted fermented. However, they were also puzzled that it came from capped comb. I had pictures of one of the frames and it was 100% capped. After some conversations and more research, I decided to give all the honey back to the bees. I am planning on feeding through the fall, hoping they survive the winter, and will try again next year. If I get the same thing next year, I will probably try moving the hives. We had an unusually wet summer, and my hives are in a very humid environment, along a tree line.

    • Ben,

      I hope you tried some of the honey first! Some cultures consider fermented honey a delicacy and I know beekeepers who prefer it over any other kind.

  • Yes, absolutely, we tried it. It was peculiar, but the flavor was “distracting”…. I considered keeping some for a recipe I make, but decided the bees would like it more than me.

    • Ben,

      That’s good news; I’m glad you tried it. Personally, I don’t much care for it either, but I didn’t want you to miss an opportunity. Your description of it as “distracting” was perfect.

  • Hi Rusty,

    I am a beekeeper of two years now. Recently, I purchased a bunch of hives from a friend who was turning 76 and decided that he was cutting down on the hobby. With the purchase, I had discovered that many of the brood and super frames were filled with both capped and uncapped honey. I don’t have room in my chest freezer to put all the frames into in order to store them for 3-4 months. So, what should I do with the uncapped honey? These uncapped frames have been kept indoors and open to the air for about 1 and a half months. If I extract the frames, will the machine only take out the honey of the uncapped cells, or will it also open the capped honey and take out that too at the same time?

    • Andrea,

      If you turn the frames upside down and shake them hard, any uncured honey should fly out. If none comes out, the honey is very close to being cured. If they’ve been stored already for a month and a half, and they are not molding, I would say they will probably keep till spring. Why not just save them for the bees as is?

      On the other hand, I know people who spin the frames and have had good results separating the uncapped honey from the capped. I would keep a close eye on it, though, just to be on the safe side. You don’t want to get an unbalanced comb that ends up falling out.

      If you do try to separate with the extractor, please let me know how it works. I’m very curious about it as a separation technique.

  • Rusty,

    I opened a hive today and definitely got a yeast odor. I’m in St. Louis. No supers on yet so the odor is coming from one of the frames in one of the deeps. Do I need to go through the boxes and find the source or will the bees get rid of it?


  • So glad I found this site! You say to use a dehydrator to dry out the uncapped honey. Do you happen to know what temperature would be good and for how long?

    • Sabrina,

      I don’t know, but I would keep it as low as possible, like 100 F or less, and then test periodically.

  • Seems unlikely but I figured I’d ask, would the bees ever leave honey uncapped during warm weather (ie weather that would allow for curing)?

    If so, why?

    At what temp (presumably in the fall) would the bees stop curing whats uncapped?


  • Hi Rusty,

    First, thank you for sharing your knowledge and expertise in beekeeping. I faithfully read all your email posts. I have a question I hope you can answer. This is the first year that I have harvested honey from my hives. I am naive and not sure how to determine fermentation in harvested honey. I do not detect a yeast odor and the honey has a great flavor. The pail (covered) that I have kept the honey in has a very thin light foam randomly around the top. Is this an indication of fermentation??

    From reading your posts fermenting honey is not harmful if consumed. Will “creaming” the honey prevent continuing fermentation?

    How “suite” of you to respond.

    Thank you,
    John Wheeler

    • John,

      The tiny bubbles at the top of honey are often just bubbles of air that got incorporated into the honey during extraction. If they are small, they can take a very long time to come to the surface. But if your honey begins to take on atmospheric moisture, it could ferment. The best way to test is with a refractometer. And yes, creaming the honey helps to keep it from separating and fermenting.

      But if your honey was fully capped before extraction, with no more than about 10% uncapped cells, and if you keep it tightly covered, it should be fine.

  • Rusty,

    Thank you for your timely response, valued, and sage advice. You described what I am seeing on the top of the honey. As a relatively new bee handler I was uncertain what I was seeing and certainly do not want to give altered honey to friends and neighbors.

    I always read your postings and use your index as a respected source.

    Thank you so much for your dedication,

    Yours in the buzz,
    John Wheeler
    Love your photography !!

  • I presently have a shallow that is 100% capped. I noticed on the ends of some of the frames a change in color of the caps. My first thought was there was brood. Upon checking I found fermentation. After pondering the situation I thought maybe I could uncap the unfermented area and try extracting. To my surprise, I found fermentation bubbles in these cells as well. My hydrometer read 22 percent when I checked the honey in these capped cells. This honey does not taste fermented even though I can see the bubbles. I have set aside this shallow and will extract last. I am wondering is while it still taste good could I use a stabilizer like is used in winemaking to stop the fermentation?

  • Two years ago honey bees took up residence in a Rubbermaid container with lid. I like bees and they stayed. I tried to get ANYONE beekeepers!) to come get the bees, but no one would do it for free, so I just left them alone. Last week we had torrential rains and freezing temps, the bucket cracked (I was bereft!) filled up the bucket and all bees drowned. So many bees that I could not even fathom so many living in there. There is a lot of comb and honey, but besides being heartbroken, it smells very not good. Can any honey be saved? Thank you for your time!

    • The bad smell is the dead bees rotting, but you can salvage the honey. I would wash the combs first, to remove any decaying matter. They you can just squash the combs and put them into a strainer to collect the honey.

  • Thank you so much for such a quick reply! I am very happy the bees hard work will not be in vain. Thank you again and take care!

  • Just checking hives this weekend. Fall flow has started about a week ago. We are seeing these bubbles in almost all the hives. It seems awful quick to ferment. No fermenting smell. Not planning on extracting it. Plan to leave fall stuff on hives for bees. I guess they will deal with it.

  • Hi Rusty, I am thinking you have seen a lot & I have stumped everyone else I’ve asked. I’m wondering if you can help me figure out an answer or know someone you can direct me to. I had the opposite happen, fermenting capped honey.

    I extracted my honey with an extractor. When we were done spinning we noticed a layer of liquid on top once it all settled.

    I let the honey sit for a day tightly sealed. We were going to bottle it & noticed a fermenting smell upon opening the container. My daughter likened it to vinegar. I drained this liquid layer off & cooled the honey, so I could dry the rest of the liquid stuff off. The honey itself tastes fine. I drained off almost 5 cups of liquid from 5 frames though. The frames were almost completely capped & full on both sides.

    We extracted it at our bee club meeting & had quite a few seasoned bee keepers. They all agreed the frames were ready for extraction. They are all stumped as to why we had this layer of liquid & why it already smelled fermented as it was overnight.

    Next concern is what about the hives as this is what we pulled from the frames. I have two hives & do not know if it is from one hive or both.

    They do have a good amount of stores & both are healthy strong hives. I did a mite check in spring and this past weekend, no mites.

    I’m just concerned their stores are too high in moisture as the honey we extracted was taken from their hives about 5 days before we extracted. We froze the frames for 2 days & then thawed them. With 5 frames, so almost 1 cup of liquid per a frame if it was both hives otherwise it’s even higher if it was just one hive.

    So my questions are:
    1. If the honey is capped why did it happen, what went wrong?
    2. Should I heat the honey I extracted to stop the fermenting?
    3. What about the bees & their stores? Will they be able to consume this through the winter & survive?

    I hope you can shed some light.

    • Brandee,

      1. Although I have heard stories like this only a few times, it’s been often enough that I think there must be something to it. The only reasonable explanation is that the bees capped the honey before it was fully cured. But why? I don’t know.

      2. I’m not sure that heating the honey would do much good. If you get it hot enough to pasteurize it, you’ll be ruining a lot of the flavor components. Also, you would need to seal it immediately while it’s still hot, or run the risk of inoculating it again with yeast spores. Why not test the remaining honey for water content and see what it is now that you removed the surface water. At least that would give you an idea of how far off it is. Someone in your bee club is likely to have a honey refractometer.

      3. Don’t worry about your bees. They evolved with honey that often fermented with no beekeepers around to fret about it. They will do just fine. Just make sure that have enough food all winter because if the honey drips out of the hive, they could run short. When I have honey fermenting in the frames, I give it to my bees to clean up and never had a problem with it.

  • Not sure you guys can help me, but I had 2 hives die out, weather-related. I was thinking about getting a package of bees and installing them in 1 of the base supers everyone talks about, feeding frames back, but how do you do that? I’ve got mostly capped frames. Do I uncap them and slip 1 or 2 frames back in the box so they can clean them out and reclaim the good and fermented honey? I feel like I heard you have to spray them with water so that the bees will actually clean them up, is that true? And if I install them to reclaim, do I need to add a pollen patty to help them?

    • Crystie,

      To feed frames of honey to a package, simply put the frames of honey near the cluster, on one side or both. Do not uncap it (causes robbing) and do not spray it with water (can cause mold and/or fermentation).

  • You say when it gets too cold the bees will stop capping honey, but at what temperature does this happen?? Does this happen in the fall, or does this happen in the winter after they have formed their winter cluster?

    • Shelley,

      I can’t give you an exact date. But as you probably know, if you hang wet laundry outside in winter, it never gets dry. That’s because cold air won’t hold as much moisture as warm air. At some point, no amount of fanning will dry the honey, so they just give up. They don’t fan honey when they are clustered, but they likely give up on it before that.

  • I have fall honey from my hives which is very dark in color. (Northwest Florida) We extract from comb that is over 80% capped. The fall honey is always stronger in flavor and smell. However, we had at least 25 gallons that the smell is stronger and different than normal. How can I tell if it is fermented? Our honey doesn’t resemble the photos in color and it’s not foamy.

    • Wendy,

      The smell of fermenting honey is easy to recognize. It smells like beer or yeasty bread or newly opened wine. You may just have nectar that is darker than what you’re used to. Since all years are different, it’s hard to compare year to year.

      Still, only 80% capped is risky. I recommend extracting when honey is 90% capped, just to be on the safe side. But if it’s not foamy, that’s good. The color doesn’t have anything to do with fermentation, so that’s irrelevant.

      Maybe you can ask some other people to smell it and see what they think. Usually, people pick up the yeasty scent almost immediately, but since you’re used to the scent, it may be harder to distinguish.

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