Hollow Macarons

Today we will talk about one of the most buzz topics in the macaron baking world: hollow macarons. Why are my macarons hollow? How to fix hollow macarons? We will cover it all!

Disclaimer! Please read!

In the past couple of years, people have developed a weird fixation with “full” shells, to the point that bakers that end up with a shell with a small pocket of air think they are doing something wrong, and think their macarons aren’t perfect.

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This is unrealistic, and can be very demotivating.

Hollows should only be treated as an issue if the top of the shell is too delicate and crumbling apart, or if it’s accompanied by something else, such as ruffled feet, concave bottoms, cracked tops.

The fact that your macarons aren’t coming out 100% full all the time doesn’t mean you are doing something wrong, it could be the weather, it could be a couple of extra folds in the macaronage, or it could even be your oven.

If the shells have a sturdy top, have formed feet, a nice chewy middle, and a smooth bottom, you don’t have to worry or think you are failing at making macarons. Most likely the macarons will fill up after they mature with the filling in the fridge anyway.

Recently I wrote a full Macaron Troubleshooting post. And when I went to write about hollow macarons, it got way too long, so I felt like this topic deserved its own post. So here we go! Let’s dive right in and find out why your shells are hollow!

hollow macaron shells stacked.

Why are my macarons hollow?

This is probably the question I get the most!

And that’s probably because this is the most mysterious issue to troubleshoot. There’s just such a huge range of factors that can impact the fullness of your macarons.

The list you will see below may seem contradictory, such as: under baking, or over baking will cause hollow shells. However, that’s because it could be one or the other, and when it comes to macarons, you want precision. You want to find the sweet spot between over baking and under baking, which could be a difference of 2 minutes, or 5 degrees.

My biggest recommendation for troubleshooting hollow macarons is: once your macarons look perfect on the outside, the feet are awesome, the shells aren’t soft or crispy, the bottom looks nice and smooth, that’s when you should worry about troubleshooting hollows.

If your macarons are hollow with spread out feet, then figure out the feet first. If your macarons are hollow and with a soft shell, figure out the soft shell first.

Many times, the hollowness is a product of those other issues. So figure out how to perfect your technique so that the structure of the macaron is perfect, and then you can worry about hollow macarons.

Pockets of air or gaps in the shells

Sometimes your macarons have pockets of air in them, so they aren’t completely hollow, but they still have these gaps like in the examples below.

Sometimes the air pockets are like this, just random holes in between full shells. That doesn’t mean there’s something wrong with your macarons, or that you are doing anything wrong.

macarons with pockets of air in them
Africa Studio/Shutterstock

And sometimes there might be gaps between the top and the middle of a somewhat full shell like such.

macaron shells with gaps in the middle
 Photos and vectors/ Shutterstock

Sometimes, those hollow pockets or gaps will fill up as the macaron sandwiches mature for 24 or 48 hours. However, sometimes they won’t. Use the same troubleshooting below for pockets of air and gaps as you would for a completely hollow shell.

The pockets and gaps are way more likely to fill up, and indicate you are much closer to a full shell.

Some people actually prefer that their macarons have those pockets, because they make for a better overall texture after the macaron sandwich matures in the fridge.

macarons with hollow shells

What causes hollow macarons

Over mixed batter

Over mixed batter may cause hollow macarons. Sometimes your macarons may be looking like they have a nice shape, and the feet look nice, but folding a bit less will help solving hollows.

Experiment going easier on the folding and see how that goes. Even if your batter seems fine and flowing slowly but effortlessly at the figure 8 stage, just try folding a bit less next time.

This solved my vegan macaron hollow issues! And it will also work for egg white macarons.

Under mixed batter

Under mixed batter may cause hollow shells. However, you will definitely be able to tell, because the macarons will have a pointy top.

If your macarons have points on the shells, and they are hollow, then do the macaronage a bit longer next time.

Check out my videos on YouTube where I show the perfect macaronage stage in each video.

High oven temperature

High oven temperature could be the culprit for hollows. Sometimes only 5 degrees can make a big difference.

If your shells look perfect on the outside and you have hollow macarons, experiment with lowering the temperature by 5 or 10 degrees, pipe the batter between different trays, and experiment with different baking times/temperature within that range. Write down your results and see what you come up with.

Always have an oven thermometer to be able to tell the temperature inside the oven.

This is the thermometer I use:

Please read more about the oven here and how important it is to figure out your oven to make perfect macarons.

Low oven temperature

Low oven temperature can cause hollow macarons, because the inside of the shells isn’t having a chance to bake enough, so it’s not drying, which will cause the shells to be hollow.

Experiment with higher temperatures if you are staying on the low side, specially if your temperatures are below 300 Fahrenheit.

And like I’ve said above with the high oven temperature issue, just pipe the batter between different trays, and experiment with different baking temperatures and times within a 5 to 10 degree range. Write down the results always.

And also try to do this experiment with the same batch, to make sure that there aren’t other aspects affecting the results such as the meringue, macaronage, weather. But also continue to experiment with different batches if you don’t come to a conclusion.

Under baked shells

This is a big one right here. Under baking is known to cause macarons to become hollow.

That’s because if you under bake the shells, you won’t give the inside of the macarons a chance to dry and cook. So basically the inside of the shells simply won’t form, won’t have a nice structure.

To make sure your macarons are fully baked, try to wiggle a shell while still in the oven, if it jiggles, it needs more baking time.

If you are still uncertain, or having issues with telling if the macarons are done baking, remove one of the shells and cut it in half. If the middle of the shell is gooey, then the shells need a bit more time baking.

And if you are worried your macarons are getting too brown on the outside and not baking on the inside, consider covering the macarons with foil halfway through baking, or experiment with lower oven temperatures.

Resting too long

Resting the shells for too long will cause the macarons to be hollow, because the if the macarons sit for too long the meringue will loose stability. And the meringue’s stability is very important for the structure of the macarons.

Another aspect I noticed with over resting is that the top of the macarons will basically detach from the bottom, leaving a gap between the feet and the top of the shells.

And specially if you are in a humid climate, it’s important to find recipes that will call for no rest methods, as leaving your macarons resting on a humid climate is going to make them absorb the humidity, breaking down the meringue even faster.

Recipes that don’t call for resting usually have a higher ratio of powdered sugar/ almond flour to egg whites/ granulated sugar.

You can also experiment with adding egg white powder (not meringue powder) to the shells, as the egg white powder will add more protein to your meringue without any of the added moisture that the egg white usually has.

This is the egg white protein I use:

I add 4 grams of egg white protein for each 100 grams of egg whites, like I do on this recipe: Fig Macarons.

And some bakers also add cornstarch to their recipes to help this issue! On my French method recipe, I use a high ratio of almond flour and powdered sugar to egg whites and granulated sugar, and I also use cornstarch on the recipe, check out this Coconut Macarons recipe.

Broken meringue

Checking your meringue will be very important in trying to combat hollows.

Under whipped or over whipped meringue may cause hollows, because in both cases the structure of the meringue isn’t properly developed, which will affect each aspect of the macaron.

Under whipped meringue won’t have a stable enough structure to keep the air and water particles in place, and it won’t have enough air particles in it for that matter.

And over whipped meringue will have a broken and collapse structure which will also not be able to keep the air and water particles in place.

Please read this post, in which I explain the science behind the meringue and why it’s so important for it to be properly whipped.

Make sure the meringue is stiff, with peaks that shoot straight up. If the meringue has long peaks that are bending to the side, it’s too soft. And if the meringue is separating into chunks, it’s over beaten and therefore broken.

macaron shells with gaps in the middle, hand holding a bitten macaron.
 lito_lakwatsero/ Shutterstock

I hope today’s post was very informative, and that you were able to understand a little better what causes hollows, and how to fix hollow macarons.

For more information please visit the Macaron School page containing all the important articles that can help you learn macarons.

Here are some of them:

And for my complete list of macaron flavors visit this page.

hollow macarons two pictures showing from this to this, on how to learn to fix hollow macarons.

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34 Comments

  1. Thanks for your tips!

    I thought that my macarons were good, but then I saw hollows inside.
    I did oven temperatures tests and I found the perfect temperature, but my shells tuned golden.
    My white macaron was almost brown!
    How can I solve this problem???

    Thanks again!
    Kisses from Brazil!

    1. Oi Suzana!! What I do with white macarons is that I cover them with foil after about 7 min baking, so this way the foil won’t stick to the shells cause they will already be set, but it will prevent any browning from happening!!
      Boa sorte!

      1. Oi, Camila!!!

        Agora que vi que você é de São Paulo! kkkkk
        Perdão…

        Opa! Muito obrigada pela dica, vou fazer o teste!!!

        Parabéns pelo seu trabalho!

        Beijos

  2. Hi Camila..

    greeting from Indonesia
    actually its hard to made Idle Macaron

    kindly guide me if I need the only LOW HEAT or both of LOW & TOP HEAT
    when I bake the Macaron ?

    thanks for your help…. Your recipe made me confident to made Macaron
    since this not popular in Indonesia

    best rgds – seti
    in Indonesia

  3. Hi Camila!
    I’m troubleshooting hollow macarons (currently a beginner following your instructions and recipes. Thank you so much for all of your detailed instructions!) I’m wondering if I’m drying them too long because my tops separate from the rest of the body pretty distinctively. Since you recommend to bake one tray of macarons at a time, that means the 2nd tray is drying for 20 min longer than the first one. Any recommendations onto avoid over drying? I live in southern CA so my air temp is nice and average. Thanks so much!

    1. yes it could be from over drying. If you do feel like they are drying too long, you could keep the batter in the bag for an extra 10 minutes before piping. The batter in the bag, as long as it’s not exposed to air will be fine for a while. So make sure to secure the top of the bag and keep it upright so the batter doesn’t leak out the bottom.

  4. Is there any tips for high altitude baking?
    We tried all kinds of recipies and the main problem we have is macaroon feet/skirt spreading too wide and hollows. With added egg white powder no hollows but no feet either…

  5. Hi Camila!
    I finally got a perfect batch yesterday but I had to rest them for an hour. I live in Florida and humidity is my enemy. If I purchase a dehumidifier, roughly how much would it cut the rest time?

    1. I don’t know, it really depends, even here in my house, on days where humidity is basically the same, my macarons sometimes rest different because it depends on how stiff the meringue was, how much food coloring was added, how long the batter was mixed. You have to rest them until they form a skin and you can touch them and they don’t feel too soft or form a dent that doesn’t bounce back.

  6. I have struggled and struggled with hollow macarons and tried various recipes using the Italian and French methods. But then I tried your Swiss meringue method and it worked brilliantly! Hallelujah! I suspect my problem with the other methods has been the meringue and knowing when to stop beating. The way you explain the Swiss method in your videos I now feel really confident with this step of the process. Thank you so much for all that you do! I can’t wait to explore all the different flavour options and fillings on your webiste. Your work is beautiful.

  7. Thanks a lot for the tips and the important message, the must read “diclaimer”

    >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
    If the shells have a sturdy top, have formed feet, a nice chewy middle, and a smooth bottom, you don’t have to worry or think you are failing at making macarons. Most likely the macarons will fill up after they mature with the filling in the fridge anyway
    >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

    This is what exactly happening to me. I go crazy when I break one macaron to check after baking and felt so disappointed as everything look so okay. Actually these macarons fill up after they mature with fillings. Now, I am more confident and will try baking more

  8. Hi camilia. I tried ur macarons so many times. It came out perfect from outside with beautiful top and lovely feet. But when I check inside. It’s a kind of hollow . I baked 150’ c for 15 mins. Please help me and give me a suggestion on this. Thanks.

  9. Hi camilia. I tried so many times . It’s outside perfect with feet and smooth top but inside it’s every time hollow. I tried with egg white powder too. I didn’t find any changes.
    Please help me. Thanks

  10. Hello, My daughter and I have tried making about 10 batches of macaroons and they are hollow every time where the top detaches from the bottom. We’ve tried resting for longer and shorter times, mixing for shorter and longer times and doing the figure 8 and whipping the meringue differently. We are about to give up. Can you please help?

  11. I’m so glad I found you. I tried your method of making macarons and they turned out better than those other recipes. Thank you for your well written steps and videos that are so easy to follow.

    Yes, hollow cookies really discourages me to continue making it, but I like how you say it is ok if we have the feet and smooth tops and bottoms. I will try those tips to fixing the hollowness of these cookies.

    You are so awesome and I look forward to trying some of your other recipes. God bless you and your family.

  12. Hi Camila,

    I have been baking with your macarons recipes for a while now and last batch I got was perfect looking! Nice shine, proper feet, no pointy tops and perfect bottom. But when I broke one shell it was hollow 🙁 Even after maturing the shells were hollow. It was as if the middle was separated from top as it was a big gap between top and middle portion. Could it be overmixing? Thank you so much for such great recipes and the detailed explanation. You are awesome!

  13. My biggest question is knowing when they are done! I think maybe my hollow shells is because of the oven. But I can never decide how long to bake. I know the recipes say 15-20 minutes, but my macarons never juggle past 12 minutes so I think they’re done, but maybe they’re not?! I don’t know!

    1. that’s entirely possible, if they don’t jiggle, and if they are forming a nice bottom, and not coming out hollow, there’s no need to keep baking. Baking time varies a lot from oven to oven.

  14. Quick question…I think I finally figured out my oven thanks to oven thermometers. However, my macs come out looking perfect and do not stick to my mat but the top of the shell is very fragile and slightly hollow. I had to freeze several batters ahead for a party and when I checked a few in the freezer the tops just cracked. Any ideas?? Thanks, doreen.

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