Copycat GU gels

Copycat GU Gels

Well, that didn’t take long.  I really didn’t want to make a gel out of maltodextrin.  Without really knowing much about it, maltodextrin just seems like a weird laboratory concoction that companies must use because it’s cheap or shelf-stable or something.  It can’t possibly be good for you and it’s about as far from a whole food as it gets.

So why did I change my mind?  Science.


What in the world is maltodextrin anyway?  It’s a powder that is created from a starch (usually corn, but any starch can be used, like wheat or tapioca) by adding some acids and enzymes.  It is technically a complex carbohydrate, but it acts even faster than simple sugar in the body.  When you are exercising hard, you want the fastest fuel available (in other words, something with a super-high glycemic index) to get glucose to your muscles and maltodextrin is it.

For a really in-depth analysis of carbohydrates specifically for running, check out The Science of Energy Gels. I love this site!  Jonathan Savage has broken down exactly what the most popular and obscure gels are made of and what they do in the body.  One of the many eye-opening things I’ve learned is that the difference between complex and simple carbohydrates only refers to how heavy the molecule is, not how fast the carb hits the bloodstream.  Small molecules are simple and big molecules are complex.  But as Savage writes, “This division into simple and complex is unfortunately crap (biochemistry term meaning ‘not useful’).”  So simple carbs like fructose have a low glycemic index and are slow to digest while maltodextrin digests quickly.  And it’s even faster than pure glucose.

But speed of digestion is only part of the story.  Ever wondered why every commercial gel pack instructs you to drink water with it?  That’s because in order to process the carbohydrate, your body needs a certain amount of water and each type of carb requires a different amount.  Maltodextrin requires six times less water than glucose and frutose!

This is the part that convinced me to try it.

Why does the amount of water matter?  Obviously you are going to be drinking fluids during a marathon, so is this really even an issue?  YES!  A gel with 20 grams of maltodextrin (and nothing else) requires 2.2 ounces of water to become isotonic (fancy word for becoming the same concentration as your blood and therefore absorbable) and a gel made with fructose or glucose needs a whopping 12.8 ounces!  If you take 2 gels an hour, you’ll need to fill your stomach with 2 and a half pints of water, just to absorb the gel. If not, it will just sit in your stomach, probably causing all sorts of gastro issues.  Not to mention that means you need to stop 6 times an hour at water stations and drink the entire 4 ounce cup without spilling.  Yeah, right.

So why do I add fructose at all?  Since there are different pathways in the body to metabolize fructose, adding a little to either maltodextrin or glucose allows you to absorb more calories of carb per hour than either carb alone.  More calories per hour means more energy!  I’m willing to trade drinking a little extra water for more calories.

So where do you get maltodextrin?  You can buy an 8-pound tub on Amazon, which would make about 181 gels for $23.  I chose to go to my local homebrew supply store and buy 8 ounces for $1.50, just to be sure I liked it.  It works out to be about the same per pound, so I’ll support local.

Enough science!  Here’s the recipe for chocolate. Sub a teaspoon of lemon or lime juice for the vanilla and cocoa for a citrus flavor.  For peanut butter, swap the cocoa for 2 teaspoons of peanut butter powder like PB Fit.

Chocolate Copycat GU Gel

Create your own chocolate race fuel!

  • 20 grams maltodextrin ((8 teaspoons))
  • 7.5 grams agave ((1.5 teaspoons))
  • 1/32 tsp salt
  • 1/8 tsp vanilla
  • 1/4 tsp cocoa powder
  • 2 tsp water
  • 1/32 tsp Morton's Lite Salt
  1. Mix all ingredients in a small bowl until smooth

  2. Pour into a gel flask or custom-made FoodSaver bag

146mg sodium

87.5mg potassium

28g carbohydrate

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34 Responses

  1. Have you tried the Stinger gels... they are based (somewhat I'm sure) on honey. There's a massive honey taste to them. And while I don't fully dig them, they are a good change of pace from the typical gels/gatorade taste.
    • I'm not a big fan of honey, so no, I haven't tried them. Honey is a mix of fructose and sucrose, so not the absolute best choice based on absorbtion rates, but if it works, great! I posted about my Honey Stinger Waffle fail earlier this summer. It wasn't pretty!
    • I am excited to try my hand at making these. Do you think tapioca maltodextrin would work? And how about leaving the agave out altogether? Thank you!
  2. Hi Claire! Somehow followed your recipe but modified for my taste and needs. First marathon completed without any damage or bonking... except some cramping of course :) I used a mixture of maltodextrin, fructose and sea buckthorn juice. Exactly I mixed 150grams of maltodextrin, 25 grams of fructose and around 75 grams of buckthorn juice. I obtained around 250 grams of thick gel I stored in a 250 gram Salomon Soft Flask ( Of course I drank water on the course to dilute the gel and also put water in the flask as I consumed the gel. I finished full of charge. The buckthorn juice concentrate is very sour but adding fructose you can adjust the sweetness to your taste. And is full of vitamin C and other goodies. Thank you once again for sharing good things with us!
    • So glad you tried it and it worked out! I have never heard of buckthorn juice. I'm going to have to look into it! I haven't decided yet if I will put my gels into individual Food Saver bags or use my gel flask. My worry is that the hard sided gel flasks don't squeeze much so you are left with gel inside. Your idea of refilling with more water is a good one. I don't know if I'm coordinated to do that at top speed though!
      • :) The Salomon flask is so soft it sqeeze out every bit of gel even if is thick. Thanks to the bite valve it remain vacuumed. I made it thick, very concentrated (not isotonic) just to be sure I have enough spare calories with me. I think I packed around 600 calories :D I screwed with the electrolytes hence the crampings... The Salomon flask can be rolled and put into a pocket because is so soft and flexible. I think the main advantage of such soft flasks is one can sip a little bit of gel to allow it to be digested and for a constant supply of energy.
    • Hi Robert! This recipe is for a single gel. I usually make my own gel packs in a FoodSaver, but you can also use a gel flask. Let me know if you try it!
  3. Thanks Claire, I am going to give this a go. The water after the gel now makes sense. You cannot drink that much! And, now I know what those floppy bottle type thingies are !.
  4. I think that somewhere on your site in the past I have come across an electrolyte recipe that is similar to mine. Now looking at your gel recipe, why not just throw the maltodextrin into the electrolyte mixture? Thinking for my size I would need about 6 tbsp an hour, throw that into 16 ox of electrolyte mix and just have the one item.
  5. Hey Claire! This is such great info. Do the girls need to be refrigerated if you use the food saver bags? Do you know how long they last attoon temp? Thanks!
    • I freeze them just to be safe, but they probably don't need it if the ingredients themselves don't need refrigeration.
  6. Thanks and apologies for all my previous typos :) Last q: which food saver model do you use in order to make the small gel packs? Do you use a roll and then cut to size, then as you mentioned seal on 3 sides, fill and seal the 4th? I'm having trouble figuring out how to seal the 4th side without the gel seeping out. Thank you!!
    • I'm not sure the model number, but yes, I use the Food Saver Rolls. I make the bags long and fairly skinny and only fill them about 60-70% full. Then I squish the liquid down as far as I can and seal the fourth side. Occasionally a little seeps out, but with a little practice, you should get the hang of it!
  7. Hi Claire, Thank you for the recipe and commentary! What do you think about substituting dextrose for maltodextrin? Thanks!
  8. Slight correction, the regular and lite salt should be 1/16th of a teaspoon. The regular and light salt nutrition labels are measured at 1/4tsp for a 1.5g and 1.4g serving respectively, so 1/16tsp of each will give you the correct 375mg and 350mg values that you posted above. That being said, this is seriously the best recipe and nutrition explanation I've found! I've used it on a couple long runs so far and have had no gastro issues. It tastes like chocolate syrup sooo good :)
  9. Is the website experiencing technical difficulties? In the section where the recipe is supposed to be displayed it just says: [mpprecipe-recipe:11] I look at other recipes and saw a similar message. These recipes look great and I'm excited to try them.
    • Hi Steve! Thanks for letting me know. Yes, my recipe plug in is being updated and it looks like I've got a lot of work to do! This one is fixed. Please let me know if you have any questions!
  10. Thanks for the recipes and comments from others. I will certainly give this a try, store bought gels are too pricey
  11. Claire do you mind sharing which you found to be more effective for marathon distance, these gels or the DIY UCAN? They seem to be two different approaches with the gel aiming to fast release as many calories as possible and the UCAN to slow release steadily after quickly emptying from stomach. Do you prefer one strategy over the other or do you use both in the same run?
    • Hi Lani! Great question. For me, the DIY UCAN is the best fuel for the marathon for my stomach. The downside is that it's bulky to carry all that liquid. So a hybrid strategy is to go for as long as you can on the starch, then supplement with gels near the end of the race. Although again, for me, late in the race is the most sensitive time for my stomach so it can be tough to ingest any kind of gel at that point. Some people will make gels out of the starch (just use less liquid) which makes it more portable. Hope that helps!

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