The Story of DirtBags
Every year, millions of single-use energy gels, energy powder sachets, and plastic zip bags are torn open on trails and mountains, only to end up in landfill, or worse, left behind in nature.
DirtBags are the first, ultralight, reusable and compostable zip bags designed to organise and carry your fuel and essential items for long days out on the trail that directly replace single-use packets and plastic ziploc bags that all end up in the landfill.
The Essential Summary
Use them, wash them, and reuse. When they're done, they simply return to the earth. It's that easy!
- DirtBags save you money - Buy nutrition in bulk or make your own fuel at home
- DirtBags are double zip resealable bags that can hold fuel and gear.
- DirtBags are ultralight, weighing less than energy gel packets.
- DirtBags are reusable, wash your empty DirtBags, air dry and reuse again and again
- DirtBags are compostable a circular life cycle
- DirtBags create less CO2e compared to single-use gel packets or plastic zip bags
- DirtBags offer precise carb amounts for your unique fuelling strategy
If you want a quick intro to exactly what DirtBags are, watch this 3 minute intro below.
Small DirtBag 14 × 6 cm – Small, sized just like a large energy-gel and built for fuel on the move. Perfect for refilling with bulk bought energy gels, powders, chews, home-made energy bars and you get very specific portion control so you know exactly how many carbs you're getting each time you fuel from one.
Large DirtBag 16 x 18 cm – Larger and versatile. The perfect size to fit in your hydration vest or pockets. They're great for carrying a full day’s worth of energy powder, bigger snacks, or keeping items like your phone, socks, first aid kit, toilet roll or keys dry and secure as well as putting your empty small DirtBags in to reuse on your next adventure.
After hundreds of different size testing and prototypes these two have come out as the best all-rounders that fit perfectly in pockets, waist belts, hydration vests and backpacks.
💡 The Idea
The idea was simple, create reusable bag that can hold a gel, I can consume my carbs from and then reuse again after cleaning. As well as replacing larger plastic zip bags that would fit perfectly in my running gear pockets and bags and hold more fuel options or my small essentials in an organised manner.
Small DirtBag (14 x 6cm)
In the small DirtBag's you can refill with your own home-made energy gels and bulk bought energy-gels from brands. As well as energy powder, energy chews, energy bars, sweets and many more fuel options. Each one can be weighed so that you have precise carbohydrate control and amounts in each small DirtBag for your fuelling strategy.
You can also carry small items that you may want to keep dry or organised, like camera batteries, keys or talc for your feet.
Things You Can Carry in a Small DirtBag
- Energy powders
- DIY or bought gels in bulk
- Nut butters
- Sweets
- Salt tabs
- Keys
- Camera batteries
- Sd cards
- and much more!
Large DirtBag (16 x 18cm)
We often buy snacks and sweets from supermarkets but the packets they come in are often too big or the wrong shape to hold the food once they've been opened.
With the large DirtBag you can carry snacks like waffles, biscuits, sweets, trail mix and home-made energy bars and chews. I often decant biscuits and stroopwaffles I have bought in to large DirtBags for continuous snacking. If you just fuel from energy powders then you can place multiple servings and hours worth of energy in to one large DirtBag, which you can use to decant in to your bottles throughout the day.
As well as fuel options, the large DirtBag is great for carrying essential items you need for your adventures, like a phone.
Things You Can Carry in a Large DirtBag
- Trail mix
- DIY energy bars and chews
- Socks
- Biscuits
- Gloves
- Sweets
- Phone
- Toilet roll
- Waste & used bags
- Fruit skins (like banana skins)
- A lovely sandwich
- and much more!
The great thing about DirtBags is that as well as precise fuel control, you can organise your kit in to large DirtBags so you know exactly where specific pieces of gear are and know they're secure and dry whilst keeping to an ultralight philosophy.
Precise Fuelling With DirtBags
During my last 100km mountain ultra, I filled two 500ml silicone soft flasks with energy gels but ran out early because I couldn't track how much I was consuming. I was taking a guess every time I swallowed the gel from the soft flask and ran out of the 1L of gels hours before I had planned to.
Silicone soft flasks are amazing to use for your water, hydration and when used with energy powders, but they still have their issues.
- You can't do precise fuelling if you use them with energy gels inside
- You can't carry chews or home-made bars in them
- They are much heavier to use than DirtBags
- They have a much larger impact on the planet to produce
- They cannot be recycled
Single-use gel packets work well precisely because you know exactly what you've consumed. If it says there are 40g of carbs in the gel and you consume the contents of that single-use packet, you will have taken in 40g of carbs.
You get the exact same convenience and precision with DirtBags.
The key advantage is precise portion control, if you're targeting 80g carbs per hour, you can pack exactly 40g of carbs in a small DirtBag using the fuel of your choice, or customize portions to match your specific fueling strategy, whether you're aiming for 60g of carbs an hour, 90g or even 120g of carbs per hour.
As part of this project, we're also creating a list of nutrition brands that sell energy gels and powders in bulk at For The Trail.
In the image further above you can see this done with 40g of energy chews, 45g of powder and 35g of energy gel, resulting in 120g of carbs if you were to consume them all.
Above I am consuming a bulk bought energy gel I put in to a small DirtBag, it has 30g of carbs in it and two of these an hour will keep me on track for a 60g/ph carbohydrate fuelling plan. Convenient to get out of my hydration vest, consume the energy gel, close and pack away the empty in to a large DirtBag to later clean and reuse.
The same applies to powders, energy chews, energy bars, sweets, or DIY bars, simply decant exact amounts into each small DirtBag before your adventure and consume every X minutes to stay ahead of your fuelling strategy.
You can also fill the large DirtBags with your fuel of choice to cover you for longer adventures. You can carry a full day's energy powder of 6+ hours in a large DirtBag, just decant in to your soft flasks using a small scoop or pouring it in with water every few hours.
You get the convenience and precision fuelling you want for training and racing as well as being able to take them home, wash them and reuse them on your next adventure.
🚨 Single-use Energy Gels & Packaging Pollution
When compared to single-use energy gels and single energy powder sachets, DirtBags deliver significant environmental benefits. Each small DirtBag is lighter than the average gel packet, requiring fewer resources to manufacture and have a smaller climate impact too!
But the real environmental advantage comes from re-usability.
Single-use gel packets and powder sachets create ongoing waste. After one use, energy gel packets, single powder sachets, other plastic wrappers and plastic zip bags eventually end up in landfill where they persist for decades and even centuries.
I’ve carried them myself for years during trail runs, hikes, and ultra-marathons. They’re convenient in the moment but always destined for the bin. Plastic gear like this doesn’t belong on our trails.
Outdoor gear should protect nature, not harm it. But right now, our fueling systems and storage solutions are some of the worst offenders. And at the heart of it all: single-use energy gels and plastic packaging.
Silicone soft flasks are much better alternatives for carrying our fuelling requirements for big adventures and can be reused many times, but they still have their environmental issues.
- They ask far more of the planet in their production
- Hard to recycle, here in the UK they are categorised as "non-recyclable plastic"
There are much bigger demands on the planet to produce silicone, they still use plastic caps on top and have much larger carbon emissions in their production. You will have to use a silicone soft flask hundreds of times before it's climate impact comes close to a DirtBag.
While silicone can technically be recycled, specialized facilities are rarely available, meaning most silicone flasks end up in landfills and they will persist in landfills indefinitely as they cannot be broken down by natural organisms, unlike truly biodegradable materials.
🌍 Solution
DirtBags are ultralight, reusable and compostable zip bags designed for adventure.
Reduce > Reuse > Recycle
The industry has led us to believe that recycling and recycled materials are the holy grail of sustainability, when in fact, it's the last thing we should be doing, our focus should be on reduction and reuse first.
DirtBags reduce the climate impact, carbon emissions and environmental footprint compared to single-use gel packets and plastic zip bags.
DirtBags are reusable over and over again, simply use, wash, air dry, use again.
Materials
DirtBags are crafted from PBAT (polybutylene adipate terephthalate) and combined with PLA, which is derived from plant sources, this blend significantly cuts overall fossil fuel use and makes compostable.
These materials provide viable alternatives through renewable and bio-based plastics that help curb waste and reduce our reliance on fossil fuels.
Bioplastics are made by extracting cornstarch from corn kernels, then heating and mixing it with ingredients like vinegar and glycerin to create a polymer. The vinegar acts to break down the starch molecules, while glycerin acts as a plasticizer, making the final material more flexible.
This mixture is heated until it solidifies into a plastic material and we get the base granules shown below which are then used to make a myriad of bioplastic products, in this case, DirtBags.
Most importantly, they facilitate the transition toward a more circular production system where materials can return to natural cycles rather than accumulating as permanent waste. Which is the case for gel packets, plastic zip bags and silicone soft flasks.
Climate Impact
A single DirtBag used just once already cuts the footprint of a single-use gel or plastic zip bag by ~60–95%.
This is due to the multiple layers of plastic in an energy gel packet, that it weighs more (requires more energy to create), goes in to landfill at the end of its single use and is made entirely out of fossil fuels.
If you use a DirtBag 5+ times, you’ll cut the carbon footprint of single-gel by almost 99%.
Using a DirtBag Just Once - Worst Case Scenario
Even if you used a DirtBag just once and threw it away, just like an energy-gel, you would still have a smaller climate impact if choosing the DirtBag.
As well as reducing their impact on the planet with just one use, they are also reusable, so their impact gets smaller and smaller each time you reuse them.
There are many environmental positives to choosing DirtBags, here are some of them:
- DirtBags have a 45-95% smaller climate impact in their production compared to a single-use energy gel packet or plastic zip bag
- By switching to bulk fuel that you decant into DirtBags, you reduce packaging waste by up to 60% when comparing to using single-use plastics gel packets & wrappers
- DirtBags have an even smaller climate impact compared to silicone soft-flasks which aren't even recyclable
- DirtBags are made with plants from a single material instead of multi-layer laminated plastics like gels and powder packets
- They weigh less than the average large energy gel packet which means even smaller impact on the planet when comparing gram for gram
At the end of their life you have the option to compost them as they are made of bioplastic that are designed to break down much quicker than normal plastics into water, CO2 and biomass.
So you've saved on extra virgin plastic being created, you've created less emissions and you're stopping plastics from entering the landfill.
As well as asking less of the planet in its production, DirtBags are made of bioplastics.
Unlike conventional plastics that fragment into harmful microplastics, compostable materials return safely to the earth.
"One of the main advantages of PLA and PBAT is their biodegradability. Unlike traditional plastics that can take hundreds of years to decompose, PLA and PBAT can break down into natural compounds within a few months to a few years, depending on the conditions. This makes them a more sustainable alternative to conventional plastics, which contribute to the growing problem of plastic pollution in the environment."
"In terms of environmental impact, both PLA and PBAT have been shown to have a lower carbon footprint compared to conventional plastics such as polyethylene and polypropylene."
We have been composting our prototypes for over a year and will have a guide on how you can do this on For The Trail.
✂️ Bringing DirtBags to Life
It all started with the issue of replacing single-use energy gel packets and ziplock bags that both would be carried for long adventures and endurance feats.
Here are just some of the questions I wrote down in 2024, the DirtBags had to work in real life scenarios and answer many different questions.
- What are the average serving sizes of gels, powders and chews
- How many grams of carbs can different sizes hold
- How easy are they to use
- To open and close
- Put in mouth to use with gels
- Decant powder in to bottles
- To get chews and energy bars in and out
- Easy to get in to waist belts, pockets and hydration vests
Here are some of the early designs I did, going from single zip reseal to two zips for extra security, changing widths and lengths and I even added a tear option to an early prototype which I soon removed from the designs.
This is where it all started and where it has finished, instead of being single-use, the requirement for them to be reusable and have a circular life cycle and to carry a large energy gel serving that was secure, would carry at least 30 minutes of carbs, would fit in any pocket, could put it in your mouth and consume a gel easily whilst being able to decant energy powder in to bottles, carry other fuel options and small essentials and could be taken home, washed and reused.
I have made a myriad of sizes for dirtbags to find the perfect two sizes for precision fuelling, which would become the small DirtBag and a large DirtBag that was big enough for a phone, some essentials whilst being able to fit in any pocket.
Over the last 12+ months these are just some of the size examples I had gone through. Many prototypes covering different size ideas for a small and large DirtBag.
On the left you can see two large DirtBag prototypes.
- Top left is 16x16cm which would be too narrow for most phones but was a good height at 16cm.
- Bottom left is 14x18cm, this was too short but became a good width for most phones and other essentials we carry on adventures, including a sandwich too!
There are then many small DirtBag prototypes on the right which were tested, some, like the 12x6cm, middle center, I would test with for over a year, you can see it in the next photo too where I used it to carry a spare battery and SD card.
The other sizes that were tested over the span of many months and covering many different fuelling scenarios.
- 10x5cm - This was too short and too narrow after testing with various fuel options and essentials. I couldn't get much more than 20g of carbs in powder form.
- 12x5cm - Again, felt slightly too short and was still too narrow but was an improvement.
- 14x5cm - Getting closer and for a month or so thought I was on to a winner.
- 16x6cm - Tested this size specifically for energy powders to hold over an hours worth in one bag, would later be too big to work in combination with the large.
- 12x6cm - The testing and prototypes were definitely getting closer, I ended up using this for a few months fuelling but found it was hard to get 30+ mins of energy in gel form. I could make it longer as it always felt small in my pockets.
- 16x8cm another small DirtBag but was just too big and bulky to be used on its own, hard to manage when gel was put in it and then struggled combining it with a large.
The above prototype I have used in my bumbag or shorts pockets with a spare camera battery and spare SD card in it for almost a years worth of testing sizes. It lasted approximately 10 months of continuous use before it started to get a couple of small holes in it. I was using it every week for my training when running with my camera and on a handful of trail and ultra-marathon documentaries where it performed remarkably well in all conditions and meant my spare was protected and ready when I needed it, which was a lot!
Testing With Energy Gels, Powders and Chews
I made 30g of carbs a minimum to hold, as those aiming for 60g of carbs per hour (which is recommended) would only have to use 2 small DirtBag servings per hour. I also found out averages of energy gel, powder and chew sizes.
I found the 14x6cm sizing perfect for decanting energy powders in to, placing in a pocket without being too small or big, would hold upwards of 40g+ of carbs and easy to pour in to your silicone soft flask, it was ticking all the boxes.
Some of the testing of energy powder use in various small DirtBag prototypes. There was a lot of testing done for how many carbs they could hold, did they meet my minimum requirements, how easy to add the energy powder in to the DirtBag and easy to get it from the DirtBag in to your soft silicone flask when out on an adventure.
You fill up your small or large DirtBags with your energy powder of choice and then carry with you for your adventure. Simply add water and your exact serving of powder to you silicone soft flask in just a few seconds.
I found the 14x6cm small DirtBag perfect for energy gels, chews, home made snacks and energy powder. There were quite a few issues with different sizes, they may have been great for one specific task or requirement, then fail at others.
The DirtBags had to be great at a myriad of tasks and requirements.
Here I have noted that the 5cm width small DirtBag zips that sealed them would fail earlier than other larger widths because of how narrow they were. They still worked for a good few uses but not last as long as larger width DirtBags and I found out this was mainly due to cleaning them and drying them and when left to dry they would be left open and the zip seal would bend and stay bent open and make it harder to seal and close.
🌱 Summary and Why DirtBags Matter
Planet-friendly materials — Made from corn starch-based bioplastics (PLA + PBAT). You wash and re-use them as many times as you can. We will post them in recycled cardboard envelopes with an eco information card. Everything that you receive, including the DirtBags themselves is compostable for a fully circular life cycle.
Smaller Impact — They create less CO2e compared to single-use gel packets or plastic zip bags in their production. You could use them just once and still be better for the planet! We recommend using them as many times as you can though.
Built for longevity — Thicker than standard zip bags and double-sealed with two zips for extra life. So if one of the zips fail, you can still use them to store your gear and fuel.
Versatile — Fill the small DirtBags with gels, powders and snacks where you can do specific portion control. Large DirtBags are great for carrying a first-aid kit, toilet roll, your mobile phone, and will keep other small essentials dry and organised.
Ultralight - DirtBags weigh much less than single-use gels and silicone soft flasks which means you will have a reduced pack weight, perfect for those interested in ultralight.
Save you money - As well as saving rubbish destined for the landfill, you should also save money as you can buy in bulk. Gels, powders or even make your fuel at home will cost less.
Use them. Wash them. Reuse them. When they’re done, they go back to the earth.
👣 Join The Movement FOR THE TRAIL
For The Trail is about demanding less from the planet, through radical, durable solutions that put the environment and biodiversity first.
Join the circle — learn about nature, share what you know, and help protect the trails.