Mixing a a couple of scoops of maltodexterin and water gives you an excellent source of on-the-go energy. The combination is cheap, highly portable and has neutral taste. Nutritionally, it's dead simple as it's nothing more than quick absorbing carbs and hydration.
I got to wondering: could I replicate this profile but with slow absorbing carbs? This would make for a drink that was useful for less intense activities, like a day of hiking or traipsing through the outlet mall.
I'm not entirely sure where I got the idea, but I eventually found myself on Amazon searching for Oat Powder. The idea being that oatmeal has the slow-carb nutrition profile I'm after. Sure enough, Oat Powder is a thing and the reviews were encouraging. Here's a sample:
I rode the D2R2 180km route using whole oat powder + Nuun in my water bottles. Here are the positives and negatives
Positives:
It did the job and I felt great consuming about 40gm of carbs per hour via oat powder. Carbs were diluted to 5-6%. I was able to keep my stops short because I would just refill my bottles, eat part of a banana, and go.
It's super cheap. It costs about $0.50 vs perhaps $5 for 40gm of carbs from energy bars.
It's complex carbs. I didn't have any highs or lows. I could just have a gulp of water every 5 minutes and I was getting the right amount of water and carbs.
Negatives:
It's messy. I used condiment containers to hold the oats, which was great for portioning, but a bit messy to get into the bottle. I need to find a better way to transfer the right amount into a bottle.
I had to shake my bottle before every drink. It doesn't mix evenly for very long.
If you don't like oats, well, don't even try this. I didn't find it to be as gross as it sounds, really, but you do taste oats in liquid form.
Inspired by the reviews, I grabbed some generic rolled oats from our pantry and scooped them into our blender. I pressed the blend button for 30 seconds, and just like that, I had oat powder. I scooped it into a water bottle and gave it a good shake. Appearance wise, it looked nasty. Taste wise, is was essentially neutral, with a hint of oats (no surprise there). I found that shaking the bottle between swigs helped distribute the bits of oats. Cleanup wise, refilling the bottle and drinking the remaining oats left my water bottle debris free.
By the time I finished drinking my first batch of powdered oats I was hooked. This stuff is awesome.
Since my early experiments, I've refined the process. I grind a bunch of oats ahead of time and store them in a big 'ol Ziploc bag. I find the larger cap size of a Bodyarmor sports drink to be more convenient for mixingthan a standard disposable water bottle. The spout end of a soda bottle makes for a perfect funnel, and at home I'll use this to make preparing a bottle of oat energy drink mess free. When on the go, I cut off a corner of the Ziploc bag that stores the oats and use that as an improvised funnel.
So how closely did I come to my original goal?
Cost - powdered oats, if you can take a few minutes and grind them at home, are beyond inexpensive.
Portable - 40 grams of powdered oatmeal stores nicely in a snack size Ziploc and takes up minimal space. The powder doesn't melt or get impacted by the heat. You can mix up a batch in a few seconds, either at home or in the field. I've mixed, shaked and consumed immediately and I've waited hours before drinking; either way works.
Taste - Oats and water makes for a crude version of oatmilk. What little taste it has is quite palatable.
Nutrition - 40 grams of oat powder has 27 grams of slow-release carbs, no sugar and even a bit of protein and fat to round it out. Oatmeal is a proven source of slow energy, so you're getting the benefit of a high quality food without sketchy add-ons. Finally, you get the bonus of hydration due to this being a drink-based mixture.
For a slow source of carbs, powdered oats is hard to beat. I'm surprised it's not more of a thing. My new favorite on-the-go meals is to combine the oats with a protein bar and a fruit strip:
I get slow-carbs and hydration from the oats, protein from the bar and quick energy from the fruit snack. The bar also contains sugar and fat, which makes the whole meal more tasty. The meal fits in a sandwich sized Ziploc and can be easily consumed on on the go.