Starches vs Maltodextrin/oats


hello my fellow DIYers. long time no see.
i wonder if anyone here uses a combination starches with oat flour instead of maltodextrin?

or using starch(as cornstarch) as it’s main carb source to lower the use of Oats?


Hey! Good to see a DIY thread again. :slight_smile: I use oat flour and tapioca flour half and half in Schmoylent. You can also use rice flour (cheaper than tapioca flour) but it’s gritty.


I don’t see the point of subbing starch in for maltodextrin. You’re just bringing in one fast glucose source for another, while making texture and mixing worse.

If you’re going to replace the maltodextrin, go for something different. Starch had every down side of maltodextrin and then some (except for sounding safer because it’s “natural” and has a traditional name.)


i take it the DIY threads have slowed down over the years :/.
hows the taste and feel of tapioca/oat divide compared to normal oat dominated recipe?

as i mostly is interested in corn starch or potato starch as it’s cheaper and low in nutritions


@MentalNomad, I find that maltodextrin gives me carb crashes and other sugar-related side effects (I’m particularly sensitive) while the same amount of starch doesn’t. Maltodextrin is starch that is partially converted to sugar, so it’s not necessarily equivalent.

@Myarter Recipes with 100% oat flour taste kind of like oatmeal. Replacing 50% of that with starch makes the taste more like pancake batter.

Corn starch is a decent choice (basically maltodextrin before it’s partially cooked down to sugar). Potato starch (raw) is not very digestible, so only good in moderation as a prebiotic.


I made exactly one shake with Argo corn starch and found it absolutely repulsive. That said it also had soy flour in it which is another repulsive ingredient. There is definitely a learning curve to diy but I think that people are gathering more and more evidence about what is working and what isn’t.


No offense, but be very careful drawing such conclusions from individual subjective experiments, and be very careful about which starch you’re using. Many commonly available starches and starch products will have a GI very, very similar to most maltodextrins and to simple dextrose (glucose.)

Yes, maltodextrin is starch partially processed via enzymes towards dextrose, a simple sugar (dextrose is the predominant form of glucose found in foods)… but it’s only taken about 15% of the way from starch to sugar. It’s still mostly starch. I think it’s a mistake to think of it more like sugar than starch. It doesn’t make it notably sweeter, and doesn’t necessarily change the glycemic index much (depends on the hydrolysis method and the glycemic index of the source starch.) But even if you pick out a dramatic difference - like comparing a common corn starch with a GI of 85 to a particular maltodextrin at 100, your still talking about two high-GI substances. For that matter, you note “sugar-related side effects…” while I appreciate that you have a sensitivity to deal with, table sugar (sucrose) actualy has a GI of 65, which is much lower than the corn starch you’re talking about. I wouldn’t be too confident that going from a 95 GI to an 85 GI with the same underlying structure solves a problem that shows up with a 65 GI product. I’m not saying you’re wrong about what you’re experiencing, I’m just saying it’s a good idea to be wary of any quick conclusion, because this is a hazy and confusing area.

And each of these - starch, maltodextrin, or even sugar - is still just one component of your soylent. When blended with the other ingredients, I suspect you’re looking a net GI difference which is very, very small.

Moreover, if your corn starch is, say, waxy maize cornstarch, it will have a GI more like 100, anyway! Same for most modified corn starches. To get the 85 GI, you need common cornstarch.

And I don’t recommend potato starch at all. If you use potato flour as your starch, to make it digestible, you can mix the starch with water and then heat it so it will gelatinize (you don’t need to boil it to cook it, but the faster you heat it, the higher you need to take the temperature before it gelatinizes - 75 degrees C or 167 degrees F will definitely do the trick, even if heated very quickly.) The downside here is that potato starch has a GI of 95, anyway - so you might as well use maltodextrin, which doesn’t require any cooking to be digestible!

But there are other considerations, too, which are likely the reason Soylent is made with maltodextrin.

Firstly, maltodextrin dissolves in cold water very quickly and does so more easily than corn starch. Corn starch takes more time to “absorb” water and for the starch molecules to fully hydrate. If you always make your mix ahead of time and soak, it’s fine, but I often mix and drink my first glass right away. I’m fairly sure Soylent is designed so that people who want to can do this, even with icewater.

Secondly, corn starch can have a substantial thickening effect. That’s a very common use of cornstarch in cooking, in fact - as a thickener for sauces and such. A lot of people complain about a drink that’s too thick! Personally, I like a thick drink… but I also like to include a good dose of fiber. If you use a healthy dose of fiber plus cornstarch, it may be very thick, indeed. I use maltodextrin in my soylent, but I also use a lot of oat flour and other fiber sources, so my soylent is very, very thick - and if I made it with cornstarch instead of maltodextrin, it would be even thicker (too thick I think).

Personally, as I wear down my maltodextrin supply, I may play with blending in or substituting with isomaltulose, which has a dramatically lower GI. Unlike maltodextrin and starch, it acts as a sweetener, but I sweeten my soylent, anyway, so I don’t mind (I’ll just cut back the stevia.)