Barley Malt Extract


Maltodextrin has a high glycemic index. Most place list it as 105, though one website said there are different forms of maltodextrin and they range from 85 to 105. Nonetheless, both numbers are high. Even sucrose has a lower GI, at 64. I realize that soylent itself will have a lower GI, since it includes fiber and oil, but still, a sucrose soylent would have a lower GI than a maltodextrin one. Sucrose is also cheaper.

The upside with carbs like sucrose and maltodextrin is that they don’t need to be cooked, soaked, sprouted or sour fermented to mitigate phytic acid and make them more digestible. But the downside with sucrose is it’s too sweet. Some sweetener in soylent isn’t too bad, but not in the quantities most of us are using maltodextrin.

So, I was looking for other carb sources that would have a lower glycemic and not as much sweetness. Brown Rice syrup looks good. It has a GI of 25 and is only half as sweet as sugar. Unfortunately, there was a report last year that brown rice syrup contains relatively high levels of arsenic, which would be a concern at the levels we’d be eating it at.

Barley malt extract also looks attractive. It’s also about half the sweetness of sucrose, and has a modest GI of around 42. It can be purchased as powders from beer-making suppliers, and in different flavors: amber, dark, pilsen, wheat. It is a bit more expensive, about twice the cost of maltodextrin per calorie. The Now Carbo Gain goes for $33.57 (shipping included) for 12 pounds at, which works out to 0.16 cents/calorie. 12 pounds of malt extract from, would set you back $40.06 (shipping included), which works out to about 0.3 cents per calorie. Thus, if you’re getting 500 calories/day from maltodextrin, that’d raise your cost 70 cents/day

Admittedly, I don’t know anything about the taste, and for all I know it still might be too sweet or have a strong aftertaste. Any other thoughts?


Good work,Joseph. This looks like a promising direction for further investigation. I’ve wanted to try out barley malt extract and/or syrup but at the moment don’t have the resources to do so. It’s a shame about the brown rice syrup but you’re right – there is a lot of concern about arsenic in rice products these days and until/unless that gets resolved reliance on a rice product in quantity would be unadvisable.


My immediate concern is gluten. A site with information on coeliac disease has this to say about barley malt extract:

Food products high in barley malt, such as malted drinks, are not suitable for people with coeliac disease.

Our Soylent mixes would be very high in barley malt if we used it.

The carbohydrate source a few other people have mentioned is palatinose. Palatinose has a much lower glycemic index than maltodextrin. It’s usually stated as around 32.

I can’t find a reliable source stating that palatinose gluten free, but I also can’t find anything linking it with gluten. One rather angry forum poster insists that it’s gluten free unless it has been contaminated with wheat products during manufacture and storage; similar to oats.


Palatinose sounds good. According to the company’s faq (, it has half the sweetness of sucrose. It’s worth trying out.

Also, it would seem unlikely that palatinose would contain gluten since it’s derived from food grade sucrose from beet sugar.

Price is not bad either. 5kg from ( is $33.49, which works out to 0.18 cents/calorie. On the other hand, shipping is expensive from them, since they ship all the way from UK, $34.99 flat rate for large orders. Know of any good sources for it in the US?


Beat me to it.

For those of you without celiac/gluten issues, sounds like it might be a good substitute.

However, I’m not completely sold on the whole GI thing. But that’s just my personal opinion, I haven’t seen much if any real research on it.


What about Waxy Maize Starch? Some interesting data on absorbtion rates and insulin response compared to malto and dextrose:


Here’s some research on the benefits of low Glycemic Index diet. There’s room for skepticism, but the evidence seems pretty strong.

This article ( surveys a number of different studies on low-GI diets. It notes that there’s good evidence that low-GI diets reduce risk of Cardiovascular disease, Coronary Heart Disease, Age-related Macular degeneration and cataracts. I should add that some of the studies on CVD and CHD looked at GI, some looked at GL (glycemic load). GL is the product of both quantity of carbs consumed and GI.

Some evidence shows low-GI diets reduce risk of type-2 diabetes. This trial showed that a low GI diet over six months reduced the average blood sugar level and decreased HDL concentrations in patients with Type-2 diabetes : This one showed that rats fed a high-GI diet tended to have a higher body fat percentage and lower glucose tolerance: In the article linked to above, it said 7 out of 12 studies showed a negative correlation between the GI of a diet and risk of type-2 diabetes.

Some studies even show low-GI diets are preferable for weight loss. This study showed that people who had recently lost weight, who were assigned to a low GI diet were at lower risk of gaining back the weight (based on measuring resting metabolism, or “Resting Energy Expenditure,” as they call it) compared to people on a high GI diet:
It’s worth noting in this study that the people on a high-fat, low-carb diet fared even better, but, based on measure of other proxies for heart disease risk (such as hormone levels, HDL/LDL levels, insulin sensitivity), the authors judged the low-GI, moderate-fat diet to be superior overall.

Some people criticize GI since they think there are better measures, such as Glycemic Load or insulin response. There are some things that GI doesn’t capture. For example, one study showed that the risk of developing type-2 diabetes increases when you consume more fruit juice, but decreases when you consume more whole fruit (, though both have the same GI. Nonetheless, the general consensus is that you should try to avoid fast carbs that cause a dramatic rise in blood sugar and insulin levels, and that you shouldn’t get too many of your calories from carbs. Preferably you should consume a mix of carbs, fats and proteins (though what precise mix of the three, that’s when the gloves come off and the fights get ugly).


You can’t look at the GI of ingredients in soylent in isolation, as the combination will have a much lower GI than malto alone.


Thanks for the info, looks like some good info there.

I concur.

I am personally very aware of my blood sugar levels, as when I was younger I had issues with a near hypo-glycemic type condition. I don’t notice much in the way of serious energy level swings that I usually get by heavy ups and downs with my blood sugar, which leads me to believe that my soylent is being absorbed reasonably slowly.


The point with maltodextrin is that if we use a carb source with a lower GI, it’ll lower the GI of the Soylent overall. A maltodextrin-based soylent, which includes includes oil and fiber, will have a lower GI than the maltodextrin alone, but a palintose-based or barley-malt-based soylent will have a lower GI than a maltodextrin-based soylent.


Very true. I am going to start looking into a lower GI alternative to malto, something that is within the same price range and semi-readily available. Too bad I can’t use the barley malt.


@JosephK Joseph, how useful do you reckon the Glycemic Index is to us in actual practice? I took a couple hours yesterday trying to look into it, and found it fraught with disagreements, fuzzy numbers and first-approximation analyses, like so much else in the field of human nutrition. I was looking for a nice clear table of food ingredients with their GIs beside them. Didn’t find it. I discovered some nutritionists try to patch up something they consider unworkable by correlating GI against the gross carb content of given foods and calling it Glycemic Load, but the figures thus generated looked equally approximate and the users seemed most comfortable with grouping the foods into three categories, relatively low, middle and relatively high glycemic load. The actual GI figures seemed to vary all over the map for the same food, “depending” upon numerous variables including who was doing the measuring and how, such that any attempt to compare various foods by GI looked to be constructed on a pretty shaky foundation.

I think they ought to suspend any idea of calling the field of human nutrition a “science” for a few more decades! The more I go into it, the more it looks like witch-doctory to me. :frowning: I am NOT COMFORTABLE with the glib way we talk about things like GI as though it were something that has been thoroughly investigated such that it is reliably quantified with the relative values all nailed down nicely and neatly.


I think the GI index is useful so long as you realize its limitations. I think you’re right that the GI is not a very precise measure. I linked to an article above by a supporter of GI ( who noted that there needs to be more uniformity in how exactly GI is measured, since there are variations in methodology that can affect results. Not to mention that different people have different glucose responses. The GI number they give is based on the average glucose response measured from a small group of volunteers. I think it’s fair to say that any GI measure you read can be regarded as an estimate with a wide margin of error (say +/- 10 to 20 points). But even such an imprecise measure can be useful in giving a good idea of the glycemic impact of different foods.

If you want a good source of GI data, University of Sydney hosts, which is quite comprehensive. also lists Glycemic Loads for all foods. Glycemic load includes both number of calories and glycemix index and thus is not as relevant for us, if we’re creating recipes with a fixed number of carbs. The question of how much carbs vs fats vs protein should be in our soylent is a whole 'nother kettle of fish.

There are alternative measures that might get more at the important facts. For example, there’s the insulin index, which is measured the same as glycemic index, except it looks at insulin levels instead of blood sugar. GI and Insulin Index seem to give very similar results. This author ( measured insulin response with a number of different foods and found that glucose response and insulin response were highly correlated (r=0.70). Nonetheless, for some foods there are large discrepancies. One explanation for the difference may be that the glucose from different foods may be removed at different rates than others, as this experiment showed ( Since the GI is a measure of the blood sugar after consuming a food over a course of time (usually they measure it about every 15 or 20 minutes for 2-3 hours) that means a food that causes blood sugar to spike (causing a high insulin response) then drop quickly will have a lower GI than a food that has an equally high rise at the beginning but trails off more slowly.

For determining how different foods might affect your risk of developing type-2 diabetes, insulin response seems like the measure to look at, and may even be better for determining risk of heart disease. I think measuring insulin response might be a better measure for carbs and maybe for protein and oils, but unfortunately finding info on the insulin response of various foods is much harder than finding the GI; so I’ll use the GI in the absence of better of information. GI is definitely better than just looking at whether a carb is complex or simple.

Also I agree that human nutrition is a very inexact science, but it’s the best data we got; so I guess we’re stuck with it.


I do love your posts, Joseph. You explain things with such clarity.

From my POV (and I doubt that I’m alone in this) where the GI falls down is in its inability to give much of a basis for comparison of various foods, due to the range of values for any given food – when more than a single study exists, that is. It seems like most foods fall into the frustrating mid-range. For example, beets, which are generally esteemed as a rather healthy food, recommended by most dieticians, and so forth, I found listed in’s pages on low-carb diet with a GI of 64 – the same as a Mars bar! I then checked out the Mars Bar’s competitor Snickers – and found it listed at 55! Now that IS frustrating. Potato chips, interestingly, also outdid the beets, sitting alongside the Snickers bar at 51 to 57.

Oatmeal (one of my favourite foods, also esteemed as a “healthy choice”) was as indeterminate in its GI as it also seems to be in its caloric value (which I’ve seen listed so variously that I’ve had to give up on arriving at a definitive value). If it’s “quick” oats, the GI given was 66. Otherwise,“rolled oats” generally (not quick or instant) cooked into oatmeal were rated at – wait for it – 42 to 75 (average 58)!!! It was noted “highest was US oatmeal,” so I’m wondering if Rob’s oat powder expedient is really that much of an improvement on maltodextrin, particularly if the maltodextrin chosen actually has a GI in the vicinity of 85.

I may just give up and scoff a Mars bar – or better still, a Snickers, and call it a “healthy low-GI choice.” And then snicker quietly in my beard when someone (even you, Joseph) learnedly quotes GI numbers for maltodextrin or barley malt extract.

('ll say this for, though – they took some pains to explain the pitfalls of using the GI, right up front in the first page where it wouldn’t be overlooked.)

Hey, one other point, Joseph; you said:

I can’t quite believe you meant to say or to imply that Soylent Corp. is actually going to be doing those things with its oats before they are pulverised – or did you? Do you have any inside knowledge about that? You’re the first person here to come out and actually admit that some fairly extreme processing moves might actually be needed “to mitigate phytic acid” and make those carbs more easily assimilated. So could I ask you this question: what will your opinion be of the final soylent formula if it turns out to include the oat powder, raw and unprocessed except for whatever grinding or hammer-milling technique reduces it from whole oats to powder? Up till now I’ve been feeling a little foolish myself for being concerned about that… what’s your opinion?


i heard that fructose is actually bad for you. i wonder if it might be better to stick to something that doesnt contain fructose, even if it means higher GI


I’m not sure fructose is bad for you considering all fruits contain it. Fructose can be a trigger in some people with IBS though.


IIRC, fructose in refined form is considered less than ideal because it preferentially refills liver glycogen stores before refilling muscle glycogen. This can cause energy level issues for active individuals on a carbohydrate-restricted diet. I think there are other issues too - but I can’t remember the details at this second so won’t spout off about it.

From what I remember, fructose in fruit: good/not bad at worst. Refined fructose added to things: not good, avoid if possible.


I don’t know anything about how they are going to be preparing the oats for the soylent. I just assumed it wasn’t going to be cooked, since Rob said he started using oat powder in his soylent. Oat powder is frequently sold as carbs for bodybuilders, either alone or mixed with other types of carbs. And these carbs are designed to just be mixed into water and drunk. I would definitely prefer if any oats in Soylent Corp Soylent were processed, at minimum to be cooked and preferably to also be either partially sprouted, soaked or sour fermented. To be honest I don’t really know which of these processes are best and how much processing oats needs to go through to reduce the phytic acid to a reasonable amount. When I was talking about GI above I was able to cite studies using scientific procedure and point to reputable sources, but the stuff I’ve found (at least so far) on phytic acid is from less reliable sources; so I don’t know. I do know there is phytic acid in oats and most people say it should be cooked at least.

Then again, Rob, in another post mentioned that they’re looking at other novel sources of carbs; so maybe it won’t have oats at all.

I’m soaking and cooking my oats for my soylent. I should probably mention, since it concerns the other thing you mentioned in your post, that this is probably going to raise the GI for my oats. One of the reasons that there is such variance in measured GI for certain foods is it really can depend on how it’s prepared: how long its cooked, how small are the pieces, how processed it is, etc. Rolled oats will have a lower GI than oat flour because they’re bigger pieces, and quick oats will have a higher GI than rolled oats since they’re more processed. Even just cooking something longer can raise the GI. Two exact same plates of spaghetti — one where the noodles are cooked until soft, one where the noodles are cooked al dente — the soft noodles will have a higher GI. So, with my oats, by processing them and making the nutrients more bioavailable, I’ll probably also make the carbs more bioavailable and presumably raise the GI. But I think it’s worth it.


Thanks for that, Joseph. From the above quotes I am forced to conclude that you think the phytic acid issue is more serious than GI. I have been hanging around the outskirts of the CRON movement and most of those people take GI pretty seriously indeed. I’ve been trying to decide just how seriously to take the phytic acid issue and what lengths to go to, because I eat oatmeal just about every day. Just because the 2010 Ramiel Nagel article “Living with Phytates” was not itself published in Food Chemistry journal doesn’t mean it isn’t a very serious, well-done and rather exhaustive treatment of the topic from a lay-accessibility standpoint. He has done a very thoroughly exploration of the subject and certainly cited some persuasive references from Food Chemistry and elsewhere. I have to take it seriously. The Weston A. Price foundation has done one of the best jobs with their website of any outfit I can think of, about on a par with that of the Linus Pauling Institute, for example. I mean, this isn’t like some of the half-baked vegan BS you see all over the web, all noise and no logic, no proof, no references. I find Nagel’s article most persuasive. What about you?


I wouldn’t say phytic acid is more serious than GI, just that I think the increase in GI from my processing is probably modest and worth the reduction of physic acid.

And I agree. The article you linked to is good. Lots of information with thorough citations. Phytic acid is something to be concerned with when grains represent a large portion of your food, as it does with the oat-based soylent.

Right now what I’m doing with my oats is that they’re mixed with partially-sprouted buckwheat and these together are ground and sour fermented.

If you want the details of how exactly I’m doing it, you can read this paragraph. I take 1 cup of oats and soak them one day. Simultaneously I take a half cup of buckwheat, germinate it in water for 30 minutes (adding some of that water to the oats afterwards) and sprout it for 1 day. Then the oats and buckwheat I mix together in a blender with some water. I then have a big container with two days worth of ground oats and buckwheat. I pour half of this into a pot to make my sour porridge for the day’s soylent. Then I pour in the freshly ground buckwheat and oats to replace what’s been removed, along with two tbsp of sugar. Simultaneously I start soaking of oats and sprouting the buckwheat for the next day’s batch. The porridge I cook for about 10 minutes and it has a sour flavor. Diluting the porridge with some cold water, I mix this with the rest of my soylent (malto, protein, fiber, oil, bunch of other nutrients). The sour flavor is the dominant flavor of my soylent, which I like; so no complaint here.

I hope this process deals with the phytic acid, but preferably I’d like to have a carb source with a much lower GI than maltodextrin but with low amounts or no phytic acid; so I don’t have to do it all.