A lot has changed in the twenty months (has it been that long?!) since I went on my Soylent adventure in 2013, eating nothing but the packages of powdered engineered food product for five days. We weren’t the first outlet to do a multi-day Soylent binge, but as far as I know we were the only outlet to devote so many column inches to talking about how Soylent reacted to our bowels—which, let’s be honest, is what everyone really wanted to know anyway, right?

In the intervening months, Soylent founder Rob Rhinehart has continued to update Soylent’s formula, tweaking the contents and altering the micro- and macronutrient blend in response to user feedback and also actual science and lab-work. The latest change, to "version 1.4," is the most significant since the product’s launch: in addition to ditching the often leaky bottles of oil, the amount of soluble fiber has been greatly reduced, from 10g per pouch to 3.9g; the total amount of fiber has been reduced from 30g to 16g per pouch.

Less fiber seems to go against conventional wisdom, but reducing the bulk of soluble fiber is aimed at cutting down on Soylent’s one truly unfortunate side effect: what we called "horse-killing farts" in our last go-round.

"Some people's gut bacteria are not accustomed to the soluble fiber," Rhinehart explained somewhat laconically when I asked about why all the plants in my house wilted after a few days of Soylent crop dusting.

Taste, texture, portioning

But before we get into the butt stuff, let’s talk a bit about what else has changed with Soylent 1.4 and how the updated meal/drink/slurry tastes—because that’s all different, too.

First off, that old Soylent bugbear, texture. Both the 0.8 prerelease and the 1.0 release version had a texture that could best be described as "silty, like an old riverbed." It was mostly smooth when it first hit the tongue, but the tiny particulate blend of rice would coat the throat and, at least for me, result in needing to keep a glass of water next to my glass of Soylent.

The changed 1.4 Soylent presents a vastly different mouthfeel to both the prerelease Soylent I binged on for five days and also the 1.0 version I drank on and off for most of 2014. When properly blended and chilled overnight, Soylent 1.4 exhibits almost none of the chalky silt that plagued its predecessors. There’s still a hint of "riverbed" after swallowing, but it doesn’t feel like you’re swilling the dregs of a cup of french press coffee anymore.

Also totally changed is the actual taste. Previously, Soylent had a vaguely sweet taste mixed in with hints of bread dough—sort of like a thin pancake batter over which someone had sprinkled artificial sweetener. This Soylent tastes like—very little. There is a much more pronounced umami note—rather than tasting like bread or dirt or sweetness, the new mixture tastes of inoffensive plainness, and it has a presence on the tongue. I haven’t tried mixing it with peanut butter or vanilla or chocolate, but I suspect that Soylent 1.4 will be much more receptive to taking on the tastes of mixed extras than before—the liquid equivalent of tofu.

The bottles of mixed canola and fish oil are also mercifully gone, with Soylent 1.4 now deriving its fat content from powdered oils (sunflower, flaxseed, safflower, and algal oils). Previously, you had to dump a bottle of oil into your Soylent mix during prep—and the bottles were notoriously leaky during shipment, too. Now, everything's contained within one homogenized bag. This appears to have had a positive effect on shelf life, too, with the shipment we received showing "best when used by" dates of two full years.

Portions have changed, as well. I struggled to drink an entire mixed bag of Soylent for two days, laboring away under the impression that one bag contained a full day’s micro and macronutrients and therefore you had to eat a whole bag. Fortunately, Rhinehart set me straight and I backed off, stretching one bag out into about a day and a half’s worth of meals. For Soylent 1.4, the product has been re-labeled and its portion size adjusted down to reflect how people are actually eating it in real life; one bag now contains four servings instead of three.

Putting the "nutritive" in "nutritive slurry"

Since launch, Soylent has tested out to a carb/fat/protein ratio of 50/30/20 (that is, half of the stuff was carbs, 30 percent was fats, and 20 percent was protein). The 1.4 version shifts that somewhat dramatically, to 43/40/17.

"There was agreement that lowering the glycemic load and replacing the calories with fat, given our fat source is low in saturates and absent of cholesterol, would be healthier in the long run," explained Rhinehart in an e-mail exchange with Ars. "At the same time, more of our carbohydrates come from isomaltulose, which while appearing as a 'sugar’ on the label, has a lower glycemic index than the maltodextrin it replaces."

Also substantially changed is Soylent’s sodium level, up from 1080mg per bag to 1640mg. The idea behind the low initial sodium level was that most people get more than enough sodium from other foods and Soylent didn’t need to contribute to that; however, Soylent consumers who were eating nothing but Soylent for extended stretches began complaining of headaches and other odd symptoms that turned out to be related to sodium deficiencies. So, now there’s more.

Along with the sodium, 1.4 Soylent contains a substantial increase in chloride—up from 1260mg to 2300mg in a pouch. This one seemed a little odd, but Rhinehart clarified for us: "Sodium and chloride are oppositely charged ions used by the body for pH balance and signaling. It is important to get enough of both," he explained. "Previously, we were slightly low in both nutrients as we had difficulty providing the adequate intake without an unpleasantly salty taste. We were eventually able to find sources and balances of both individually, as in not using sodium chloride (table salt), to provide the full DV of each without compromising the experience."

Okay, now for the butt stuff

I’ve been drinking Soylent 1.4 on and off for the past seven days, including two full days of nothing but Soylent back to back, and I’m happy to report that the new formula does not in fact drive my gut flora to madness, nor does it cause my bowels to do this (that link is actually a really neat video that doesn’t actually have anything to do with poop).

I know "the farts are gone" is kind of an anticlimax, but there you go. It took more than a year to "debug," but Rhinehart is confident that they’ve got it right. "Both protein and soluble fiber were lowered slightly to alleviate the gas issues. This seems to have been successful. Reports of digestive distress have all but disappeared," he told us.

The decreased amounts of fiber and protein aren’t of major digestive consequence as long as you’re drinking enough water—something that the Soylent instructions repeatedly advise. Rhinehart is happy with where the levels are right now: "While most americans do not consume enough fiber, the amount present in 1.4 is well above the average intake," he elaborated, "and, given the elemental nature of the product, is ample to maintain a healthy digestive system while consuming Soylent along with other food."

Drowning in it

It’s going to take me some time to work through the month’s supply of Soylent I ordered (as with all previous Soylenting, we purchased our allotment through the company’s store), but at least for now I’m enjoying a quiet, clean-smelling home rather than trying to figure out how to save myself from myself with various multi-part blanket forts and ether-soaked bandanas. It’s nice to be able to know that a missed grocery store trip while on a deadline won’t mean instant ramen or a frozen dinner—I can just dip into my Soylent supply.

The release of the 1.4 formula appears to have broken the dam that had been holding back orders, as well; wait times for new Soylent customers have dropped from many months to about four weeks, with one unofficial order tracker showing huge swaths of orders being fulfilled at the end of March.

I’ve obviously long ago made peace with the fact that Soylent (in moderation) fits into my life; some people are all for the stuff, and others are painting it as downright toxic to human civilization itself. With new orders now shipping relatively quickly, there’s nothing stopping interested readers from trying some yourselves—though it definitely does take a bit of willpower to get through that first thick beige tasteless slurp. Mmmmm.