There is no material evidence that anyone in Portland has ever stirred quick-drying cement into a vegan milkshake.

Until this week—when we did.

Portland city officials have spent the past week distancing themselves from a June 29 warning issued by the Portland Police Bureau on Twitter that leftist protesters might have mixed quick-drying cement with vegan milkshakes. That rumor, combined with a documented assault by masked antifascists on a conservative journalist, inspired what the mayor now calls a "global frenzy" of right-wing contempt for Portland.

The week's events added to frustrations about Portland police's inability to curb violent street brawls.

But as WW first reported last week ("On Shaky Ground," July 3, 2019), no one has shared photos, videos or other physical evidence of the rumored concrete concoctions.

Police now admit the bureau has no physical evidence to support the claim—and Chief Danielle Outlaw said in a press conference July 3 that she hopes it turns out the milkshakes were just milkshakes.

We had a lot of questions about the cement milkshake allegation.

Can quick-dry cement be mixed with sugary, frozen non-dairy ice cream? Would the mixture splatter like a milkshake? What would a cement milkshake even look like?

WW decided to find out. We bought a 50-pound bag of Quikrete from a hardware store in Northeast Portland and two vegan vanilla milkshakes from Burgerville. Then, we got to mixing.

Control test: We tossed an untainted milkshake at a mannequin wearing a bandanna that could be used as a mask to conceal her identity if she committed crimes.

(Sam Gehrke)
(Sam Gehrke)

Result: The shake splattered beautifully across her expressionless face, and dripped off in ribbons of melted coconut cream. This is also how people who were splashed in the streets of Portland on June 29 looked in news photographs.

(Sam Gehrke)
(Sam Gehrke)

Test A: We mixed six spoonfuls of Quikrete into a half-full milkshake cup. The mixture thickened slightly and turned dark gray.

(Sam Gehrke)
(Sam Gehrke)

Result: It splattered across the mannequin just fine, but left behind an unmistakable, gritty sludge that could never be mistaken for the vegan milkshake we started with.

(Sam Gehrke)
(Sam Gehrke)

Test B: We mixed more concrete with the remaining milkshake. We let it sit for 10 minutes—and then tossed it.

(Sam Gehrke)
(Sam Gehrke)

Result: A little more than half of the mixture splattered our fake victim, but a fair amount of the mixture stuck to the inside of the cup as wet, clumpy muck. The splatter looked nothing like a milkshake. It looked like wet concrete.

(Sam Gehrke)
(Sam Gehrke)

Two hours later, the cement-milkshake mixture coating our dummy was still squishy and wet. It had not dried, as quick-drying concrete is supposed to do.

Conclusion: It's definitely possible to mix quick-drying cement with a vegan milkshake—but the result would be immediately obvious and would leave behind a telltale mess that's tough to clean up.

The runny white splatter of the milkshakes protesters threw on June 29 did not look at all like our quick-drying concrete cocktail.

Neither the Portland Police Bureau nor any witness has been able to produce credible evidence that a single cement milkshake was thrown June 29. But a concrete milkshake is distinctive, as we learned. It's gritty, clumpy and a dark color. If such concoctions weren't seen June 29, that is almost certainly because there weren't any.