Gray Potatoes Grossing You Out? Our Tests Show How to Stop It

Anyone who has made latkes, rösti, or hash browns has watched the clock start ticking the moment a potato is shredded. The potatoes that look pale and fresh at first turn rosy, then gray, in the span of a few minutes.

The usual advice is familiar and often conflicting: Rinse the potatoes. Soak them. Add salt. Add acid. Work fast. Or don't worry about it at all. Some cooks insist discoloration affects flavor and texture; others argue it disappears as soon as the potatoes hit a hot pan.

To separate useful techniques from kitchen lore, I tested several common approaches side by side, measuring how they affected discoloration over time, and then cooked them up to see how they looked and tasted on the plate.

Why Shredded Potatoes Turn Pink and Gray

When a potato is shredded, its cells rupture. This brings polyphenol oxidase (PPO), an enzyme naturally present in potatoes, into contact with oxygen and phenolic compounds that were kept apart inside intact cells. PPO oxidizes those phenolics into quinones, which then form colored pigments. This is enzymatic discoloration.

While we often think of oxidized foods like apples turning brown, that is not the only color that can result from these reactions. In potatoes, enzymatic discoloration can appear pink, rosy, or gray depending on the potato's phenolic profile and the chemical environment at the cut surface, including pH and salt concentration. Because the reaction is enzymatic and time-dependent, discoloration intensifies the longer the shredded potatoes sit.

The Testing Framework

To see how different treatments affect discoloration, I compared five common approaches applied to freshly shredded potatoes:

• No treatment (control)
• Plain water rinse (no soak)
• Plain water soak (soaked for 5 minutes)
• Acidulated water soak (soaked for 5 minutes)
• Salted water soak (5 minutes; 1 teaspoon kosher salt per 1 cup water)

Each batch was observed at 5, 10, 15, and 30 minutes after shredding to track how the color changed over time. For the soaked treatments, the potatoes were drained, wrapped in a clean towel, and gently squeezed to remove excess water before observation and cooking. All other variables, including potato quantity, handling, and exposure to air, were kept consistent so that any differences could be attributed to the treatments themselves.

Results: How Different Treatments Affected Graying

Control (No Treatment). Untreated shredded potatoes discolored the fastest and most dramatically, developing a rosy tint by 5 minutes that grew deeper by the 10-minute mark, and turning distinctly grayish-pink by 30. With no dilution, no pH change, and unrestricted exposure to oxygen, polyphenol oxidase (PPO) remains fully active at the cut surfaces. As oxidation products accumulate over time, pigment concentration increases, deepening the color.

Plain Water Rinse (No Soak). A brief rinse slowed discoloration but did not prevent it. Rosiness still appeared by 5 minutes and intensified gradually through 30 minutes, though it remained noticeably lighter than the control throughout. Rinsing washes away and dilutes some surface enzymes and phenolic compounds, reducing the initial rate of oxidation. However, because PPO remains active and the drained shreds are quickly re-exposed to oxygen, browning continues along the same pathway.

Plain Water Soak (5 Minutes). A 5-minute soak delayed discoloration more effectively than a rinse alone. Even after being squeezed dry, there was no visible change at 5 minutes, with very slight rosiness appearing by 10 minutes and increasing subtly at 15 and 30 minutes. The longer soaking time increases dilution and leaching at the cut surfaces, further slowing PPO-driven reactions without chemically inhibiting the enzyme.

Salted Water Soak (5 Minutes)—Second Best. Salted water (1 teaspoon Diamond Crystal kosher salt per 1 cup water) also limited discoloration: No visible change at 5 minutes after squeezing dry, minimal change through 10 to 15 minutes, and only mild darkening by 30. Notably, the discoloration read grayer and less rosy than the plain-water treatments. Because salt does not lower pH, it does not inhibit PPO the way acid does. Instead, it alters the ionic environment at the cut surface, potentially altering PPO activity and shifting the balance of oxidation products. Under these specific conditions, the salted soak reduced visible discoloration compared with the plain-water treatments and produced a duller, grayer cast rather than a pink one.

Acidulated Water Soak (5 Minutes)—Clear Winner. Acidulated water prevented visible discoloration through 15 minutes and showed only the faintest warmth or hint of rosiness by 30 minutes. PPO activity is sensitive to pH. Potato PPO tends to be most active in the mildly acidic to near-neutral range; shifting conditions toward greater acidity inhibits its ability to catalyze oxidation. Unlike water alone, acid actively suppresses the reaction rather than merely slowing it.

Will the Soak Make Potatoes Too Wet?

In these tests, a short soak did not hurt crisping. Patties made from briefly soaked potatoes crisped just as well as those made from unsoaked potatoes once they were drained, squeezed, and seared in hot oil. I did not detect meaningful differences in exterior browning or texture between the soaked and unsoaked samples.

A short soak can add surface water, but it does not necessarily water-log shredded potatoes in practice. During brief soaking, most water remains on the surface of the shreds rather than penetrating deeply into the intact cells; draining and squeezing the shreds removes much of it. With longer soaks of more than 30 minutes, however, potatoes can absorb water, which can soften the tissue and reduce browning and crisping during cooking.

Does Graying Matter Once the Potatoes Are Cooked?

Of course, discoloration in the bowl is one thing; what happens in the pan is what most cooks care about. To compare the treatments fairly, I cooked them side by side. All samples were prepared and cooked the same way. The shredded potatoes were bound with the same amount of flour and egg, shaped into small patties, and seared in a skillet with neutral oil until well browned on both sides.

The untreated control was the clear outlier. It cooked up noticeably grayer than all the other samples and was the only batch that looked genuinely unappealing. The rinsed potatoes were also on the grayer end of the spectrum, but far less jarring than the control.

Among the remaining treatments, differences were subtle. The acidulated soak produced the whitest interior, followed closely by the salted soak and the plain water soak, which were very similar in appearance. The water rinse landed just behind them. In practical terms, most people would not notice the differences among the treated samples unless they were viewed side by side.

While discoloration can look visually off-putting, even the most oxidized samples did not taste off after searing. That aligns with the underlying chemistry. Enzymatic discoloration produces pigments that are visually obvious but don't necessarily impact flavor and aroma to the same degree. Once cooking begins, heat denatures polyphenol oxidase and stops the reaction. At the same time, flavors produced by heat-driven browning reactions, such as Maillard reactions, dominate our perception. Changes in surface texture and browning during cooking also help reduce the visibility of mild pre-cooking graying.

That said, the salted soak had a clear flavor advantage. The potatoes tasted lightly seasoned throughout, which was noticeable and pleasant. The acidulated soak is also a good choice, since it prevents discoloration the most yet does not impart any detectable sourness once cooked. In theory, you could combine salt and acid in a single soaking solution to get the color and flavor benefits of each.

The Takeaway

In the end, shredded potatoes are more forgiving than they look. Graying happens fast, but aside from the off-putting appearance, flavor and aroma are not significantly harmed. If that sickly color of oxidized potatoes is enough to kill your appetite, though, a brief soak is enough to keep the graying under control for the first 15 to 30 minutes, and once the potatoes hit a hot pan, most of the drama disappears. If you want the whitest flesh, a little acid helps, while salting the soaking water improves flavor throughout. If you opt not to apply any color-preserving treatments but still don't want latkes that look like mudcakes, the least you can do is work fast.