From Salt to Zinc: Red Wing Pottery’s Transition between Stoneware Glazes

An easy example of stoneware jugs turned out during between 1895 and 1900, when the Red Wing and Minnesota Stoneware companies transitioned from a salt glaze (left) to a zinc glaze (right).

When it comes to the period between 1895 and 1900, when the Red Wing and Minnesota Stoneware companies moved away from making salt glaze stoneware, some very unique pieces were turned out of these potteries.

This time frame is known by collectors as the Transition Era, as it is when potteries around the country began to produce white-glazed ware because it was easier to make and was higher in quality. According to “Red Wing Potters & Their Wares,” by Gary and Bonnie Tefft, the white, opaque glazes were developed in Bristol, England, which is why they’re referred to as Bristol glazes. (Collectors often refer to Red Wing stoneware carrying the red wing, birchleaf and Elephant Ear decorations as “zinc glaze” or “white glaze,” so these two terms are used interchangeably in this article.)

Why the Change?
One of the biggest advantages that zinc glaze held over salt glaze was in the quality. Zinc glaze was stronger, more consistent and less likely to show stains from lard and other contents. Anyone who has collected for awhile will tell you that they’ve seen many more pieces of salt-glaze stoneware with stains than they have zinc glaze. In addition, glaze pitting, caused by exposure to acid, is much more common on salt glaze than it is on zinc glaze.

Another significant advantage of white-glaze stoneware is that it could be manufactured and decorated faster and with less skill than salt glaze. Thus, Red Wing could make a better product and they could make it faster and cheaper than before.


As the potteries began to invest in rubber ink-stamped numbers, it’s clear they started with smaller sizes first because small pieces were ordered more often by consumers. Elephant Ear crocks sized 2- through 6-gallons always seemed to have the number applied with a rubber ink stamp. However, earlier Elephant Ear crocks ranging in size from 8- to 40-gallons have the gallon capacity hand-drawn in cobalt.

This 2-gallon zinc-glaze beehive jug not only has excellent form, but also some great turkey droppings, indicating that it’s probably a transition piece because salt glazing still coated the ceiling of the kiln and dripped onto the jug. This particular piece sold for more than $200 on eBay in January, but it’s likely it wouldn’t have topped $50 without turkey droppings.

“Applying Albany slip to the inside of the crock was no longer necessary,” says longtime Red Wing Stoneware collector and dealer Larry Peterson. “Plus, they needed a talented artist to decorate stoneware with leaves and butterflies and that took time, but anybody could quickly stamp a set of elephant ear leaves on the side of a crock.”

The stark white backgrounds of zinc-glazed pieces also lent themselves better to advertising stamps for companies looking to put their names on crocks, jugs and churns. In addition, the white glaze also made it easier for people to tell how well they cleaned a piece of stoneware after using it.


These two 8-gallon crocks were obviously decorated by the same person, so it’s possible that they were made only months or even days apart. The transition piece is stamped “Red Wing Stoneware Company” on the front.

These ice water coolers really help tell the story of what was going on at the time in Union Stoneware’s history. They’re virtually identical except for the fact that the one on the far left is salt-glazed and the one on the far right has a white-glazed interior. From left to right: unsigned salt glaze, front-stamped Red Wing Stoneware, Union Stoneware oval and Minnesota Stoneware oval.

Transition History
White-glazed stoneware was first available for purchase in 1895, according to Union Stoneware Company price lists, but as the Teffts report in their book, only pieces 1-gallon and smaller were manufactured at first. This is because the soot and ash produced by the wood and coal fuels would ruin white-glazed wares, so they had to be placed in larger salt-glazed crocks when they were in the kiln to be protected from the impurities. The Teffts say that protective fire-clay containers called saggers were also used to “keep the ware out of the direct draft of the kiln fire.” By 1895, however, the kilns were converted to oil heat, so soot and ash were no longer problems.

Less than a year later, the Oct. 1, 1896 Union Stoneware price lists offered more white-glazed pieces, but still nothing larger than a 20-pound bailed jar with lid. The price list reproduced in the Tefft book shows that white-glazed pieces were priced slightly higher than the same pieces that were all brown or salt-glazed.


These success filter tops both have a rubber ink stamp, but the toggle wheel decorations indicate that the salt glaze version is a Minnesota Stoneware piece and the transition version is a Red Wing Stoneware piece.

This 4-gallon Elephant Ear crock (left) has an Albany slip interior, a Union Stoneware oval and a Red Wing Stoneware Company side-stamp. Larry Peterson sold a 20-gallon Elephant Ear crock with Union oval last summer that was back-stamped. This remarkable 3-gallon transition crock (right) has both a hand-drawn cobalt number with target decoration AND an ink-stamped number, Elephant Ear decoration and Union oval. Who knows? If the worker who decorated this was feeling sentimental, maybe it’s the first piece to have an ink-stamp and last to have a cobalt decoration.

When Larry Peterson acquired the 30-gallon F.A. Morley jug, he dug deep with his research to figure out when it was made and he was amazed to discover that the early pieces of zinc-glaze stoneware were older than he thought. He believes the third branch of the Union Stoneware Co—the North Star Stoneware Company—might have caused that misconception among collectors.

“I think one reason people believe that zinc glaze wasn’t made until 1897 and beyond is that the North Star Stoneware Company was only known to produce salt glaze, and they ceased operation in 1896,” Peterson says. “But the fact is, they were struggling to stay afloat, so experimenting with white glaze probably wasn’t an option for them like it was for the larger of the three companies.”

By the time 1897 rolled around, the Red Wing and Minnesota Stoneware companies were turning out huge amounts of quality zinc-glazed wares. The Teffts cite a June 16, 1897 article from the “Red Wing Daily Republican” in which the reporter describes seeing a load of white-glazed stoneware being taken out of a Minnesota Stoneware kiln:

“Two years ago had you told the managers of these works that white ware would be made here, they would have looked at you with the eye of a skeptic. Yet here was presented a kiln of ware of the purest creamy white glaze, uniform in color throughout, firm in body, perfect in form; in short fulfilling every particular all that could be desired by anyone in stoneware manufacture.”


The Union Stoneware Company booth at the Trans Mississippi & International Exposition in Omaha, which started on June 1, 1898.

The best and perhaps the only photo to reference from the Transition Era is that of the Union Stoneware Company booth at the Trans Mississippi & International Exposition in Omaha, which started on June 1, 1898. It shows crocks, jugs and churns decorated with a mixture of rubber stamp-applied Elephant Ear leaves and capacity numbers, and hand-drawn cobalt leaves and capacity numbers.

There are also some ornately decorated pieces of transition stoneware in this photo that put to shame most of the transition pieces we’ve seen to date. Clearly, these pieces were made specifically to display at the exposition, as they carried the Union Stoneware name in big, bold script. Red Wing wanted to put its best foot forward in showing the country what it could do, and as the photo indicates, it was successful in doing so. But what happened to these pieces? One theory among collectors is that they were destroyed at the end of the Omaha exposition so they wouldn’t have to be shipped back to Red Wing. It’s more fun, however, to dream that they were sold to the locals and today a few are out there somewhere sitting in an old Nebraska barn or basement. Even though more than 100 years have passed since the exposition and none of these impressive pieces have shown, it’s always possible that one of them might surface someday. We can only hope. . .

The Teffts write on page 67 of their book that the transition to white-glazed wares was complete in 1900. They cite the following quote from the 1902 “Red Wing Year Book”:

“Their most radical change in wares was about three years ago when they discarded the dark glaze in favor of the white glaze which is the highest stoneware product to be made. After that comes the art of making wares from mixed bodies in every degree of intimacy.”

The Oddities That Make Collecting Fun
One thing that’s clear about Red Wing’s transition is that it didn’t take place at the flip of a switch, because a combination of old and new production techniques are found on a variety of pieces made during this time. The intermingling of Albany slip interiors, hand-drawn numbers and decorations, rubber ink stamps and “Red Wing Stoneware Company” and “RWSCO” stamps impressed into the clay are a sign that a lot of experimentation was taking place. What’s really intriguing is that it wasn’t like there was a quality-control department in place to keep these pieces from getting out. They were being sold just like everything else, and that’s why so many different variations of the same piece exist today.

Most collectors believe that the rubber-stamped Elephant Ear leaves predate the rubber-stamped birchleaves, and the number of Elephant Ear transition pieces existing out there certainly support this theory. In collecting photos for this article, plenty of transition Elephant Ear pieces were found and used, but the only photo of a transition crock with birchleaves is the 40-gallon. There’s also a 25-gallon birchleaf crock just like it on page 49 of “Red Wing Stoneware.” Because the potteries didn’t make many 25- and 40-gallon crocks early on, it’s likely that the rubber-ink stamps for these sizes hadn’t been made at that point.

The decorated pieces shown in the 1898 expo photo only have hand-drawn cobalt leaves and rubber-stamped Elephant Ear leaves. This serves as additional proof that Elephant Ear leaves came first, as no birchleaves are visible on pieces in the Union Stoneware booth.

Gary Tefft suggests the Elephant Ears were abandoned soon after, possibly because it was more difficult to apply without making a misprint. This makes sense, as you often see Elephant Ear pieces that appear to be double-stamped with one set of leaves right on top of the other. This is less-often the case with the birchleaf decoration.


These 2-and 5-gallon crocks are salt-glazed, but also have rubber-ink stamped Elephant Ear leaves.

Because there are salt-glaze and zinc-glaze crocks out there that bear identical hand-drawn cobalt decorations, one would think that the production of new white-glazed pieces signaled that the last salt-glaze piece had been produced. However, the photos of the 2- and 5-gallon salt-glaze Elephant Ear crocks with Albany slip interiors and the Union oval (photos 8a and 8b) prove otherwise. Although it doesn’t seem possible, these were probably made sometime after the first zinc glaze stoneware bearing hand-drawn cobalt decorations, even though they’re salt glaze pieces. To add to the perplexity, Tefft recalls seeing a few salt glaze pieces that had the rubber-stamped birchleaf decoration at an RWCS convention that took place sometime before 1981. He says he’s seen a few since then, as well. These are obviously quite rare, as no photos exist in books or old RWCS newsletters.

On the other end of the spectrum, the absence of certain hand-drawn cobalt decorations on transition stoneware tells us which decorations were earlier than others. Since only targets, leaves and butterflies have been seen on white-glazed pieces, it’s likely that decorations like ribcages, drop-8s, single Ps and specialty decorations like birds, lilies and flowers were no longer used by the mid-1890s. But just watch . . . now that this article has been published, a zinc-glaze transition crock with a bird will probably show up. It always seems to happen that way.


This Mennig & Slater advertising churn is quite desirable, not only because it’s only 1-gallon in size, but also because its Albany slip interior makes it a transition piece. A 5-gallon salt glaze churn with a hand-drawn “5” and rubber ink-stamped Mennig & Slater oval is pictured on page 52 of “Red Wing Collectibles.”

An impressive grouping of transition churns with hand-drawn cobalt leaves, some of which are front or back stamped “Red Wing Stoneware Company” or “RWSCO.”

Until recently, only zinc-glaze transition crocks and churns have been found with hand-drawn cobalt decorations. When asked if they’d ever seen or knew of a white-glazed beehive jug or water cooler with a hand-drawn cobalt decoration, both Larry Peterson and mega-collector Lyle Berman said they hadn’t. It’s possible that the 5-gallon zinc-glaze transition beehive jug with hand-drawn cobalt leaf pictured above (10a & 10 b) is the only one known to exist at this point, but if there’s one out there, conventional wisdom tells us there could be more.

Still, no transition water coolers with hand-drawn cobalt decorations are pictured in books or known to exist by the general population of Red Wing collectors. The transition coolers that do exist have a rubber-stamped “Ice Water” ink label and, just like other transition pieces, bear either a rubber-stamped Union Stoneware ink oval, a Minnesota Stoneware ink oval, or the “Red Wing Stoneware Company” signature from the salt-glaze era stamped into the clay (see photos 4a-4d, above). We aren’t aware of any zinc-glazed transition pieces being side-stamped with the Minnesota Stoneware Company split oval, but again, that’s not to say that one won’t turn up someday.


Transition crocks with hand-drawn cobalt leaves were usually made between 5 and 30 gallons in size, but this 40-gallon is the only known to exist and predates the 40- and 25-gallon Elephant Ear crocks with hand-drawn numbers. Forty- and 25-gallon Elephant Ear crocks seem to only have hand-drawn cobalt numbers, as do a few early 40- and 25-gallon birchleaf crocks (see photo 11d). These ink stamps probably hadn’t been made yet because the crocks were odd sizes that weren’t ordered as often by consumers.


Believe it or not, this 4-gallon salt glaze leaf churn has a white glaze interior! Unfortunately, a photo of the inside couldn’t be located, but it sold on eBay in March of 2007.

Although we’ll probably never know everything there is to know about Red Wing’s Transition Era, the fun thing is that new pieces are always being found or “re-discovered” so they can be documented with a photo and shared with all collectors. The potteries made so many pieces with unique attributes during this time that anybody has the opportunity to find something that wasn’t previously known to exist, even though collectors have been paying closer attention in the 30-plus years that the Red Wing Collectors Society has been around.

Rick Natynski is the editor of the Red Wing Collectors Society Newsletter. The Red Wing Collectors Society was founded in 1977 in Red Wing, Minn. and is devoted to educating people about all American pottery. There are more than 4,000 members worldwide. The Red Wing Potteries had diverse pottery lines that included stoneware, dinnerware and art pottery. For more information or to become a member, call the RWCS business office at 800.977.7927, e-mail or log on to


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