Unprecedented demand for egg whites has pushed prices to record highs as major fast-food chains increase offerings of healthier alternatives for breakfast. But the rise in egg white demand has left a “casualty” in its wake — egg yolks — which are languishing in oversupply.

Nearly all fast-food and quick-service restaurant chains now feature one or more whites-only breakfast items, but the surge in egg white demand and prices mostly mirrors the introduction of McDonalds’ Egg White Delight (a revamped Egg McMuffin) in April 2013.

“The egg white craze started ridiculous and took off from there,” one egg processor said, noting that he has recently had to ration sales of dried egg whites and dried whole eggs to his customers.

“It’s hurt small bakeries the most,” another egg processor noted, adding that they “can’t keep dried whites in stock.”

Most restaurant chains featuring egg white entrees buy them as patties from food processors or from a limited number of large egg processors who both break eggs and process them into restaurant-ready products. Most egg processors produce liquid, frozen and dried whole eggs, whites, yolks and blends, but do not process the products into restaurant-ready items. The huge demand for liquid whites has limited the supply of whites, as well as liquid whole eggs, to driers, thus reducing the supply of dried eggs and pushing prices to record highs.

Current prices for dried egg whites are the highest in Milling & Baking News records going back to December 1979. Prices for dried egg whites were quoted last week at $8.15@8.70 a lb f.o.b. the plant by Food Business News and Milling & Baking News, up 50% since mid-April, up 75% since February and up 60% from a year ago. The previous high-water mark for dried whites was $6.95@7.45 a lb in April 2004. Delivered prices topped $9.25 a lb recently in some areas.

Prices for frozen egg whites were quoted last week at $1.05@1.08 a lb, up over 50% from 2013 lows in early February. Prices for liquid whites at 93@95c a lb have surged more than 90% from lows in early January. Prices for both were the highest in Food Business News records going back to March 2005 and eclipsed previous highs of 98@104c a lb for frozen whites and 85@90c a lb for liquid whites, both set in March 2008.

The rise in demand for egg white entrees has turned traditional egg product price relationships upside down. Dried egg whites historically have traded (roughly) at a 50% to 75% premium to dried egg yolks because liquid whites contain more water than yolks and thus cost more to dry. The price difference has varied widely over the years from whites being more than double the price of yolks to yolks being at a premium to whites. Currently dried egg white prices are about four times the price of dried yolks.

The opposite typically is true for frozen and liquid products. Because frozen and liquid whites contain more water than yolks, the yolks typically are at a premium to whites. Price differences have varied widely from a 25% to 50% premium (roughly) for yolks, typically, although liquid yolks have been priced two to four times the price of liquid whites on occasion. Currently frozen and liquid whites are trading at a premium to yolks.

Obviously for every egg broken for its whites there is a corresponding yolk. The surge in demand for whites has resulted in an excess of yolks, while some domestic demand for yolks has eased as breakfast sandwiches that before contained whole eggs now are whites only.

Prices for yolks have declined during the same time period that white prices have surged. Dried yolk prices currently quoted by Food Business News at $2@2.20 a lb are down about 20% from February and down more than 35% from a year ago. Frozen yolk prices quoted at 96@100c a lb are down about 15% from February and 35% from October 2012. Liquid yolk prices at 72@74c a lb last week are down about 20% from February and 45% from last year.

One processor noted demand from Mexico for egg yolks supported prices for a while earlier this year, but that demand recently has eased and prices are falling.

Egg processors have found supplies of frozen and liquid eggs for drying in tight supply and frequently have been sold out of egg white and whole egg products.

The question is whether the high level of demand for egg whites will continue or whether it’s a “flash in the pan.” Processors contacted by Food Business News indicated no let-up in demand since earlier in the year, and in fact they have seen demand increase as other restaurant chains have followed McDonald’s lead, and as company’s such as Hillshire Brands have begun offering frozen breakfast sandwiches under its Jimmy Dean brand that feature egg whites.

Processors also have concerns about supplies this fall, with the strongest demand for eggs typically running from early October to early December.

“If retail (egg demand) picks up closer to Thanksgiving and gobbles up shell eggs,” supplies available for drying may become critical, one processor said. While retail and breaking egg markets typically are separate, when prices for graded shell eggs for retail get high enough it pulls eggs away from the breaking market.