Acid Casein Market Overview in 2026 [Global Report]

The acid casein market entered 2026 under relatively stable conditions. The product was available both under contracts and on the spot market, and production in Oceania was sufficient to meet current demand.

The situation changed gradually as the season progressed. Declining milk availability in Oceania limited production, spot inventories began to shrink, and buyers had to accept increasingly higher price levels. The strongest price movement occurred during the summer, when the average price of acid casein exceeded 10,000 USD/MT.

The start of Q4, however, presents a different landscape than a few months earlier. The new dairy season in New Zealand is increasing raw material availability, while acid casein prices have stopped rising significantly.

Global Analysis of the Acid Casein Market

At the beginning of 2026, the market remained relatively balanced. In February, acid casein prices ranged from $3.85 to $4.25 per pound. Production in Oceania was stable, milk remained available, and producers were adhering to regular production schedules. Although most of the fresh production was allocated to contracts, inventories were sufficient to meet current spot demand.

However, the first factor supporting prices had already emerged. A stronger skim milk powder market was also putting upward pressure on acid casein. This stems from competition for the same supply of skim milk: plants can allocate the raw material to different products depending on margins, existing contracts, and production capacity.

In the following months, seasonality in Oceania began to play an increasingly important role. As milk production declined toward the end of the season, the capacity to produce acid casein also decreased. At the same time, demand did not weaken quickly enough to offset the reduced supply.

Prices clearly reflect this trend. The monthly average was approximately 8,741 USD/MT in January, 8,929 USD/MT in February and March, 9,108 USD/MT in April, and 9,381 USD/MT in May. In June, it rose to $9,645/MT.

The sharpest increase occurred during the summer. In July, the average reached approximately $10,295/MT, which was 6.7% higher than the previous month. In August, it rose further to approximately $10,541/MT. At the peak of summer trading, the upper end of the price range reached $5.50/lb, or approximately $12,125/MT.

However, the price pressure did not mean that Oceania simply ran out of milk for the season as a whole. In May, Fonterra reported that collections since the start of the season were 4% higher than a year earlier. The problem was a combination of the seasonal production profile, ongoing contracts, and the availability of acid casein for spot trading.

This is an important distinction. Data on total milk supply show production capacity but do not directly indicate how much acid casein will be available to buyers. Producers can adjust their product mix and direct the skim stream toward SMP, casein, or more specialized ingredients depending on price relationships and existing contracts.

Toward the end of the summer, the market began to show the first signs of stabilization. The September average fell slightly to $10,472/MT. From late August through October 2, the price range remained largely between $4.25 and $5.25/lb. This indicates that, following a sharp rise in July, upward pressure on prices had clearly eased.

In early October, however, the range of $9,370–11,574 per metric ton remained well above last year’s baseline. Converted to euros, the average was about 22.6% higher than a year earlier. The market is therefore entering Q4 following a strong rally, rather than from a neutral price level.

Regional Analysis of the Acid Casein Market

The acid casein market is much more geographically concentrated than many basic dairy commodities. Oceania, particularly New Zealand, remains the most important supply source. The United States, on the other hand, is the key import market and a benchmark for international prices. Europe and Asia primarily influence global demand trends and trade flows.

Oceania

New Zealand remains the central market for the global supply of acid casein, which is why the course of the local dairy season directly affects the situation for buyers on other continents.

The first months of 2026 were relatively calm. In early February, milk was readily available, acid casein production was stable, and inventories were sufficient to fulfill both contracts and spot sales.

The situation began to change with the natural decline in milk supply during the second half of the season. Acid casein production was curtailed, while the majority of the available product went to contract customers. As a result, buyers seeking additional volumes on the spot market faced increasingly limited availability.

At the same time, the entire milk season was strong. In May, Fonterra reported collections up 4% year-over-year and expected high supply to continue into the next season as well.

It is precisely this discrepancy between the strong overall seasonal balance and the limited availability of acid casein in its final phase that best explains the 2026 market. It is not enough to know how much milk was produced in New Zealand. For the buyer, what matters most is when during the season the raw material is available, which product is profitable for the producer to manufacture, and how much volume has already been contracted.

The start of the 2026/27 season changes this picture. Fonterra expects collections to be slightly above 1.6 billion kgMS for the entire season and anticipates another period of strong milk supply. As of the end of August, collections since the start of the season totaled 142.9 million kgMS.

This provides producers with a better raw material base for increasing production in Q4. However, it does not determine what portion of the additional milk will be allocated specifically to acid casein.
At the same time, Fonterra emphasizes the importance of optimizing the product mix and shifting milk toward higher-value protein ingredients. In FY26, the Ingredients business benefited from both strong global demand for proteins and a favorable product mix.

North America

The United States should primarily be viewed as an import market for acid casein.

The USDA’s weekly benchmark covers the U.S. market for imported casein and provides spot prices and contracts up to three months out, as well as information on supply, demand, and inventories.

As a result, supply tensions in Oceania quickly become apparent in the U.S. benchmark. From January through August, the average price of acid casein rose from approximately 8,741 to 10,541 USD/MT. In September, there was a slight correction to about $10,472 per metric ton, but prices remained significantly higher than at the beginning of the year.

Changes in trade with New Zealand are also significant. In August, the value of New Zealand’s exports of the broad category “casein and caseinates” to the U.S. was NZD 43 million lower than a year earlier. However, these figures cover a broader range of products than acid casein alone, so they cannot be interpreted as an exact decline in acid casein supplies.

For the U.S. market, export availability from Oceania will therefore be the most important factor in Q4. If a stronger dairy season translates into a greater volume of acid casein available beyond existing contracts, U.S. buyers should gain more room to negotiate. However, if the additional product is quickly contracted by buyers in other markets, prices may remain high.

Europe

Europe plays a different role for acid casein than it does for rennet casein. It is not the primary benchmark for the production of the product discussed here, but it remains a significant destination market for dairy ingredients from Oceania.

New Zealand trade data suggest that the direction of trade flows shifted during 2026. In August, the value of exports of the aggregated “casein and caseinates” category to the European Union increased by NZD 17 million year-over-year, while shipments to the U.S. declined.

However, these figures should not be equated solely with acid casein. The statistics also include other types of casein and caseinates.

For European buyers, high acid casein prices increase the importance of formulations and price relationships with other milk proteins. However, the possibility of substitution depends on the technological application; therefore, a change in the price relationship does not automatically lead to a shift in demand toward SMP, MPC, or other proteins.

Asia

Asia remains an important part of the global market for New Zealand dairy products; however, publicly available data that would allow for a reliable distinction between acid casein, rennet casein, and caseinates in 2026 is limited.

For this reason, the region should not be assessed based on broad data covering all milk proteins. In the case of acid casein, the direction of total import demand from Oceania and competition among individual markets for limited volumes are of greater significance.

If Asian demand remains strong during the seasonal peak in New Zealand production, some of the additional supply could be quickly absorbed. Weaker purchases, on the other hand, would increase the likelihood of a larger volume of the product appearing on the U.S. and European markets.

Trends and Outlook for Q4 2026 and Early 2027

Acid casein enters Q4 from a much stronger price position than at the beginning of the year, but without the same upward momentum seen during the summer.

The first sign of a shift is price stabilization. After the monthly average rose to $10,541/MT in August, September saw a slight decline to $10,472/MT. The price range of $4.25–5.25/lb remained unchanged for most of September and early October.

The second sign is an improvement in the raw material supply. The new season in New Zealand means rising milk collections, and Fonterra expects 2026/27 to be another period of strong milk supply, with collections slightly above 1.6 billion kgMS.

This increases the likelihood that acid casein availability will begin to improve in Q4. However, the key distinction is between higher production and higher spot supply.

If producers use the additional milk to increase acid casein production, and if prior contracts no longer absorb the majority of current production, the market may gradually ease. In such a scenario, pressure for further price increases should be limited, and buyers may regain greater bargaining power.

The new dairy season in New Zealand is improving the raw material supply, but for the acid casein market, the key factor will be how much of the additional production actually reaches the spot market. In the first half of the year, a strong milk balance was not enough to prevent market tightness, as the product was largely tied up in contracts and production was declining toward the end of the season. If higher milk collections in Q4 lead to a replenishment of available volumes, the market should gradually stabilize. If the additional production is quickly contracted, high prices may persist for much longer.

Mateusz Augustyniak

Board Member and Partner at Foodcom S.A.

The base-case scenario for Q4 is therefore stabilization with the possibility of moderate downward pressure, rather than another wave of price increases on the scale seen in July.

Arguments in favor of a more subdued market include the seasonal increase in milk production in New Zealand and the price stabilization already evident since August. However, the strong demand for protein, the high share of contract sales, and the possibility of diverting milk to other products offering producers attractive margins remain arguments against a sharp correction.

Weather also remains a risk to this scenario. Fonterra, in planning for a strong 2026/27 season, highlights the possibility of El Niño-related conditions. A potential decline in milk production could quickly reduce the expected improvement in raw material availability.

In early 2027, the market’s direction will depend primarily on whether the increased New Zealand milk supply builds up real acid casein inventories or is absorbed by contracts and strong demand for high-protein ingredients.