Buttermilk and whey used to be a common part of our kitchen. After several years of "absence," they are reappearing on the market and becoming part of our diet. The company Milk-Agro introduced their dried version in a 400-gram package. We discussed this with Ing. Peter Kočiš, head of dairy production in Sabinov.
You are launching dried buttermilk and whey. Why did these healthy drinks disappear from the market?
Our parents consumed them regularly, and buttermilk was commonly sold in stores. We also produced and sold it as a supplementary product in our production. But when production was reduced at the turn of the 1980s and 1990s due to the loss of original markets, we stopped producing butter and thus also stopped selling buttermilk because it was no longer profitable for us. Previously, we belonged to the East Slovak dairies; individual operations specialized, for example, Sabinov made yogurts, butter, curd, and filled bagged milk, and surplus milk was dried here. Prešov produced curd desserts and bagged milk; each dairy produced something different and sold it within the region. Nothing was transported far; what was produced here was consumed here and was fresh. Now a lot is transported; for example, it is produced in Germany and sold in Slovakia. It is not ecological, but economic pressure forces rationalization…
...so buttermilk stopped being sold...
Only in 2005 did we return to butter production, and thus to the production of buttermilk as its by-product. We thought about what to do with it. We could have sold it as technological leftovers for animals, but that would be a devaluation because buttermilk is a very valuable raw material, relatively even more valuable than skimmed milk. And since we had drying capacities because we dry milk, we decided to dry this valuable raw material. This dried buttermilk in bulk packaging (25 kg) was and is taken by bakeries and confectioneries from us as a full substitute for dried milk.
But the buttermilk that was sold tasted a bit more sour than milk...
Buttermilk can be sour or sweet, depending on the technology used to make butter. If butter is made from fresh cream by the so-called "sweet" technology, sweet buttermilk is produced, which has comparable values and taste to milk. Compared to buttermilk made at home, which had a sour taste because the milk was left to stand at room temperature to let the cream rise and uncontrolled fermentation of the cream occurred. Therefore, butter and buttermilk made from such soured cream had a sour taste.
Could you explain the "sweet" butter-making technology?
In this method, the cream does not ferment but matures by so-called physical ripening. This means fresh cream is pasteurized and then cooled to 4–8 °C. At this temperature, it matures for at least 8 hours. Then the churning process follows. The cream goes into the churn, where at certain speeds and mild heating to 12–13 °C, it clumps into butter grains, separating buttermilk from butter. This buttermilk is collected, repasteurized, and then dried.
Drying is also a fairly sophisticated process...
Yes, as far as I know, in Slovakia we are among the few who process by-products (buttermilk, sweet whey, sour whey) this way. We use gentle spray drying, which preserves most of the nutritional values of these dairy products. The drying process itself is divided into two parts: first, the liquid dairy product (milk, buttermilk, and whey) must be concentrated to 40–45 refractometric degrees, and only then does the actual drying of the concentrated dairy intermediate product take place in the drying tower. There, the concentrated liquid is dispersed into a mist and then water evaporates from this mist by a stream of hot air at 170–190 °C. The result is a powdery consistency of dried milk, buttermilk, and whey.
The temperature of 190°C is quite high...
Yes, but that is the temperature of the injected air. Since the mist of concentrated intermediates still contains a relatively high water content (55–60%), evaporation consumes heat (we also cool ourselves by sweating), so the temperature inside the "grains" is only about 70 °C. The resulting dried product and the proteins contained in it are thus not denatured.
You dry milk, buttermilk, and whey this way. What is the difference between them?
Dried milk contains everything that liquid milk contains, except water, which remains only about 4%. Dried buttermilk is very similar to dried milk but contains more fat than skimmed dried milk, which has a maximum of 1.5% fat. Dried buttermilk contains 6–9% fat in dry matter, full-fat dried milk up to 26% fat in dry matter. Buttermilk also contains much more phospholipids than skimmed milk because they pass from butter production. In proteins, dried buttermilk contains both casein and whey proteins. Dried buttermilk is a suitable alternative to dried milk for baking and cooking in kitchens. Dried whey almost does not contain any casein proteins but contains much more whey proteins. They are called whey proteins because during cheese production they are almost impossible to capture and remain in liquid whey. Whey also contains a lot of lactose (milk sugar), many minerals, and has a low fat content. Therefore, it is a suitable raw material for preparing drinks for everyone, especially athletes, because whey proteins, besides being easier to digest, promote muscle growth. Whey itself has a mild taste, so when re-mixed with water, we recommend flavoring it with something, for example, blended fruit.
We are glad that you supply these valuable foods in consumer packaging and believe they will find many loyal customers.
