You may be wondering how milk exhibits different flavors. The secret is fat. The milk fat consists of a mixture of more than 100 fatty acids. Different fatty acids contained in milk fat, especially those short-chain and middle-chain ones, create a full body of taste. Three simple factors are related to milk flavor and additional nutrition: feeding, season and processing technique.
The first factor is how cows are fed. In the modern dairy industry, cows are fed mainly by fresh grass, silage, hay, grain, soybean meal and other concentrates; either in an organic way or not. Cows grazing freely on well-grown pasture give the best milk, because both grass-feeding and good aeration in the stall increase the pleasant volatile fatty acids in milk that enhance flavor.
Free grazing will largely reduce the cost on cow stalls, making the milk more competitive on the market. Furthermore, commercial pasture is highly productive. If properly managed, grass-legume sward can yield up to 1200 ton dry matter per hectare every year. Therefore, grazing is beneficial for farmers economically.
Grasses, like perennial ryegrass and tall fescue, together with legumes, like white clover and alfalfa, can create a grass-legume sward that offers cows a palatable and easily digestible meal. Herbs like ribwort plantain and chicory have more micronutrients such as zinc and manganese; they can also optimize the digestibility of grass-legume mixture, hence balancing the cows’ feed.
As a result, pasture milk has more short-chain fatty acids and tastes more refined than milk from cows fed by concentrates. Cows fed by pasture also give softer butter. Organic farming is a good choice because of the lack of antibiotics used on the cows, but it has little contribution to the flavor and key nutrition.
The second factor is season. If you visit meadows during late spring and summer, you would find all sorts of attractive flowers, which means grasses are in the reproductive stages with preferentially more crude protein, more crude fat, less fiber etc.. Higher quality of food will make the cows produce milk of higher quality. More precisely, they produce milk with high-quality fats.
Don’t worry about the word “fat”, most fats contained in milk are considered “good fat”. For example, the lauric acid digested from milk fat is a positive factor for your leptin, which can really make you slim. The conjugated linoleic acid (CLA) is another cutting-edge natural anti-cancer factor and only can be found in milk; other short-chain and middle-chain fatty acids in milk fat are friendly to the intestinal tract too.
Milk gathered during May and June has significantly more CLA, more lauric acid and more lactose which make it sweeter. Moreover, stronger ultraviolet light during May and July also improves secondary metabolism products in grasses thus broadening the spectrum of milk flavor elements.
The last factor is the processing technique. If you are a gourmet, you may also already find that milk tastes differently between brands. Micro-filter technique is the champion for retaining bio-active nutrition, freshness as well as sweetness. Pasteurized milk tasted lighter and softer than UHT milk. UHT milk feels thick and strong, and sometimes has an unpleasant “dull” mouthfeel.
Finally, all of these factors will be reflected by its price. Milk with a higher price has the advantage of better freshness and mouthfeel. Now, you may conclude that buying “Micro-filtered June pasture milk” will give you the best flavor. But please remember that all milk contains nearly the same proportion of protein and calcium, which give the fundamental nutritional value of milk. Just forget those advertisements. It’s fine to decide which milk to buy based simply on your budget.