Why does my milk taste different than I remember?

Yesterday I had someone reach out because the milk they had received from us did not taste the way they remember it tasting at the end of last season. They said it tasted “sour and very different from the other [milk] we’ve bought before,” and “It smells fine but the taste is off. I’m curious if I should pour [it] out?”

Needless to say, it made me nervous as I never want bad milk going out and I’m scrupulous with how I handle the equipment and milking process, plus it was less than 24 hours old. So, I went and found a bottle from the same batch they had received from us and tasted it. It was delicious and tasted like fresh goat milk, but she was one hundred percent correct in that it did not taste like the milk she remembered from October/November.

In our brief messaging back and forth I did a poor job explaining why the milk was different than what they remembered so I wanted to take a moment to put it a little more clearly and I felt like it would be worth sharing, which is why I’m posting it here.

Like everything that comes directly from a farm, milk is seasonal and individual and the milk from every goat tastes slightly different and it changes throughout the year. Before we started milking goats with a machine (which mixes all the goats’ milk together in the milking process) we would often have the milk of an individual goat in each bottle and I could tell which goat gave it by the taste of the milk. I had some I preferred for drinking and others that made better cheese but it was all still good, delicious milk.

We send our milk off for testing each month and it shows how the fat and protein levels for each goat are different from each other and also change over the course of the lactation. Early in a goat’s lactation it has a lower PH (more acidic) and over the course of the lactation the PH increases and the acidity drops, thus a slightly sweeter milk.  The amount of lactose along with the types of proteins and their concentrations change. Even fat particle size and its ability to homogenize into the milk fluctuate. Also, what the animals eat changes over the course of a year which also affects the taste and chemical makeup of the milk. When they’re on pasture is different from when they’re getting fresh hay to now, when they’re getting last year’s hay.

This is why there are certain cheeses that are only made in the early or later part of lactation or depending on where a goat is in her lactation you change the amount of culture or rennet you use in making cheese.  The chemistry of it is actually quite fascinating and being able to observe how milk, cheese, or any farm to table product, changes over a season or all the seasons is a wonderful way to stay connected to the natural rhythms of life.

Jumping back to the original question about the milk tasting sour- It makes sense considering that sour milk and early lactation milk have something in common in that they both have a lower ph. As milk goes sour the bacteria (or culture, if you prefer) increase and convert the lactose (sugar/sweet) to lactic acid (sour) thus we have taught ourselves that if we notice an acidic nature to our milk it must be going “sour” which often equates to spoiling. However, when you have the opportunity to experience milk over the course of an entire year and you experience these natural changes in flavor you begin to understand that this slightly acidic twang that we associate with bacterial growth can also just be part of the natural cycle of the lactation process.

The person who kindly brought this to my attention just started getting milk from us in August of last year so they experienced the last third of the lactation cycle when the milk was the least acidic and the goats were still out on pasture.

So yes, the milk does taste different, but it’s supposed to.

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