Organic milk is popular - sales were up about 15% in the last year.
Now shortages are being seen in several parts of the country some stores are having trouble keeping it in stock and posting signs apologizing for empty shelves.
The reason for the organic milk shortage is not how much people are drinking - it's the cost of what cows are eating.
Organic farmer Clifford Bruner says his cows can only eat crops that have never been treated with pesticides.
That makes the organic feed much more expensive - up 40% in the past year.
Because of the high cost Brunner and organic farmers across the country are forced to cut back on the amount they feed their cows.
And the less a cow eats - the less milk they produce.
Brunner's bottom line is about to get a boost.
He produces milk for organic valley.
In March the company will start paying farmers more for their milk .
But that will mean higher prices at the store.