Homemade buttermilk 自家製バターミルク

 For the last couple of weeks we have not been able to get buttermilk particularly the brand my wife likes best. As was the case when we could not get plain yogurt at the start of the pandemic and my wife started making it, she decided to start making buttermilk too. So she ordered buttermilk starter from "Cultures for Health" (the same place she got the starter for yogurt). Unlike yogurt, however, there is little information on the internet on how to make buttermilk. Most of the entries are about what to substitute in recipes for buttermilk if you don’t have it. 

Digression alert: Buttermilk is one item that is very difficult to find or not at all in Japan even recently. When I was growing up in Japan, I never heard of it. Even in the U.S., not many people will drink buttermilk but almost exclusively use it in cooking, especially baking. It has its own unique tangy flavor which will add to the flavors of baked goods and its acidity will activate baking soda. My wife is one of the rare people I know, who enjoys drinking buttermilk. (She says, 'What's not to like? If you like sharp cheese why not buttermilk?') Originally buttermilk was the residue liquid after butter was churned. It was fermented to make buttermilk but modern buttermilk was made by inoculating and fermenting whole milk as my wife did (see below).

The resulting buttermilk (shown in the first picture) was quite thick and almost the consistency of runny yogurt but it has a very different taste... tasted like...buttermilk…actually pretty good buttermilk!

 

To make buttermilk

To “wake up” the culture when you first get it. 
Pour 1 quart of pasteurized milk into a glass container. 
Add 1 packet of starter culture and mix well. 
Cover the container and put in a warm spot (we use the proofing box) at 70 -77 degrees. 
Check after 24 hours to see if the buttermilk has set. If it has not leave it up to 48 hours checking every so often. 
Once it has set refrigerate at least 6 hours. (We put the container in the proofing box at 9:00 am on Friday and took it out at 8:00 PM on Saturday.) 

For subsequent batches add 1/4 cup of the previous batch to 1 quart of milk and repeat the procedure of putting it in a 70-77 degree proofing box until set. It should set in less time than the first batch, about 12-18 hours. While doing subsequent batches I realized the milk was very cold just coming out of the refridgerator and it took some time until it even reached room temperature in the proofing box. So I gently heated the milk to about 90 degrees in a pan on the stove. When it was about room temperature i.e. just warm to the touch,  I added the starter. This really accelerated the process. If the milk was started at 7:00 AM it was ready by 7:00 PM. The instructions suggest making a new batch every 7 days to keep the culture strong. It also suggests that it may take several batches for the flavor and texture to even out. 

The resulting buttermilk from our first batch, was very thick and creamy. It had a very mild flavor and even I was able to drink a little of it.