I have been meaning to run some experiments for Year of the Sour Mash to determine the optimal medium to grow Lactobacillus, but it seems I have been beaten to the punch! Sam over at Eureka Brewing recently published an excellent writeup on evaluating starter media to propagate Lactobacillus that is far more comprehensive than anything I would have been able to produce. Take a look and I will share my thoughts below.
What I want to share today are the results of an evaluation experiment I performed a couple of months ago to look for MRS media alternatives to propagate lactobacillus at home. MRS media is kind of the golden standard used to propagate lactobacillus. It works very well but with the disadvantage of being a quite expensive media. I therefore tested a couple of cheaper alternative media and compared the growth/propagation efficiency with MRS.