Created in March, 2014, Sour Beer Blog is a website devoted to sour beer education, brewing, and celebration. To support the site and continue to provide new content, we also run a small online shop which sells sour beer themed merchandise. Our primary author, Matt “Dr. Lambic” Miller, is a brewer, freelance writer, and consultant on all topics sour beer related. We recently created a start-up sour beer news and media service which tweets @sourbeermedia. If you need to contact us for any reason, please do not hesitate to do so!
Hi Matt, I really enjoy your blog and interviews. I have a question for you!
I am looking at adopting the german process of using Saurgut (Sour Wort) to make ph adjustments (instead of lactic acid) before souring with mixed fermentation. Simply for another level of complexity. I keep a sour wort going by constant feeding. This has being working well for me already, but now I want to use it with some high plato beers. I don’t want to dilute the wort, so I was wondering if there would be any problems with keeping alive a high gravity Suagut going (1.085). I have tried it, and the lacto (Planatarium) does work very well with it, but my my question is more longterm, would there be other microbial problems from the keeping such a high sugar content wort active?
Thanks so much!
Bill
Hi Bill,
Thank you for your compliments on the blog and interview!
There is some evidence that certain strains of Lactobacillus are inhibited in their growth by high gravity worts, but I think this is a very strain dependent issue. In my experience Lactobacillus plantarum has no problem creating aggressive acidification of worts up to 1.065 SG. I have not attempted anything higher than this, but that has simply been to personal preference rather than an imagined process limitation.
In my mind, the most difficult aspect of maintaining any acidified (but unattenuated) Lactobacillus wort would be preventing contamination by wild yeast over several generations of handling and transfers rather than contamination from other unwanted bacteria, most of which would be inhibited by the low pH of the wort. If you find this to be problematic, I would simply suggest starting with fresh cultures every couple of generations.
I hope this info is helpful.
Cheers!