Several weeks ago I asked if there were any dry commercial SD yeasts available. Red Star popped up and after unsuccessful attempts to locate it in my area, I ordered a free sample from RS. I made a batch following the instructions, which are fairly simple. The results were less than desirable, at least for me.
Mixing the yeast with water (step 1) produced the most vile odor I can remember. The dough didn't smell much better. After baking, the bread had a decent crust but of an odd color, sorta like gray/brown. The crumb was dense. My wife thought it tasted a bit sour, but I couldn't detect it. Overall, not a very good loaf in my opinion. I can't recommend it, but your mileage may vary.
Thanks to Red Star for sending the sample.
I have not read where anyone thought it was good. Mother Nature wins again...
Thanks for the report, Old Baker.
Far as I understand, what gives sourdough its flavor is the bacteria cultures, not the yeast -- you use wild yeast just because it's tough enough to handle an acidic environment.
I think the RS SD product contains both yeast for rising and bacteria to give the bread a sour flavor. The only place I have found it is on Amazon. It's a dry granular product that makes one batch of dough (two baguettes). But at almost $4/packet, it's too pricey for me. My limited success with SD bread resulted from a starter that Dan Ayo generously sent me. I've nursed it along to the point where it worked well.
I was in Germany last month and looking through the breadmaking aisle in a supermarket (as you do!), I spied a liquid sourdough product. It comprised 2 plastic pouches in a pack, maybe 200ml in total.
I think it said it was enough for 1kg of flour, but you had to add yeast as well, so I reckon it was probably a "dead" culture designed to impart a sourdough flavour, without any leavening ability.
On that basis, I gave it a miss!
Lance