Beer Forum

Using the Wyeast Rosilare blend, how long does it take this stuff so sour a beer, march will have be 2 years and not even a mild hit of sourness

depends on the beer

You should be fairly sour by 2 years. But March is still a bit off. Keep in mind that as good as that commercial blend is, it still is fairly tame and can benefit from the dregs of additional sour beers added to it. Your final gravity achieved prior to the brett and bacteria "really" working on it also makes a big difference with regards to residual sugars and dextrine that the bugs will have a chance to convert into acidity and funk.
For example, you will have better success if the bugs have 1.020 gravity vs a 1.004 gravity points to do their thing with. Both mash temps and/or crystal/cara malts can help this issue when creating your wort.

My advice at this stage in the game would be that if you desire more acidity and funk, then you should get ahold of some commercial sour beers that you enjoy the flavor profile of and are known to have hearty viable dregs. Pitch 2-3 bottles worth of the dregs directly into your secondary fermenter and allow to age another 4 mos prior to taking a gravity reading and sample. The addition of the dregs will help to speed up acid production and provide more depth and complexity than the Roselare strain can do on its own.

I know little to nothing about sours, but in the case of pitching more dregs into the beer, would it be useful to add some additional food to the mix so the bugs have something to work on (assuming the current beer is well attenuated)? I'm thinking a bit of maltodextrin or maybe even a simple sugar (sugar, honey, etc)?

Do you get different souring speed/type if you use simpler or more complex sugars (even to the point of having turbidity from starches)?

its an oud bruin style OG was about 1.062 or so been a while and ive added 2 pounds of cranberries to it over time

What is the current gravity at?

If it is low, it can be a good idea to add in some boiled/chilled maltodextrin to provide the bugs with some additional dextrins to work on that are more difficult to consume. Making them work harder is always beneficial for your sour brew. Boiling up maltodextrin is a huge PITA as it boils over very easily and is a b***h to get out of the pan once it has cooled.

sampled it yesterday its slightly tart and at like 1.004 ish. may add another pound of fresh cranberry purée

I would let it ride after your addition of cranberry puree. I would think that the puree alone should most definitely add some acidity even just from the fruit. I would also suggest that you add the dregs of 2 commercial sour beers (i.e. Russian River, Jolly Pumpkin, Crooked Stave, etc) along with the puree addition. This should help to increase the acid production and hopefully speed up the timeline for you.