A few weeks ago I posted about stepping up my Brett cultures by reviving older pitches from previous ferments as well as culturing new ones and getting pitches of new stuff from my buddy, Stephen. At the same time I was working on culturing up Lacto from 3 different sources as well. Stephen and I had split a Cascade Apricot after dinner on April 7th; he took the bulk of the dregs and I kept a few ml of slurry from the bottle. His was pitched directly into a small wort starter (1.020 @ 300ml) that he had brought with him, and was left at room temp. I put mine into about 250ml of Lactose sugar starter the next night and kept it at around 95*F. I ended up taking this starter and mixing in apple juice to bring it up to 750ml of liquid. I also added some Zoi Greek Yogurt to a jar and hit it with 750ml of apple juice too. The third source was some pale malt I had in the garage which I added to to the last 500ml of apple juice. I placed all of these in the ferm fridge wrapped tight in my heating blanket and kept them at 105*F for a week. I sampled once or twice to see if I was getting any activity. On brewday I was going to pitch some of the starters into my Saison along with 2 Saison yeasts and the Bretts. I went to taste them and nothing. Not a trace of Lactic acid. I am thinking that my pasteurized apple juice must have contained sulfites as opposed to heat pasteurization (I swore I checked that though), thus inhibiting the growth of the Lacto in all 3 starters.
Luckily my buddy still had his 2 week old Cascade starter which he said was quite tart, and offered 200ml to me for my pitch which I used 150ml of and kept the other 50ml to grow up for myself. This new starter of mine spent a week in the ferm fridge with the fermenting Saisons on 250ml of last runnings from the brewday, and had gotten quite sour. I pitched around 100ml of the starter into my Oud Bruin from this time last year to get it to sour up, and then added the remaining 50ml (after sampling and such) to a 500ml 1.020 DME based starter for further growth. It is back in the ferm fridge with the Saisons in the mid 80*s souring up nicely.