Should I be concerned about possible bottle bombs?

[Calder]

When I brew a sour, I start with a large batch, and split it into 1 gallon (Imperial gallon) demijons for long-term storage in the crawl space. Why? Because I have lots of them, and they are easy to move around in the small space.

Three weeks ago I bottled 3 gallons of Lambic style and 1 gallon of Flanders. To each gallon I added about 5 ozs of beer (~2%) from a new batch started with Roeselare to ensure there was some live yeast in the bottles.

I didn't really think about it until now, but the Lambic Style beer was 1.011 at bottling (after 28 months), and the Flanders (33 months) was 1.008. These were brewed with my 'House' sour blend, which was made from dregs from various bottles, mostly JP dregs. The beers were certainly sour.

My question/concern. What is the chance the new/different bugs introduced with the Roeselare will work on any remaining sugars, and over-pressurize the bottles?

These beers were certainly sour. Lactic acid is heavier than water. Is it possible that the high-ish gravity is due to a high level of Lactic acid, and not sugars.

I bottled some of these same two batches a year ago, and the gravity was the same (within .001) as I measured this time.

 

[dantheman13]

I don't think there is a concern of the Roeselare bugs fermenting out the residual sugars. I don't have any experience doing this, but as long as the older beers had Brettanomyces, you should be fine. The 5 ounces of young beer may add a bit to your carbonation though. Overall I think you'll be fine, but you might want to crack one of each open in a month (few days of chilling first, of course), just to be on the safe side.

Interestingly, I asked Sean Terril about something like this recently in regards to final gravity readings and lactic acid (end of page 2 on the comments): http://seanterrill.com/2012/01/06/refractometer-calculator/