Originally Posted by sweetcell
doesn't it depend on the strain of lacto? aren't certain ones more tolerant of hops and alcohol than others?
Lacto is fairly alcohol tolerant; most strains do fine upto 8-9%/vol. The heterofermentive ones (e.g. the ones that make both lactic acid and ethanol) wont ferment on their own past 2-3%, but both hetero and homofermentative lacto's maintain some souring capacity in beers with higher alcohol contents. The major thing that limits their activity is not alcohol, but rather the availability of fermentable carbohydrates. As you may expect, this can be limiting in beers where yeast have consumed most of the sugars. Many strains of lacto can eat cellbiose, which is why you can get on-going souring in barrel-aged beers. Using oak cubes may provide a similar capacity in the home brewery, but I've not tried this myself and therefore cannot comment on how well it works. As a rule, lacto added to a fermented beer in glass or plastic will not do well due to the lack of suitable carbohydrates.
As for hops, susceptibility is highly strain dependent. Most of the commercial ones are highly sensitive to hops. I (and many others) have isolated hop-resistant lacto strains. I'm still assessing the ones I've found (the first two produced some pretty unpleasant off-flavours; I've got 8 more to test), but others have reported success finding hop-resistant lacto's that produce nice acidification of beer without other undesired off-flavours. I believe the mad fermentationist has had success in this regard.