EDIT: Crap, it appears I mislead myself. Northern Brewer includes a temperature range of the particular Wyeast you are using, and I assumed this temperature range factored out off-flavors. I read on this stackexchange that it is a good idea to let the temperatures rise after the initial 3-5 days of fermentation. I assumed this meant to the top of the temperature range specified by NB/Wyeast. My Belgian Ale I allowed to go roughly 78*F during the day times. My Cream Ale I allowed to go specifically 71-72*F nearly round the clock. Regardless, I enjoyed this discussion and learned something about yeast starters and temperature!
I have used a yeast starter for my last 3 batches. Two of these batches are bottle conditioning for carbonation, but I took two of them out to test a few days ago.
They were so full of esters that my neighbor referred to the first one as "Bananna Beer", and the second one as "Strawberry Beer".
One of the batches that I am annoyed about in particular was a Belgian Trippel that took about 6 weeks (+2 weeks bottle conditioning) and required a secondary, and was the most expensive extract I've bought so far. The other batch was a creme ale that took 2 weeks (+ 2 weeks bottle conditioning).
I've never had the fruity-beer problem because I've done a fantastic job at controlling temperature with a swamp cooler.
However, I can't use a mini-swamp cooler with my yeast-starters, as my home-made stir-plate can't hang.
1) Is fruity flavoring always and everwhere a side effect of high-temperature and ester production, or may sanitation problems also generate fruity flavoring?
2) If fruity flavoring is always and everwhere formed by high-temperatures, is it better to forgo a yeast starter if it is not possible to control the temperature of the yeast starter? I also figured that maybe a 12 hour yeast starter at night time would be better than 72 hours in higher heat.