Stressing Yeasts For Flavors

I'm going to be brewing a wit and hefe soon and was wondering if I should make a starter for them. I'm going to be using White Labs yeast for each of them. I've heard some of the stresses put on the yeast by the underpitching can help to produce esters, which may not be a bad thing for these styles. What do you think about this? Would I ruin it without a starter?

You won't ruin either of these without a starter, but if the OG is over 1.060 a starter is a very good idea. Since each yeast has been selected for the style, you don't need to stress them to get the expected esters.

For my wit, I do a 1L starter the morning of brew day and pitch it into the beer about 8 hours later. This is definitely better than pitching direct from the tube since the yeast will be active and there will be some growth which reduces the lag time considerably.

Another thing that will help improve ester production is to do an open fermentation. In a bucket you can accomplish this by simply putting a solid bung in the airlock hole and loosely fitting the lid over the fermenter. In a carboy, just cover the neck with aluminum foil. Once fermentation slows, affix an airlock as usual.

do not underpitch. More damage can be done from underpitching then can be gained. Pitch the proper amount and the yeast will make great beer.

If you really want to mess with ester production use the fermentation temp. Wheat yeasts do all sort of different things at different temps. ferment one at 66, one at 70, and one at 74 and you will have 3 very different ester profiles. I think most people prefer the colder fermentation.