I just wanted to add that one the things I think every home brewer should do at least once is make a hefe wort and split it into 2 fermenters. Pitch the German Hefe yeast into one half, and an American wheat yeast (or Kolsch yeast) into the other.
You would never think it’s the same wort, but it is, and it shows exactly how much of your beer’s character is due to the yeast, and not the ingredients.
You can do the same with other yeast pairs, and see how even so-called “identical” yeast strains can prove to taste different in subtle ways.
It’s a great way to let you zero in on the fine differences between strains and also gives you a really good way to expand your taste memory.
It’s been a while since I’ve brewed a hefe (although I have one on deck later this week), but one other means to allegedly increase the banana (ester) character of your beer is open fermentation. I say allegedly, because while we know that hydrostatic pressure (i.e., fermenting in a tall conical fermentor under literally tons of fermenting beer) decreases ester production, that doesn’t necessarily prove that the inverse is true.
That being said, in my limited experience with “open fermentation” with certain yeast strains (WY1469 in particular), I have been happy with the ester profile in the finished beer. For me, “open fermentation” means leaving the lid off my fermenter during the early/active phase of fermentation. I place a sanitized paint strainer bag over the top to keep bugs and dust out, and seal the lid once the krausen starts to drop.
Not much unless SN’s fermenters are shallower than a homebrewers 5 gallons.
The real secret to bananna ester is the formation of Ethyl Acetate and Isoamyl Acetate. This is the “banana aroma” in Wheat Beers. Formation of these esters requires Glucose. During a regular mash only 10% of Glucose and 90% Maltose are formed. Look into a “maltase” mash for maximum Glucose, thus banana effect.