I'm new to all grain brewing, did my second mash last weekend (which went much better than my first, although the first batch is still better than any of the kits I've done and it still has some maturation to go!) and thought I would have a go at some yeast harvesting.
The brew is Wheeler's London Pride recipe and I used a Wyeast Thames Valley 1275 smackpack (first use of a liquid yeast), which activated well and went straight into the wort with no starter. The fermentation started rapidly and thick and yeasty Krausen developed so after a couple of days I thought I would skim some off the top to experiment with more than anything, just use it to get more familiar with recovering yeast. (At the same time, I also added some spraymalt to a drained bottle from a previous brew to see what I would get out of that.)
With the thought of experimenting in mind, I thought I would mix the skimmed yeast with 300ml of spraymalt solution and put it in a bottle with an airlock. This fermented out quite quickly and left a decent amount of yeast in the bottle. I then decided to put this in a demijohn with another litre of spraymalt solution. This has nearly fermented out and has left about 3/4" of yeast in the bottom of the DJ.
I also transferred the beer to a secondary FV last night and thought I would have a go at rinsing the yeast left in the Primary. After several attempts at leaving it to settle (and refering to wolfys excellent thread and pics) I decided that most of what I had got was trub. There was a lot less sludge in the bottom of the FV than I have been used to with dried yeasts from kits and there seemed to be only a very thin layer of paler yeast on top of the trub after I had left the jar to settle overnight.
The questions I have are..
a.Does the Thames Valley yeast (or liquid yeasts in general) produce a more yeasty krausen than dried yeasts? I wonder if it was a yeast more suited to top cropping, or would it have eventually settled to the bottom of the primary FV if I had not transferred to a secondary FV?
b.Is it generally better to use yeast recovered by rinsing the FV for storing in the fridge for future brews? Or do you vary the harvesting method depending on what each batch does?
c.Is there any reason why I should not treat the yeast in my DJ as if I had split an original smackpack and so transfer it to smaller bottles to store in the fridge for future brews a la Jim's 'Wyeast splitting' method? I guess yeast is yeast whether it came from the top or the bottom, right?
d.Given that the bottle from the previous brew seems to be generating a decent amount of yeast (not that I plan to re use that one as it was the yeast that came with a kit) should I just step up from a bottle each time and not worry about harvesting???
e. Should I just stop obsessing with it and get on with drinking the beer?? (I think I know the answer to this one...)
Sorry for the mammoth first post!

Cheers!