Top Cropping Vs Bottom Cropping: Pros & Cons?

Looking for some advice on weather to top crop or bottom crop my hefe. I just brewed last night (wyeast 3068) and at +12 hours I have crazy fermentation on my hands making it clear that I need to build a blow off tube setup. I have been planning to harvest (and save) yeast from this batch because it is a 2 hour drive for me to get liquid yeast and constructing the blow off tube will allow me to build a setup for cropping the yeast. I have read up on the board here and I have a few questions:

1- would bottom cropping the yeast be effective since this particular strain has low flocculation?
2-bottom cropped yeast is dormant and top cropped yeast is active. do I need to make the top cropped yeast go dormant, if so- How?
3-is there any particular advantage either method (assuming that you have a yeast strain that is suitable for both top and bottom crop)?

Do a search of the forum. There's plenty of information around here about harvesting yeast and just about anything else you might have a question about.

I'd suggest bottom cropping. It usually provides higher flocculating yeast, more yeast, and it works for me. Check out this sticky: https://www.homebrewtalk.com/f163/yeast-washing-illustrated-41768/

One way Top-cropping is useful when collecting from a higher gravity beer, as the yeast will be strained after fermentation has completed, and therefore not ideal for harvesting.

(1) There's nothing wrong with bottom cropping a hefe. Yes, you'll be getting more flocculant yeast but, in any hefe, you want 99.9% of the yeast to flocculate out anyway.

(2) Add the top-cropped yeast to boiled, cooled water and then refrigerate it. The lack of nutrients and oxygen will put the yeasties to sleep.

(3) Top cropped yeast are all alive, and are all active. If you can transfer it directly into another batch, it's ideal. Bottom-cropped yeast includes stressed and dead cells, is inactive, and includes trub that you have to wash off. That's why I top crop.

On the other hand, top-cropping a carboy (as opposed to a bucket) is a b!tch of a time.

Yeah I got about 50 ml of top cropped yeast that I saved. it's in the fridge now and I'll mix it with some water tonight and split it into 2 tubes. I'll maybe mix it with some bottom cropped stuff when I pitch. I dunno, still working out the best method.

I have to say that top cropping was super easy using this method :
http://www.aleiens.com/video/top-cropping-yeast-from-a

I built my setup using a mason jar and some grommets I got from an auto parts store. I had a powerful krausen though and without that I don't know how it would have worked.

I'd post pics if I could, maybe tonight via picasa or something

So, having done both a top crop and a bottom crop I can happily report some findings. Top cropping a carboy with 3068 was really easy. I built a similar setup to the link above and it worked like a charm. I like this method best because I didn't have to wash much so I ended up with a smaller volume to store. I'm using Sarstedt 50ml centrifuge tubes that I got from a lab supply place in town. This method was extremely easy because I did not have to separate the yeast from the trub by washing.

Bottom washing worked well but required more sanitizing steps, more boiled/cooled water and generally more work. I also ended up with a larger volume to store.

my guess is that the top cropped yeast will have a higher cell count, but I don't know that for sure. obviously the blow off tube top crop method only works with certain yeasts, beer styles, and fermenters.

So, having done both a top crop and a bottom crop I can happily report some findings. Top cropping a carboy with 3068 was really easy. I built a similar setup to the link above and it worked like a charm. I like this method best because I didn't have to wash much so I ended up with a smaller volume to store. I'm using Sarstedt 50ml centrifuge tubes that I got from a lab supply place in town. This method was extremely easy because I did not have to separate the yeast from the trub by washing.

Bottom washing worked well but required more sanitizing steps, more boiled/cooled water and generally more work. I also ended up with a larger volume to store.

my guess is that the top cropped yeast will have a higher cell count, but I don't know that for sure. obviously the blow off tube top crop method only works with certain yeasts, beer styles, and fermenters.