
I note that DD hasn't been mentioned on the forum for a while now, but some guys had problems with stuck fermentations. I guess that was due to yeast being left behind and not making it into the collecting vessel - in my exercise here I used a true top cropper (Wyeast West Yorkshire Ale 1469 - traditional Stone Square stuff) and skimmed yeast from the first part of the fermentation to add into the collection vessel. I'd probably be reluctant to use this method with, say, US-05.


I have brewed a red ale:
4500 Perle
300 Caraaroma
200 Carared
64 degrees 60 mins
18 Northern Brewer 60 mins
90 Fuggles flowers NZ 10 mins
No chill, pitched next day - Wyeast 1469 from previous yeast cake. I used my 25L fermenter to kick things off, around 24L in the FV. (note I slightly increased the brew length from my normal 23L to take account of the fact that some volume would be left in the 'top' vessel after the drop)
After 16 hours in the primary at around 17° we are getting yeast - actually a fairly firm layer floating, as 1469 tends to do:

Place the 25L FV on the counter, spoon off the top crop of yeast into a sanitized 30L FV and position it on floor below, starsan everything including tap.

Start the drop: I had to do it in two stages due to foaming, and during the rest I covered both FVs with starsanned lids. Stopped dropping when some turbid stuff started coming through.
If you look carefully at the bottom of the FV you will see a definite 'hard' layer of crap on the bottom, maybe the fermentation "curdles" it or something? It looks like all the cold break could be down there.


End result, a normal quantity of wort in the FV plus a jug of absolutely disgusting looking crud out of the first FV that looked like something you would pump out of a restaurant grease trap.


So now I've got a fermenter of cleansed wort with some pure fresh yeast in it, nicely aerated (twice) and bedded down at 19 degrees for the anaerobic phase. Can't wait for this one. I reckon the jug contains break and crap from the original bit of yeast cake as well. I'll top crop out of primary in a day or so for the next brew. Top cropped yeast is pure, as opposed to using sludge which as you can see contains a lot of unwanted stuff.
The main thing is that all that slimy stuff has been removed from the brew - amazing how it compacted down into a distinct almost firm layer at the bottom. I'm impressed that a mere 16 hours can produce such results.

