The Double Drop - traditional British method.

This used to be a very common method of brewing in the UK, Fullers did it until they got their new vessels a couple of decades ago, and some still do it such as Brakspear (at Wychwood). The idea is to start the fermentation in an upper vessel then, after 16 hours drop the fermenting wort into a lower vessel, leaving behind unwanted proteins, hop materials etc and also give the wort a good second aeration to promote a healthy fermentation. I read about this also in the new Jamil and White "yeast" book, so decided to give it a whirl. I couldn't really see that 16 hours was going to make all that much difference, but I'll try anything once, honey.

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 - 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:

Place on counter, spoon 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, during the rest I covered both FVs with starsanned lids. Stop 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, 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 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. 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 crud has been removed from the brew - amazing how it compacted down into a distinct almost firm layer at the bottom. I'm amazed that a mere 16 hours can produce such results. I can well see why the UK breweries used this method. If this produces a better, cleaner, faster fermenting ale I'll do it all the time from now on.

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Marstons in the UK sell a Double Dropped ale in bottles. The commercial description states:

The double dropping technique allows only the most vigorous yeast to survive and results in a cleaner fermentation process and a fresher, brighter beer. Double dropping involves "dropping" the beer during fermentation from one vessel to another, normally after 24 hours.

Its not a bad pint. Be intresting to see how yours turns out BB, no doubt it will knock spots off the Marstons brew, Post me a bottle and I'll do a taste test



Y

• • SVA Brewer With Over 50 Brews From Great Britain
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As usual, an excellent pictorial Bribie! (I also note there's a toucan stout headbanger on the books! )
Yes, the foam can get a bit outrageous before it is all transferred completely, either by this way or a daily thrashing with a slotted/ holy spoon.
One thing to keep when doing this sort of thing, in humid conditions drops of condensation form on the outside of the upper fermenter, then drip to a puddle under the fermenter which can also drip in the lower one over the edge of the table or bench. Obviously this is not an insignificant infection risk, however a towel or something absorbent can help capture it. Also, we have had hoards of flying bugs here of late, so I've been toying with the idea of using a transfer tube into the receiving fermenter with some film over the top. Without any precautions, invariably one thirsty bug will find its way into the fermenter and stuff things up. Aeration probably isn't quite as vigorous though and of course I wouldn't aerate after about day 2 of the ferment, then just leave it to go anaerobic.

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That is a nice write-up! Good on you BB

Will look forward to hearing what you think.

• • SVA Brewer With Over 100 Brews From Australia
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Brew is finally ready to drink. The fermentation went quite quickly - in the past I have gone for about 8 to 10 days with most yeasts and always get a bit paranoid when I read on UK brewers websites "primary fermentation is for three days then we rack to conditioning tanks for a further few days, cask and send out to the trade" etc. However on this occasion it was all over in about 6 days and I kegged / bottled straight out of primary.

It's ended up as a really typical UK ESB with a lot of late Fuggles notes and well attenuated - nice colour and chill hazed to buggery below 12°

However I think that's to do with what happened after primary - I normally rack into a cube with gelatine, flush the headspace with CO2 and cold condition in my lager fridge - that can take 3 cubes - for around 10 days, then add Polyclar three days before kegging / bottling and all my beers are almost crystal clear going into the keg. So much so that after two or three days carbing at serving pressure they usually pour bright as a pub beer.

Advantages of the double drop so far, seem to be:

• Shorter more active primary
  Better attenuation which is probably due to the better oxygenation (there's a graph in the new Yeast book which predicts this)
  Less yeast trub in primary with an extra bottle for me at the end.

I'm onto my second dropped brew now, and have a new temperature controlled fridge which enables me to crash down to -1° so looking forward to the results - kegging next Monday. This is a blonde ale so nothing to hide behind there

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