I don’t think I’ve ever made any effort to hide my distaste for vertical extraction as a method of dispensing cask ale. Both the float and the pipe size are bad for proper cask conditioned beer.

And here’s why…

When an ale is conditioned in the cask, there is still live yeast in there that is continuing to clean up after itself; reabsorbing the esters its produced during fermentation and producing the carbon dioxide that we know as carbonation.This means that the inside of a cask of ale is a bit like a snow globe. You shake it around and it all gets mixed up, and then it needs time to slowly settle out again.

When a cask is stillaged on its belly, all that trub and lees settles into the curve of the belly, below the keystone area where the tap is hammered in. So when you pour a bit of ale through the tap you can instantly see if it’s clear and fully settled or if it’s still got some bits in and needs more time. But vertical extraction uses a float that sits on top of the beer, so when you draw some off to check if it’s finished conditioning and is clear, you’re only checking the top of your cask; further down it may still be full of bits as everything is settling towards the bottom.

The traditional beer pipe size is ½” (half inch), meaning that when you use a handpull to dispense the beer, the pressure in the line with a standard pull isn’t so much as to suck the lees from the belly of the cask and into the line to be dispensed into a customers glass. The modern trend is to use ⅜” (three eighths inch) beer line, meaning that when you use a handpull you’re sucking the beer into the line quicker, and increasing the risk of sucking lees in along with it.

I’ve experienced both these things in my time running cellars and a brewery. It’s not theory, it happens. So I’ve not liked using vertical extraction or using ⅜” line.

However this weekend I was explaining this weird holdout of mine to a friend (Caroline Debenham) who merely took a sip of her pint and said “That’s why you use a piece of straight syphon to test from the bottom when you use vertical extraction.” 

This has opened my mind completely. I have never seen this done, I’ve never seen it in training videos or literature, and I’ve never had any of the cellar folks or technicians I’ve chatted to about this suggest that it was even a thing.

But this one little thing solves both issues that I’ve got with modern cellaring techniques; and there are definite advantages to both vertical extraction and a smaller line size.

With vertical extraction you’re taking up less floor space in the cellar, and lifting casks less. The end of the cask is narrower than its width, and casks will stack. Admittedly some stack better than others and you usually have to stack them “pyramid style”, but you can still fit more casks into your cellar which is a bonus as the trend for a wider range of beers on offer still continues. And because you can stack them on top of each other, you don’t need the cask stillaging anymore – and the lifting of casks above waist height that entails. And with a smaller beer line, you have less beer in the line. Meaning both less wastage, but also less cooling needed. 

So that one sentence from Caroline letting me know how she gets over the issue in a way not covered in any of the instruction manuals I’ve read, training videos I’ve seen, or cellar folk I’ve talked to, that one sentence has completely changed my mind on the use of vertical extraction and ⅜” beer line.



I’ll almost certainly get comments on this article, both here and offline saying “Well, of course you do that” but all I’ll say to those is “If that’s the case, why isn’t it in the literature? Why isn’t it in the training videos? Why have you never said this when we talked?”  We need a lot less knowledge gatekeeping, a lot more talking, and a lot more learning new ways. See, even I can learn new things.