Triple Brewing and How To Go Forth and Multiply

Something we've been doing for quite few years now is triple brewing - not brewing tripel, the Belgian strong blond ale as in Westmalle Tripel or Chimay White - but simply doing three brews consecutively into one fermenting vessel. If one's brewlength (the amount of each brew, i.e., 30 barrels) and FV capacity are the same then there is no need for such extravagant behaviour, however if one has a FV thrice as large as the brewlength, then doing three brews consecutively into said FV will work effectively. The brews can go in three days in a row, which what we do currently with Bigger Bertha (its other name being CT7)  shown below, or straight after each other, without a break, if one is shift brewing around the clock. The first at 8am, the second at 3pm and the third at 10 pm.

Our regular brewlength is 30 bbls (barrels) or in metric speak, 50hl (hectolitres or 100 ltres). We have 4 sizes of FVs - 20, 30, 60 & 120 bbls which means most of our brewing is in 30 bbl aliquots. The two smaller 20 bbl FVs get  brews of 20 bbls and the 30 bbl FVs get the standard 30 bbl brewlengths. But for the two larger FVs (FV8 at 60 bbl and CT7 at 120 bbl, the latter revelling in its status as a dual-purpose vessel - fermenting and conditioning) the dark arts of double and triple brewing must be practised. Those of you with a mathematical bent will be asking yourselves why we don't do quadruple brewing into the largest tank being of four times our standard brewlength of 30 bbls. The answer is we need some freeboard or space above the fermenting wort for the yeast head to rise up. And indeed it does. Especially with the stronger beers. For Blackfriar, our 7% Scotch Ale, for example, we'll brew 3 x 20bbl brews into FV8 and it likes to foam up with serious intent. 

I was reminded of this today by our summer placement student from Heriot-Watt University, Liam, who asked how much yeast we pitch into a double or triple brew. A good question. We pitch 10 litres of yeast slurry to give 18 million cells per ml of wort for the first brew of 30 bbls which is oxygenated for 30 minutes. As the cells take up the nutrients and the oxygen present in the wort, the yeast cells multiply sufficiently to be able to cope with the next brew coming in. This second brew only gets 10 minutes of oxygenation, which allows the now-multiplied yeast to grow even more to be able to ferment the doubled brew in the FV and also, after the third brew is added without any oxygen, to continue the fermentation to completion. A simple tale of yeast going forth into the fermenter and multiplying.

Lia Fail yeast head getting going in style

It's important to get enough yeast cells to ferment out the wort but we don't want too many otherwise the beer will have the wrong flavour, and beer is all about flavour. Having the yeast multiply, generally fourfold during a fermentation, is good for our flavour characteristics, and it's also a lot easier and simple to pitch 15 litres into a brew than 60 litres. 

As far as yeast vessels are concerned, we use simple 25 ltr drums into which yeast is run, merely by opening the valve and letting the yeast slurry flow in gently, from the bottom of the cone of an FV of one of the previous week's fermentations.

The drums are stored in a fridge at 3 degrees C where they sit until needed for brewing over the following 6 days. I wouldn't really want to leave the yeast in the fridge longer than a week as it will begin to lose viability and vitality quite rapidly after then. Pitching involves the yeast being pumped into the FV in-line with the oxygenated wort using our yellow peristaltic pump shown below. 

This pump from the peristaltic experts, Watson-Marlow, works like a hand milking a cow, gently squeezing the milk down a teat into the milk-bucket, by gently squeezing the yeast through a flexible hose (the clear hose coming out of the right-hand side of the pump) into the fast-flowing wort coming from the heat-exchanger and thus into the FV, getting good mixing with the wort in the process. 

Our pitching set above, where wort travels along the green hose and the pale beige yeast slurry is coming in from the left. We find this method of pitching gives consistent results in fermentation and flavour and it certainly beats opening up a fermenter lid and pouring in 15 litres of slurry and helps avoid infections from wild yeasts and bacteria which will do no good for the taste of the beer. And what we're all about is, of course, the taste of the beer! Like in this pint of Thrappledouser...

Slàinte! Ken

Out with the Old - In with the New...

We had a few wee tears welling up in our collective eyes this morning, as our old 10-barrel brewery - mash tun, copper, hot and cold liquor tanks together with 3 FVs plus assorted odds and ends - was loaded on to the lorry above. Destination South to Paul at Northumbrian Real Ale, whom we wish the best of fortune and fun brewing great beer on what was really good kit for us. We did over 2000 brews on it over 12 years before we outgrew it and got to know it all quite well. But nothing stays the same, so we're getting ready inside the brewery to commission our new 120 barrel conditioning tank below (CT7 at the moment) which is being constructed up in Drummuir (in a former distillery, by the way) by the same folk who made the FVs on the lorry above. The dimpling on the sides forms part of the cooling jackets, which will enable us to keep the maturing beer cold, but they'll be hidden by the 50mm of insulation and a thin stainless steel outer skin.

So here's a toast to the old and a welcome to the new!

Slàinte, Ken

Student Daze

We've had a young brewing student, Liam, from Edinburgh's Heriot-Watt University, over the last two months learning about brewing at the coal face, far away from the Hallowed Groves of Academe and the Search for Enlightenment.

He has been accompanied by young Czech brewing student Alesh Potesil, below, from Pivovarsky Dum in Prague, for the past three weeks, in learning the ropes in a production brewery specialising in ale, unlike the pilsner beers he knows well.

Chez Inveralmond, the daily quest for wisdom is relatively simple, yet complex: for example - how to get the young beer from fermenter into conditioning tanks and with which hoses and pumps and which bit goes where without having a beer fountain (much more fun and funnier than that of chocolate - if it's someone else's doing) or getting the wrong hoses connected to the wrong tank, thus leading to very grim-faced head brewer and an ashen-faced student.

Therefore the motto here is similar to that of carpenters, measure twice, cut once. In our case, check route of beer twice, then open valve. Liam has been doing a grand job and is discovering that practical brewing, as opposed to higher level microbiology, is very much rooted in common sense and maintaining high standards of physical awareness - e.g., where will that cask roll off the pallet and on to whose foot; how best to bang in cask tap with a mallet without the afore-mentioned beer fountain; holding a heavy beer-filled hose with left hand and connecting hose nut on to valve thread with right hand; listening to the cooling pumps to check all is in order; etc etc.

Alesh, in his turn, has been discovering the joys of infusion mashing with fully-modified malt (without the typical decoctions and multi-temperature mashes with under-modified czech malt) together with our crazy (in his eyes) temperatures for fermenting the wort (18.5 instead of 8 degrees C) and maturation of one week for ale unlike the two months he's used to.

It's vital in the brewery to have an understanding of the science of brewing, but equally it's essential to have an understanding of how beer works, as a beverage, as a social relaxant and convivial accompaniment as well as how the art of making beer enhances our lives and does its small bit in improving the human condition - in addition to getting the process right!

Having the opportunity to take on a student every year is great for us and them as they can learn more practical brewing and management skills in 2 weeks with us than 2 years of textbook study. And we can learn about the latest trends in music, how an ipod works and which nightclubs to avoid...or not!

Slainte, Ken

The brewery's getting bigger!

We are very proud and pleased to announce the commissioning of our new Fermenting Vessel, Big Bertha, which is dwarfing the lovely Lady Arlenka on her Sunday visit. Big Bertha holds 60 barrels, 100 hectolitres or 20,000 bottles. She was a bit troublesome to get in position, with 2 cranes needed and lots of excited brewery folk watching from the viewing platform upstairs.

However she's all ready to brew into with 60 barrels of Blackfriars destined for Alko in Finland! Hurrah!

Slainte, Ken

It's a Foam Party!

I thought I'd show you a few photos taken inside FV6 last week at the start of the fermentation of Ossian brew #2166. The above picture was taken 2 hours after the wort was all in the tank - you can see the yeast head staring to cover the surface of the wort.

1 hour later and the stiff peaks of the yeast foam start poking out.

Another hour gone by and the whole head of yeast is looking like the Cuillins.

3 hours after the first pictiure and the Cairngorms are about to climb out of the fermenter! Shut the lid quick!