Tuesday, 30 September 2014

Thornbridge Competition

After driving to Bakewell and dropping off my Vienna IPA entry into the National Home Brew Challenge, I figured that most likely it would be the last I'd hear about it. Being a rookie home brewer, only in my wildest dreams did I harbour thoughts of actually winning.

Obviously I'd tried the beer before entering - it was clean and tidy, I was happy with it and in all honesty, I had felt that it may do okay. I always believed though, that there was bound to be a few absolutely stand-out entries and that one of these would inevitably triumph.

It came as a bit of a surprise then, to find a missed call and voicemail from Thornbridge's Alex Buchanan one day in mid-August, asking if I could call him back. It could only really be one thing, so I shakily dialled and spoke to Alex, who said that after much deliberation, my beer had come out on top!

Since recovering from the initial shock, it's been a fantastic experience to be involved in helping Thornbridge's brewers scale up the recipe and make the beer. I discussed the recipe via email with Rob Lovatt and visited in early September for the brew day.

Receiving my certificate and cheque

The kit at Thornbridge is bigger and more automated than in other microbreweries I've helped out at. They have a 30 barrel plant with separate mash and lauter tuns, a copper and a Rolek Hopnik.  Add 18 conical fermenters and it's quite a setup. The brewers were unfailingly friendly and helpful and it was good to put faces to names. James Buchanan took me off for a tour round the old brewery and the grounds of Thornbridge Hall, including the statue of Flora, a photo of which adorns every bottle.

Walking under some of the fvs
Flora, Roman goddess of flowers

The grain is delivered to silos in bulk so only the speciality malts and the hops are handled manually. All the vessels have clean-in-place (CIP) systems so this frees up the brewers, allowing them to focus on measuring and monitoring rather than wearing themselves out shovelling used grain around and cleaning up.

The whole process is managed from a pc in an air-conditioned brewing control room. On its monitor, this shows a schematic of the brewhouse with quantities, temperatures and other critical information displayed alongside each vessel. A click of the mouse is all it takes to start each part of the brewing process. Behind the control room is a laboratory, where the brewers take samples to be analysed at certain points in the brew.

Will Inman checks the pitching rate of a batch of Halcyon

Every brew gets tested for limit of attenuation, dissolved oxygen, pitching rate and a host of other variables and it's this culture of constant quality monitoring that in my opinion sets Thornbridge apart from most other UK micros.

Rob stuck to my recipe as closely as he could, making changes where necessary to allow for their different kit. A small bittering charge of T90 pellets was added to the copper at the start of the boil and a 6 grams per litre (30kg) charge of Columbus, Citra and Ahtanum was put into the Hopnik. This is a vessel through which the hot wort is circulated after the boil is finished. It's the most efficient way of getting the volatile hop flavours and aromas into the beer and much of the bitterness is derived here as well.

Once brewed, the beer was left to ferment for a week and condition for a further two then I visited again later in September to see it being bottled. The beer tasted fantastic - a flavoursome, amber-coloured IPA with the big Columbus and Ahtanum aromas particularly evident. I've recently developed a bit of an obsession with looking at the best before dates on beer so it was a privilege to sample some within minutes of it being bottled.

I could tell it was the same recipe as my home brew but as I expected, Thornbridge's superior processes and their attention to detail had taken it to the next level. There were a few little things I would have changed about my brew and Thornbridge had done it. This was the beer I was trying to make - ten thousand bottles of it!

That just over two months after driving to Bakewell with my entry, I'll be able to go into Waitrose and buy a bottle of the beer with my name on the label, made to my recipe, is pretty amazing. I hope the beer is well-received by the Waitrose customers and I'd like to extend my thanks to all involved in organising and running the competition.

Having a well-earned beer back home

Monday, 8 September 2014

Brew 18 - Divine Hammer

10.5% Triple IPA

Brew date 28/7/14

This was my first attempt at making a really high strength beer and it was a special request, with the finished result destined for my mate Nick's 40th birthday weekend.

I wanted to make a big double or triple IPA, with multiple dry-hop additions and dextrose in the boil, to boost the ABV while keep the body light. I called the beer "Divine Hammer" after the song of the same name by excellent 90's band The Breeders.

With the strength so high, it was always going to be a bit of a step into the unknown so I wasn't going to get too precious about hitting numbers spot on. The starting point was simply to make an educated guess about the maximum amount of grain I could fit in my mash tun. I'd used 7 kilos before and there was some room left, so I guesstimated at 8.5 kg being the limit.

I came up with a simple recipe: 8200g of low colour Maris Otter and 300g of Caramalt (that's 3.3%). I added 700g of brewing sugar to the boil, to make 9.2kg of fermentables.

The mash tun looked like this:

Pretty full. It was all dribbling over the edge at the beginning so I'm satisfied I've found the limit. I did the usual big 0 min addition and 60 minute bittering addition to make up the IBUs. The bittering addition was really big: 314g of Cascade, Columbus and Citra, using up a few bag ends along the way. Added to the kettle, it looked like this:

I stirred it in and let it all stand for 20 minutes before turning the cold tap on for the cooling coil. The OG was 1.088 and I used 3 packets of US-05 yeast for the fermentation. That's still probably nowhere near enough but it's what I had and this brew was also an exercise in using up some old ingredients.

Hop schedule

The fermentation went ok, if maybe a bit slow, taking about 10 days to bottom out at 1.008. This was much lower than I'd been expecting, giving 10.5% ABV. In hindsight, I think I got carried away with the dextrose in the boil, resulting in wort which was a bit too racy.

I'd figured that this beer would be made or broken by what happened after fermentation finished, with good dry-hopping technique being really important. I did two separate additions, all T90 pellets, with the first being 100g of Columbus and 100g Citra into the primary FV and the second 100g of Citra and 100g Ahtanum into a secondary vessel after doing a transfer.

I cold-crashed in the second vessel and didn't add finings as I wanted to retain every last bit of flavour. The beer tasted brilliant at this point; like an orgy of hops.

Unfortunately, it went a little wrong from then on. I transferred into an open bucket for bottling, adding enough priming sugar to get 2.4 - 2.5 vols of carbonation. However, the tap got clogged up with hops and after trying in vain to find another way, I ended up having no choice but to blow down the tube to clear the blockage if I was going to get the beer out. The bottling went fine but I tasted a bit of the beer at the end and sadly it was already a bit tired and oxidised; definitely not as good as it had been a day or two before.

Fast forward two weeks and there was no sign of any carbonation. I emailed Dom Driscoll from Thornbridge and he confirmed my fears that 10.5% ABV is just a bit too big an ask for tired US-05 to bottle-condition. He suggested opening the bottles and dropping some fresh champagne yeast in each one.

I'm a bit annoyed with myself for not seeing the problem coming but as they say, you live and learn. I'll do the champagne yeast thing but I'm already itching to just re-do the brew with the schoolboy errors ironed out.

For the record, next time I would:

  • Aim at a little lower ABV, say 9%, for the next one
  • Use less dextrose in the boil
  • Use wet yeast - a big dose of WLP001
  • Do all the dry-hopping in primary
  • Be more careful not to oxidise the beer during transfers
  • Possibly re-seed with fresh yeast before bottling

In hindsight it was probably a bit ambitious to try and make a beer over 10% this early in my home brewing career and I've learnt that it's definitely not the sort of brew you can just do on a whim, with loads of careful planning needed if you want the best results. There is certainly a lot to catch you out when venturing into this territory and the one thing that stands head and shoulders above the rest is the importance of dissolved oxygen control. It's always important to minimise O2 takeup after fermentation is complete but these super-hoppy beers really show you up if you don't.

This is one area where a homebrewer has a serious disadvantage over a professional. It's so much harder to keep oxygen out of a small batch than a big batch because the small batch just has a higher surface area-to-volume ratio. There are steps, such as purging tanks with CO2, that can be taken to help minimise the problem but it'll always be a struggle.

There is one key advantage a homebrewer does have over his or her professional counterpart though: we don't have to make a profit. This beer had a stupid amount of hops in it: 21g/l in dry-hopping and 12g/l in the late kettle addition. Sadly though, if the technique isn't spot on, the amount of hops counts for nowt.