Cloudwater brew company

24.12.15

DIPA v1.0

If you managed to read my previous post on our hoppy beer you’ll recall that I think we’re off to a good start as a brewery, but that we’ve been feeling like something is missing from our range of hop focused beers.  We’re not going to push all our hoppy beers to the limits, as we prefer balance and drinkability too much to do anything like that, but what we’ve set out to do is make a beer or two a year (or more if there’s demand when ingredients are available) that’s very, very hoppy indeed.

Below you’ll find the recipe and process we used to produce our first Double IPA in as much detail as we can muster, a little over a month after the brew day (at the time of writing).  I hope it’s interesting and useful to anyone wanting to compare how we did what we did with what they do.  We’re only just setting out on our quest to make the sort of hoppy beer that is deeply impressive to us, so please forgive any glaring errors.  If you’d like to offer us feedback please do so by emailing info@cloudwaterbrew.co.

Further below are thoughts by Mark Tranter (of Burning Sky), Logan Plant and (of Beavertown Brewery), Alex Troncoso (of Lost and Grounded Brewers, launching in 2016), and James Watt (of Brewdog).

DRY INGREDIENTS

Grist:
Extra Pale Maris Otter 1480kg 96.73%
Liquid Glucose Syrup 50kg 3.27%
CaCl2 800g
CaSO4 1200g
Lactic Acid 300ml

Kettle additions:

Bittering
Pilgrim CO2 Extract 645g

Flame Out
Simcoe T90 13200g
Centennial T90 8000g
Yeast vitamin 170g
Koppaclear 28 tablets x 5g per brew

Hop back hops:
Ella 6200g
Pacific Jade 3450g

Yeast:
American Pale Ale Yeast

Dry hops:
Vic's Secret T90 7200g 20%
Nelson Sauvin T90 7200g 20%
Centennial T90 7200g 20%
Chinook T90 7200g 20%
Citra T90 7200g 20% 

TARGETS

ABV 9.00%
Mash Temp 64ºC
Initial EBU 15
Hot side Beer IBU 31 (Low cohumulone hops chosen for a smoother finish)
Liquor:Grist 2.8
Target Mash pH 5.3
Mash Out Temp 78ºC
Gravity Starting 1.080º, finishing 1.010º-1.006º

WORT PRODUCTION

Explaining the Grist recipe and Kettle additions:

Extra Pale Maris Otter has a great flavour, is low colour, and offers a fairly clean malt contribution (that doesn't get in the way of the hops).  We think the best beers we’ve made have had it as a base malt, so choosing to make it the near complete base of our DIPA was an easy decision to make.

The target for the brew was to get down to at least 1.010º (it actually finished a little lower than we calculated, at 1.006º), as the US IPAs and DIPAs we tried and tested back in September were all around that gravity in package.  The final runnings were 1066.4º, and conversion took 2 hours (as we included a 50ºC stand which we’d scrap next time).  The starting gravity was 1.072º.  To some extent we’re happy with the resulting dryness, but next time more body would contribute more mouthfeel, and a little less dryness could accentuate fruity, juicy notes from the hops.

We used glucose to achieve a lighter, drier, high ABV beer, and although the glucose we used is 94% fermentable, we’d likely switch out to dextrose next time, which has 100% fermentability.  In addition to the change to dextrose, we would also raise the mash temperature a little to leave more complex sugars so the terminal gravity would be more in specification.

As standard in all brews we added yeast vitamins to assist yeast growth and function. Highly nutritious (some may say adequately nutritious) wort during the lag phase ensures a pH drop of 4.9 to 4.4 in 24 hours, which is important because it indicates good yeast growth and protects from coliform bacteria.

Also customary in our brewing process we added Koppaclear, which aids trub formation during cold break.

Please see below mash, lauter, and kettle charts indicating temperature steps, tank actions, and additions (K1: Copper Up, CO2 extract / K2: Boil end / K3: Whirlpool / K4: Flame out hops / K5: Whirlpool / Transfer to heat exchange):


What we’ll do the same and differently next time:

While we ended up with a DIPA that is juicy, fruity, light (quite low fusel alcohols), and incredibly drinkable, I think we’re in agreement that a little more of a rounded and flavourful malt base could be wonderful, but a near carbon copy of this malt bill is likely to let the hops shine through again.  We’ve since discovered that our mill is letting us down, leaving us fighting poorer extracts than we’d like, so we’ve switched out to crushed malt for the time being, gaining better extracts and smoother brew days.  It’s likely that we’ll still be using crushed malt when we brew such a boldly hoppy beer again.

Using CO2 extract for bitterness gave us great control, and complete confidence that we wouldn’t end up overpowering aroma with bitterness (as we have done many times before).  We’ll definitely use CO2 extract again for bitterness and are considering switching over to it for all hoppy beer until we dial back bitterness to a more balanced level (similar to what we achieved with this DIPA).  Of course we have an option to use pre-isomerised extract next time, which would allow us to dial back the initial bitterness even more, and adjust bitterness later in the process.

FERMENTATION AND COLD SIDE ADDITIONS

Explaining of our choice of aroma hops:

When we discussed making a DIPA we set out to make the best hoppy beer we’ve made so far.  I think we’ve achieved this, but there’s more we can do next time!  With Antipodean hops in peak season they made up the bulk of our aroma additions, but we backed them up with some rather more modern classic US hops, even if they were getting on a bit.  In hindsight, whilst this gave us a great rounded flavour that was very juicy, we all missed the raspiness that we like just a touch of in big hoppy beers.  

It’s likely that the next DIPA from us would feature fewer varieties of hops, and may exclusively feature US hops too (depending on when we make another batch).  A bit of (as fresh as we can get) mosaic or simcoe would go a long way towards a more modern classic West Coast flavour, but as befits our philosophy, we’ll work with the best ingredients available to us at the time.

A probable combination of sulfide (DMDS, DMTS, and 3,3-dimethylallyl methyl sulphide) notes were prominent in the Nelson Sauvin we added, so we scrubbed these out by bubbling CO2 through the FV every day for 5 days.  We intended to use CO2 to re-suspend the hops daily anyhow.  During hopping and conditioning in the FV we put a spunding valve on the tank so that we could hold a top pressure of 0.5 bar on the beer whilst releasing excess to atmosphere.  These scrubbing and venting processes resulted in an effective drop off of sulfides (ranging from black onion seed, cumin, to onion aromas and flavours), but may have scrubbed other positive aromas too.  

After we were satisfied that the sulfide notes were sufficiently tamed, we added our ageing 2014 season US dry hop charge.  Even though we never store hops above 3ºC it’s obvious to us that they lose their edge over time.  We can’t wait to go back to this beer with fresh US hops.

What we’ll do the same and differently next time with aroma hops:

Even though this year's Nelson Sauvin ends up rounding out to a lovely rich late harvest grape flavour, and wouldn’t usually present with the sulfide notes we found (said to be attributed to late harvesting, and common in US hops such as Summit, Mosaic, and 2014 Citra), to use a hop that required venting off might be a little too risky next time.  We’d rather not scrub anything out of the beer, nor have to wait for flavours to round out at the expense of other flavours diminishing or losing their snap.  We might decide to skip Nelson Sauvin, or treat it differently next time.  Rudimentary ideas we have currently are to make a hop tea to flash off some unwanted compounds with hot water from HLT, or ferment a small batch of wort in an open top fermenter to allow the compounds to be released more gently.  Both rudimentary ideas would need testing first, but may help us in the future to use hops that aren’t yet rounded enough.

Another idea we’re keen on investigating, is whether a drop or two of hop extract would work very late on to add a top note to the beer if an addition was made in our brite beer tank, just before packaging, for example.  

Explanation of the cold side program, FV additions, and dry hopping procedure:

The wort was oxygenated to 10-12ppm and cooled to 14.5ºC through our heat exchanger as it was transferred across to FV.  Fermentation was capped at 16ºC for the first 3 days, then the cap raised to 21ºC as fermentation slowed, although it never got above 19.5ºC.

As usual we filled our double brew length 48HL FV over two brews with 36HL of wort, pitching (1.2M/ml/ºPlato) 20M/ml of yeast from yeast tubs. We also pitched 250ml of Brewer’s Clarex, an enzyme used to deconstruct protein, reducing the chances of colloidal instability post packaging.  We started using Brewer’s Clarex (used to make gluten free beer, and now studied extensively to discover whether it can be used to make other food and drinks gluten free too) after we found some of our summer Lager, APA, and IPA bottles displayed protein flocculants (glyco-proteins) some weeks after packaging.  We’re now pretty sure that allowing too much foam to develop in BBT during carbonation prior to packaging is most likely to have caused said foam to reach the top of the tank, collapse, and then eventually flocculate in bottle.  Protein flocculants are a common sight in some beers, but we aren’t keen in case they worry any consumers who may misidentify them as yeast clumps instead.

Please see below for our fermentation chart, indicating when we added dry hops, and the temperature cap we placed on fermentation with our glycol cooling system.



Satisfied that fermentation was coming to an end we conducted a VDK test, which we performed by taking two samples, setting one side at room temperature, and heating the other to 60ºC for an hour.  If we detect diacetyl or even a dramatic change (except staling), we leave the beer at fermentation temperature for 24 hours and then test it again, passing it only when we’re satisfied there’s no diacetyl.  We got stung a few times early on with diacetyl, and find it just about intolerable in any beer, so we’re trying our best to pay close attention to save ourselves pain after packaging!  We conditioned at 12ºC for 10 days then at -1ºC for another 10 days, dropping slurry everyday.  The finings agent we use is pretty timid, so we felt happy with an addition of 23 kg (115% of what we’d customarily use in similar beers).

When conditioning and final solid matter drops were complete, we transferred the beer under CO2 pressure (avoiding the use of a pump to reduce shear forces on the beer) into a CO2 purged BBT, and held a top pressure of 0.5 bar whilst we gassed the beer up to 2.6 volumes of CO2 as gently as we could.

We ended up with a cell count of 0.2M/ml in package, well within the targets we aspire to.  To ensure as much protection of all the flavour in the beer we double evac purged the bottles with CO2 during bottling, and stored the package beer at 6ºC in our cold store straight after packaging, never allowing it to warm up.

What we’ll do the same and differently next time:

We’re going to run some tests on more gentle cold conditioning, and also whether we can skip using finings at all, if we feel that we can package with an acceptable yeast count, and a fuller flavour drink too.  

A batch of IPA we have in FV right now has had a corny keg pulled off before dry hopping, and will have another corny keg pulled off after VDK pass (Vicinal Diketone).  Another corny will be taken off after cold conditioning for 4 days at 7ºC, and again after cold conditioning for 3 days at -1ºC, leaving us with five samples to test side by side in a few weeks time (we’ll probably put them on at our tap if anyone is interested in trying them out to see what effect each stage of the process has).

I hope you’ve found the above interesting, and if you brew at all, even useful.  Brewer or not, we’d love to hear any questions or comments you have about this beer, and the recipe and processes we used to produce it.  Below, you’ll find feedback from the brewers listed at the top of this post.

A few words from Mark Tranter, of Burning Sky Brewery (I sent Mark some DIPA to try in case he wanted to offer any feedback on it):

“I really enjoyed the DIPA, though it is a style that I rarely drink these days. I often find that they are too heavy for me, in terms of cloying malt and all too often taste like a hoppy barley wine - choosing a low finishing gravity (by accident, or otherwise), made it more approachable/ dangerous. The simple malt grist keeps it easy on the palate - at that strength, there is always enough body, without detracting from the hops by over use of crystal malts etc.
Personally, I would have kept the aroma hops a lot more streamlined - in terms of volume of varieties. You got loads of juicy fruit aromas, which people heart at the moment, but were they all contributing much? I think choosing a few (2-4 varieties), and letting them shine would push the flavours further. But that's just one reporter's opinion...
We trialled hop extract for bitterness but found it overtly expensive. In the end we have been reducing our bittering hops (magnum), to a minimum to allow the aroma hops to shine and always go with a first wort addition, no start of boil to keep perceived bitterness lower and more gentle.
We favour multiple late kettle additions, to give a layering of flavours, the last (big), addition goes in after liquoring back to preserve as much of the oils as possible.
We messed around with loads of dry hopping techniques, from slurries to multi stage but in the end found that one addition with a shorter contact time than most people would use, suits our beers. Similarly we have fiddled with temperatures for the dry hop period. I guess what I'm saying is, there is no right or wrong way, what works for some doesn't work for others - experiment, learn from your practices and experiences and find what suits your beers and ultimately your palate.
If there is one thing we have become super vigilant on, then it's potential oxygen pick up post fermentation, so keeping on top of that is always paramount - be it in cellaring/ packaging, or wherever.
Sometimes with running a brewery, you get set in your ways of doing things, then suddenly have some time out, a day 'off', or what not and you get a bit of a 'well what if we did this...' moment. Articles such as the one you are publishing will no doubt help many with that, so thank you.”

And a few words from Logan Plant of Beavertown Brewery (I sent Logan some DIPA to try, in case he fancied giving us any feedback on it).

“Thank you so much for the DIPA. It was a really nice surprise and kicked ass at the end of the day. I sat down with Jenn and a few of the guys and we really enjoyed it! At present I have a few Pliny’s in the fridge at home (not sharing ;-)) and it had the same drinkability which I find essential when brewing DIPA’s. The aromas were cutting and punchy and the finish dry, leaving me wanting more, always a good sign for a 9% beer!
We are actually working on a straight IPA recipe at present, we don’t have one in our core range! The thing I love in IPA’s is of course hops. We like to keep the grist simple and clean providing a platform the hops to let rip. Your DIPA had exactly that. Yeast is a big factor too. We generally use a neutral, clean strain. This in my opinion this lets everything sit nicely together. The yeast lets the malt create the backbone and allows the hops to sing. Almost like a three note chord! Temperature during fermentation is also key. We run into the FV at around 18c and keep it cool through until the last phase of fermentation where we let it free rise to around 21-22c. A quick, clean fermentation is key. Dryness to me is also essential, I don’t like IPAs to be too cloying or sweet, so less crystal malt the better and also attenuating the mass of the sugars right down low. We use dextrose sugars to help the attenuation along. Then the hops. We go late in the brew on mass. I love to blend and layer flavours/textures from the hops in the boil. We also look to dry hop on the warm side and go double/triple particularly on our DIPA Skull King and TIPA Power of the Voodoo. Then maturation is key. There is so much going on, we monitor the finished brew until all flavours/aromas are bang on and settled then package and release asap for fresh consumption."

Alex Troncoso (who also had a sample bottle from me too, and is soon to open what will surely be one of the most exciting breweries of 2016, Lost and Grounded) writes: 

"Thanks for the beer, it was amazing! My overall impression of the beer were clear from the first smell and taste - a fantastic DIPA. I am not a fan of overtly crystal malt-led (D)IPAs and I think keeping the grist simple was the key for me.
Specific comments on the recipe and process:
- Nice mix of chloride and sulphate. I think if the salts were only sulphate then the bitterness would have been too harsh; the chloride really rounds it out.
- I was very surprised by the degree of attenuation achieved; I thought much more adjunct would be required. Another trick is to go for a much thicker mash (eg. 2.4L/kg) to better protect the enzymes and achieve a higher attenuation... But you obviously didn't have that problem anyhow!
- I would stick with the more intensive mashing regime (protein rest, etc) as the more intensive the mash, the higher the extract. Also, the protein rest would have possibly increased the FAN which made the yeast happier, but that is a text book assumption!
- Interesting choice of bittering with the CO2 extract. Science is there to be used, and I liked to see you using a lesser used product (in 'craft' circles that is) to dial in the bitterness.
- The list of hops used was quite extensive and personally I would cull it back to get a little more focus on a certain character. But in saying that the beer was bloody good, so don't listen to me too much! The maturation and scrubbing regime was interesting - perhaps you could have used less hops and achieved the same result without any scrubbing?"

Lastly, James Watt of Brewdog shared the recipe with me for Born To Die (the 2nd batch) which is as follows:

Grist for 100hl: Type / kg / %
Pale Ale Malt 2200kg  84.6%
Maris Otter Extra Pale  400kg  15.4%

Hops: Type / kg / α-acid [%]
CO2 Extract 10.00kg  50.00%
Amarillo 5.00kg 9.00%
Simcoe 5.00kg  12.50%
Mosaic 10.00kg  12.00%
Citra 10.00kg  12.00%
Amarillo 10.00kg  9.00%
Simcoe 10.00kg  12.50%

Dryhops for 100hl (1.0kg/hl)
25kg Citra
25kg Amarillo
25kg Simcoe
25kg Mosaic

Thanks to Mark, Logan, and Alex for sharing their thoughts, techniques and to James for sharing the Born to Die recipe.  Not only are we shooting for ever better hoppy beer, more openness and clarity with our beer making, but ever more dialogue and openness from the rest of the industry too.  

With thanks to you all for your kind words and high praise of our first DIPA, here's to 2016, and the strides we'll all make to present to you the best hoppy beer we can possibly make.

Share
close