We thoroughly enjoyed our first collaboration with Siren back in September, and once we came up with the Tropical Death Party idea (possibly the first time we've named a beer before deciding what it was even going to be) we instantly decided we should invite them back to help us step up the recipe. Wishing to push ourselves and our equipment to the maximum, we've turned the ABV up to 10, filling the mash tun twice to the brim to squeeze out every molecule of fermentable sugar we could. The bulk of the grist for the beer was classic IPA – Our usual pale malt, Flagon, along Vienna and a good portion of Oats and a sprinkling of crystal malt. For mouthfeel and sweetness, and that hint of chocolate Bounty bar, we threw in an addition of Lactose sugar. Then, as we both agree on one think with the Black IPA style, we wanted all the colour with as little roast as possible. Cue a new technique for both of us, cold-steeping all the colour separately.
When brewing Stouts and Porters it is standard practise to add all of the dark grains into the mash as normal. As a result of the kilning process that these roasted malts go through, their proteins and starches have been largely broken down and contribute minimal fermentable sugars to the wort. You are effectively just steeping them for colour. However prolonged contact with hot water can often lead to these dark grains contributing harsh, astringent flavours to the beer as complex melanoiden and tannins from the grain husk are extracted. Using specialist de-husked grains (such as Carafa Spezial III from Weyermann's of Germany) counters much of this but can still contribute some of the classic stout flavours we want to avoid in a Black IPA. Previously, in beers such as Attack on the Bounty, we'd added a layer of dark grains to the top of the mash bed before sparging through them to extract the colour, but we were keen to explore further ways to find the colour and subtlety we were after.
By cold steeping a portion of the dark grains (we added a small percentage of Carafa Spezial III to the mash, enough for a mid-brown hue as a starting point) we were able to extract all the colour we needed, as well as some lovely dark chocolate aromas. This liquid was added late in the boil, again so as to avoid harsh flavour contributions from heat contact.
From here on in it was all about big hop and pina colada flavours. As with 'Bounty', there's only one hop variety to complement the rich toasted coconut – Sorachi Ace. Developed in Japan in the 80s, it contributes a unique flavour profile of lemongrass, dill, citrus and, as mentioned, coconut. We paired it with a supporting cast of Vics Secret, a rising star from Australia which gives off pungent Passion Fruit and Pineapple, along with house favourites Mosaic and Citra. We went for a restrained flame out kettle addition before goingto town with the dry-hop late in fermentation. Alongside 25kg of hops went a plantation's worth of puréed Pineapple and then finally we sent the beer to spend a week sat on 10kg of Toasted Coconut in the conditioning tank.
Thick in body but super silky in the mouth. There's milk chocolate and coconut upfront before an almighty tropical punch takes over.