Friday 24 May 2024

High Bitterness & Low Hop Flavour in West Coast IPA

This article is going to be a bit of a brain dump, and perhaps a way to research and compile our own thoughts and evidence around this. As per the title, our latest challenge in our homebrewing journey has been a lack of hop flavour, but high bitterness in our West Coast IPA's.

As an amateur homebrewer, we've had a decent amount of success at (in our opinion) making all sorts of different beer styles, from lagers, to amber ales and pacific ales. But one style that we're struggling to get right is the West Coast IPA. After two separate attempts, using different recipes, we've somehow ended up with two beers that taste eerily similar - and not right.

We were far from happy with our first attempt - the resulting beer had a good amount of bitterness, but really lacked the hop punch that is trademark to the style. Along with the bitterness, there was a residual sweetness that's a little bit difficult to describe. Perhaps a bit of candied orange and a bit caramelly, but definitely not diacetyl. We're confident of this as we actually sent this one off to a competition which confirmed our impression of being too sweet, but also not having any diacetyl. What it definitely didn't have was the citrus, floral, and piney flavours that you would expect given the fairly heavy hopping schedule in the beer. 

After this first attempt, we attributed the sweetness to a grain bill that was too heavy on the specialty malts, so we recently had our second attempt at a West Coast IPA with the Awesome Foursome recipe, using 100g of 4 different hop varieties (with the exception of Centennial which was featured in both WCIPA's), and a very different grain bill. Yet somehow, as previously mentioned, we've been left with a finished beer that tastes very similar to the first one, but with a totally different recipe.

We're confident in our brewing process, from hot side to cold side. For both batches we pitched plenty of dry yeast, and had healthy fermentations that were temperature controlled and had finishing gravities around where they were expected (a high FG could of course leave some residual sweetness). So what gives?

We're ruling out a grain bill problem - both recipes had around 6.5kg of grain to give a starting gravity (OG) in the ballpark of what is required (around 1.065) - and there are plenty of IPA recipes using similar amounts. We dialled back the specialty malts on our second attempt, so we just don't think it's possible that this is the issue.

Our hop schedule seemed to be where it needed to be, with a decent beginning of boil addition followed by some late (5 minute) additions and a hefty whirlpool, along with a decent dry hop charge in both recipes.

We also thought that perhaps there was something going on with the Centennial hops - as this was one of the few common factors in our WCIPA's, however the flavour profile just doesn't match up to what you'd expect from Centennial. Given it's relatively low alpha acid content compared to the other hops that have been used, it shouldn't have dominated in terms of flavour, and it ultimately only contributed to 1/3 or 1/4 of the hops being used in each batch.

What we're leaning towards now is the water profile that we used in both of these beers - namely, the Brewfather "Hoppy" water profile. Based off our source water profiles, using this target water profile gave us around 100ppm of calcium, around 50-60ppm of chloride, and ~270ppm of sulfate. There are two things to consider here, which is the total amount of sulfate used, as well as the ratio of sulfate to chloride.

Our understanding of sulfates was that they would help to accentuate not only bitterness, but also the overall hop flavour in the finished beer, so elevated levels would help them shine brighter, right? When brewing hazy beers like a hazy pale ale or a hazy IPA, the inverse ratio (chloride to sulfate) is often used with a heavy amount of chloride and low amount of sulfate being recommended to give a fluffy mouthfeel, yet against conventional wisdom, also help to accentuate hop aroma and flavour, with a recommended ratio of at least 2:1, or even as high as 4 or 5:1 - there are some caveats to this but we're not going to get into that now.

So is our water profile to blame for our unexpected WCIPA flavour profile? Perhaps such a high sulfate to chloride ratio is enhancing the bitterness to a point that is totally overriding the other desirable hop flavours? Or perhaps the actual level of sulfate is too high?

Scott Janish, author of The New IPA has an award winning West Coast IPA recipe which uses 242.7ppm of sulfate and 52.5ppm of chloride, and 99ppm of calcium. Not miles apart from where our water profile is, but we've also read that 250ppm of sulfate is perhaps the upper limit, a number which we exceeded in both our WCIPA's.

BeerSmith also have a great blog post on the Sulfate to Chloride ratio, which quotes some information published by John Palmer with some guidelines on the ratio which we'll include below;

0-0.4: Too Malty
0.6-0.6: Very Malty
0.6-0.8: Malty
0.8-1.5: Balanced
1.5-2.0:Slightly Bitter
2-4: Bitter
4-9: Very Bitter
9+: Too Bitter

Based off this, our WCIPA sulfate to chloride ratios were in the lower part of the Very Bitter range, but this article also mentions both sulfate and chloride are typically within the 50-250ppm range (key here being the upper limit of 250ppm).

Looking back through our previous recipes, we've had a number of pale ales that also used the Brewfather hoppy water profile, and reflecting on these they also had somewhat of a diminished hop character and accentuated bitterness, so we're definitely going to be trying some different water profiles for these moving forward. 

For future reference, Black Hops, an award winning Australian craft brewery recommend 150ppm of sulfate and 50ppm of chloride (for a 3:1 sulfate to chloride ratio) for their pale ales as per their Water Chemistry blog post.

We'll definitely be trialling some different sulfate and chloride levels in our future IPA's, as well as our Pale Ale's to see how it changes the perceived hop flavours.

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