Inspired by the great New England IPAs, after aroma, mouthfeel is probably the second thing I look for in a great hop forward beer. Malt profiles are important, but subtle tweaks are hardly noticeable in a heavily hopped beer and for the most part I don’t care for a lot of malt character anyways (my preference of course). IBU levels are also important, but I have a hard time detecting a difference in slight IBU changes from one beer to another or even whirlpool addition changes. Changes in mouthfeel on the other hand can be very easy to detect, but not always easy to achieve.

A hoppy beer with an extremely soft and silky-like mouthfeel is one of the main characteristic traits distinguishing a New England IPAs from a traditional IPA. To my palate, this softness quality seems to aide in rounding out a beers bitterness to flavor levels helping to make the overall experience a little more in balance and elegant. I hear a lot about beers being in balance in terms of malt to hops, but I really have no idea what this means. What does resonate with me though is this idea of bitterness being balanced with hop flavor and I’m inclined to think that mouthfeel softness helps meld this ratio.

I haven’t always been after a soft mouthfeel in IPAs; I’ve evolved (to steal a politician’s word). just a few years ago I was brewing heavy sulfate IPAs and trying to get them as dry as possible, mostly because this is what I was reading on blogs and listening to on podcasts on the best methods. Don’t get me wrong, I enjoyed these beers, but as I got the chance to try some of the great New England IPAs I was immediately questioning my current methods. The incredible soft mouthfeel these beers had really seemed to bring the flavors to the forefront and the bitterness seemed to only aide in the impression of a hop saturated flavors. I, like many others, were obsessed with this quality in the New England hoppy beers and started chasing a softer mouthfeel, and this post documents my experience and research on the topic.

Changes in Brewing Process | Relation to Mouthfeel Softness

I almost completely focus my brewing on hoppy mid-low ABV flavorful beers. Of course I still brew and really enjoy aged sours and tart saisons, but the majority of these beers get solid dry-hop treatment as well! This focus on basically one style has really been valuable (I think) in being able to constantly tweak these beers in various ways in an attempt to improve them. Every beer I brew I record my scores from 0-5 in a number of categories as a way of scoring all the various aspects of the beer. I rank everything from bitterness levels, hop aroma detectability, minerality, stability, clarity, hop oil information, aroma characteristics, head retention, excitement level, etc.

I mention this overly obsessive rating system because in a previous post, I looked at 25 batches of beer all fermented with WLP002 and examined what factors had the biggest influence on final gravities with the English yeast strain. For this post focused on mouthfeel, I decided to look at the same 25 batches, all with WLP002, and examine what factors had the biggest impact on my mouthfeel softness scores. I also looked at a few studies on the subject in an attempt to put a little academic data behind my results to see if they stack up or not.

One main reason I chose to focus on this set of 25 batches is because recent experience (as well as the experience of others) has shown me that yeast choice alone can greatly influence mouthfeel. So focusing on beers all fermented with the same yeast strain avoids the yeast factor altogether. Keep in mind that many of these beers were created and tested before and after I started attempting to achieve a softer mouthfeel in hoppy beers, so although you’re always tempted to rate things higher when you’re trying to achieve a certain goal, many data points were entered without this stated goal even in mind or prior to me even tasting a New England IPA.

Below are the results from correlating the data from the 25 batches to different brewing process changes to the mouthfeel score I gave each beer. Below the chart is a more in-depth look at each process change and possible explanations for the results.

Calcium Chloride

As you can see from my experience, calcium chloride alone had the biggest impact on increasing my mouthfeel softness score. As the grams/gallon of calcium chloride (CaCl2) increased, so did my softness rating. The same is true with the gypsum/calcium chloride ratio (S04/CaCl2), as the ratio of gypsum to calcium chloride decreased (negative relationship) so did my mouthfeel softness score.

Although slightly dated, an interesting review published in 1992 titled, “The Mouthfeel of Beer – A Review,” which looked at various factors influencing the mouthfeel included a discussion on calcium chloride. Right away the review says “Although no sensory evidence exists, it is generally assumed that chloride ions yield beers which are “rounder” more full and mellower and softer in the palate.” Although no hard evidence was presented for this claim, even in 1992 there seemed to be an agreement that calcium chloride aided mouthfeel. The review goes on to use the work of another study in an old Journal of the Institute of Brewing that described the taste of chloride ion as “sweet” and full.” An early 90’s Journal of the American Society of Brewing Chemists found a positive correlation with the chloride concentration of 30 commercial beers when describing the beer’s fullness. Lastly, a 1981 paper found that beers produced with CaCl2 were preferred to beers produced with calcium sulfate.

With no data explaining why, a 1967 paper presented the “proper” sulfate:chloride ratios in different styles of beer suggesting the following:

Beer Type Sulfate:Chloride Ratio Dry, Bitter, Pale Ale 2:1 Full, Sweeter, Mild Ale 2:3 Softer, Stout requires little sulfate

I’m not sure if I completely agree with the ratios, but it was interesting to me that for softer styles of beer (like a stout) “very little sulfate” is required. Looking at this recommendation in the current lens of New England IPAs, I couldn’t help to think that maybe I should be approaching this style as if it was closer to a traditional softer stout style of beer to achieve a softer palate for the hops. When I first started brewing hoppy beers I read that my water profile should be similar to the Burton-On-Trent water profile in order to accentuate the hops. This water profile is absolutely S04 crazy with a ratio of 51:1. While I haven’t brewed with water this extreme, I have gone as high as 6:1. Although this particular beer wasn’t terrible by any means, I did end up rating it below average in mouthfeel softness and sweetness (more on sweetness below). I also noted that the water additions in this particular beer were “a little too heavy, I get salty/mineral aftertaste that doesn’t seem appropriate.”

In the 25 batches looked at above, the S04/CaCI2 ratio ranged anywhere from 4.7:1 to 0.45:1. As the scatter chart of these beers below shows, I had the most successes in terms of softness when the ratio was around 1.5:1, which is close to an even split of gypsum/calcium chloride. I’ve recently tried a batch with 100% calcium chloride, which wasn’t the slam dunk as I thought it might be, I definitely considered the mouthfeel soft, but it wasn’t enough to convince me there isn’t a role for sulfates in hoppy beers still, what that role is I’m not sure yet.

An article in the Journal of Automated Methods & Management in Chemistry furthered the notion of using less sulfates in hopped beers. The article states that “an excess of sulfate gives a sharp, dry edge to well-hopped beers and the level present should be minimized as much as possible.” Unless your goal is dryer sharper IPAs, this seems like further proof to lower the levels of gypsum in hoppy beers. My personal experience with heavy sulfate hoppy beers are that the hop flavor is reduced and the bitterness perception increases becoming harsher as the level increases.

I think it’s fair to say that most brewers will add all of their mineral additions to the mash, possibly splitting the additions in two, treating the strike and sparge water separately. What if we approach it in the same way but withhold a portion of the calcium chloride addition and add it directly to the boil? With no grains from the mash acting as a filter of sorts removing some of the chloride, it seems possible this direct addition to the boil could enhance the softness effect. I’ve experimented with adding the calcium chloride addition calculated for the sparge water only directly to the boil, but have backed that number down a little. It may be I’m sensitive to minerality in beers, but now I’m targeting around 4 grams of calcium chloride or less directly into the boil for a 5 gallon. So I’m withholding about 3.5-4 grams of the chloride addition from the sparge to add to the boil for a 5 gallon batch with reverse osmosis water. My last attempt at this was for a S04/CaCI2 ratio of 0.8:1 (111.6 ppm Sulfate and 131.5 ppm Chloride). [UPDATE: I’ve tried adding the sparge water minerals directly to the boil a number of times and wasn’t thrilled with the results. I felt like I was getting more a mineral taste to the beer which seemed to be enhancing the dryness a touch more than I wanted. I now treat just the mash and sparge water and don’t add anything directly to the boil].

As far as the optimal level (ppm) of chloride to have in a beer, I’m not sure. A 1971 journal recommended a level of ~200 mg/L of CaCl2 to produce a lager with a proper mouthfeel. . This recommendation seems a little high based on my own experience and it’s for a lager (and dated). The highest I went in the 25 batches examined above was 182.5 ppm. I have a good friend and great brewer who has gone as high as 250 ppm of chloride without success describing the beer as medicinal and astringent. It might also depend on how much gypsum you’re adding to the beer as well.

Lastly on calcium chloride, to experiment with chloride you can always try adding a little to your beer after fermentation (directly to a pint) to see if you like what the elevated levels does for the beer. You can also try adding it to other liquids like coffee to test its softness ability. I gave it a shot in a CHEMEX with reverse osmosis water, I added less than a gram of calcium chloride to 600 grams of reverse osmosis water and 40 grams freshly coarse ground coffee. Sure enough, it was a little softer and fuller (although I was probably looking for this, I should have added it directly to cup and done a side-by-side). I might just start adding some chloride to coffee all the time now (I brew coffee with R/O water as well).

There has also been a look at the sulfate levels of hop forward beers and it’s effect on hop flavor. A “clear negative correlation” with sulfate levels and perceived hop flavors was found. This suggests that not only does increased sulfate levels detract from the softness of the mouthfeel, it also can lower the hop flavor of a beer!