Hop subs

When substituting bittering hops, how important are the hop characteristics? It would seem that the boiling of the hops destroys most everything except the desired bitterness. Also, the hop substitution guide lists Northern Brewer as a substitute for Perle but not the reverse. Can you clarify this for me?
Vern McConnell
Victoria, British Columbia

In my experience, variety does matter whether you are substituting hops in a recipe primarily for bittering or for aroma. The compounds in hops that contribute bitterness to beer are the alpha acids, with humulone, adhumulone and cohumulone being the most significant in terms of amount. Hop chemists use several methods to separate the various compounds in hops and brewing scientists have tried to figure out the effect these compounds have on finished beer flavor. One conclusion scientists made over decades of this type of research is that beers made from hop varieties high in cohumulone have a harsh and unpleasant bitterness. As it turns out, the so-called noble hop varieties are low in cohumulone and this “noble” rank may have been originally assigned to those hop varieties that produce a mellow bitterness.

When you substitute one bittering hop variety for another I think it is important to understand what you are brewing and what that hop variety means to the recipe. If, for example, you are brewing a recipe for a beer that you have never brewed and the recipe calls for a hop variety that is not available at your local shop, substituting just about any variety will not end up in disaster. After all, you have never brewed this beer, have no preconceived expectations and will not know how your change affected the outcome of the brew. If you choose a variety that you like and have used before, then the substitution is not a big deal.

On the other hand, if you have been brewing McConnell’s award-winning Irish Ale for the last 20 years using a specific hop variety, and suddenly that hop variety is not available, things get a bit more complicated. In this case a brewer is certainly not going to grab whatever source of alpha acids is lying about in the hop room. Instead they are more likely to select a replacement variety that has a similar alpha acid profile as the original variety.

I also like a substitute that has a similar alpha acid content because the plant matter in the hop does contribute flavor. Let’s assume a hop variety has been used with a very low alpha acid content and the beer being brewed has a target bitterness level of 25 IBU. If we substitute a variety for the original that has five times more alpha that means that the weight of bittering hops will decrease by a factor of five. If the high hopping rate in the original formulation contributed a grass-like character to the beer then this high-alpha substitute is likely to alter the flavor profile.

Some readers are probably mocking my example . . . “well Mr. Wizhead, this new brew is obviously a marked improvement and the judges at the brew competition are not going to blah, blah, blah” . . . but in the commercial world of brewing consistency is extremely important. So this question has a very different answer depending on the brewer. In the commercial world, when a beer has a glaring defect it is important for it to be consistent because it is part of that beer’s identity. It’s the equivalent of “fixing” the gap in Lauren Hutton’s charming smile.

Aroma variety substitutions become more difficult because humans are more able to detect small variations in aroma than we are at detecting small variations in compounds that we perceive with taste buds and the trigeminal nerve. We are able to differentiate thousands of aromas while only a small handful of tastes. This is why it is difficult to taste food when you have a cold and is also why little kids hold their noses when being forced to eat something new with an objectionable taste. It’s really the sense of small that is being disturbed, not the taste buds or trigeminal nerve.

This is an obtuse way of saying that if you change from one aroma variety to another the differences probably will be detectable, assuming that enough aroma hops are used to make a reasonable contribution to the overall bouquet of the beer and that you have a sniffer that is in good working order. Again, if you are not selling your beer things get easier. I like changing things up because it broadens my personal knowledge of things and if you substitute Perle for Northern Brewer, or vice versa, not only will you have first-hand experience of how this affects aroma, you may also stumble upon something that you really like. You cannot learn this from a table. This is why commercial brewers use pilot breweries to test new ingredients, process changes, etc.

A substitution guide is usually subjective and is based on a combination of conclusions drawn by evaluating data on a hop’s composition and personal experience. I would substitute Perle for Northern Brewer and Northern Brewer for Perle if the hop is used as a bittering hop. In fact, I recently had to find a substitute for Perle used for bittering and Northern Brewer was what we chose. No significant difference in the bitterness character of any of beers was noticed. If the substitution was for an aroma addition I would not have chosen the same variety since Northern Brewer has a coarser aroma to my nose in comparison to Perle. But since the aroma compounds evaporate during boil this difference is not noted in the finished beer.

Brewing is a blend of art and science. While this phrase is uttered by many a brewer, diligently copied down by journalists and has been printed so many times that it has truly become cliché, it is also very appropriate when discussing hop selection.

Steep or mash

Serious brewing references say that grains like oats and flaked barley need to be mashed with base malts rather than just steeped. I have heard that steeping these grains leads to problems with haze, increased possibility of contamination and shorter shelf-life of finished beer. Despite this, I often see these ingredients in extract recipes with instructions to just steep at 160 °F (71 °C). Are the concerns about steeping these grains warranted, and these are just bad recipes? Alternatively, is there a time and place for steeping these grains and what differences can be expected from using them in this way?
Colin Henein
Ottawa, Ontario

I assume when you use the term “serious brewing references” you mean texts that are full of chemistry, biochemistry, microbiology and engineering principles. These serious references are totally devoid of recipes and none on my bookshelves have a picture of anyone actually drinking beer. Pictures of beer torture are the norm. Colloidal stability tests where beer is cycled hot and cold in incubators, foam stability tests where beer is sacrificed to assess its foaming potential and tests where beer is boiled to distill and assay its alcohol content are the photos in the serious texts. These texts are for commercial brewers.

Homebrew texts (presumably not so serious) do have recipes, photos of people drinking beer while brewing (a stunt that would get anyone’s can in serious trouble in the commercial world) and long chapters on the beer style. These books are targeted to homebrewers who are trying to brew the best beer they can using the sometimes limited tools and time that they are willing to buy, build and devote to their hobby.

I am a product of formal brewing education and like the science contained in these serious texts. When I put on my mortarboard I say that the only grains that belong in a steeping bag are crystal/caramel malts, roasted barley and roasted malts. Anything else must be mashed. This rule makes extract brewing fairly limited and would seem to suggest that all-grain is the way to go. While I am a big advocate of all-grain brewing, because it is the path to brewing freedom and also is not nearly as difficult as all-grain brewers claim when their chests are all puffed and inflated while critiquing the efforts of extract brewers, this method does add more time to the brew day. And if you are fastidious about your kitchen and don’t have a place that is as easily cleaned up with a hose as it is soiled by digging out a lauter tun, extract brewing has its benefits.

Extract brewers, in their pursuit of creativity, have tossed out much of the basics about mashing found in serious brewing texts. I typically turned a blind eye to many of the methods described in extract recipes because my brewing experience is different. The way I see it is that enough brewers are using materials in ways that fly in the face of commercial convention that their efforts are surely not the brewing equivalent of pounding sand.

But what does really happen when raw cereal grains and malted grains are steeped in a dilute solution at or above 160 °F (71 °C)? The starches and simple sugars contained in these grains will dissolve in the steeping liquor and any enzymes present will also be released into solution. The concentration of starches and enzymes in a brewery mash is considerably higher and, in accordance with Michaelis-Menten enzyme kinetics, the rate that these starches are converted to fermentable sugars is also considerably higher compared to what is seen in an extract brewer’s steep pot. Additionally, any enzymes present, for example if Munich malt is steeped, in this solution begin to denature because of the high temperature. In a nutshell, this means that not much starch degradation occurs.

Since brewing yeast does not secrete enzymes that degrade starch and do not ferment starch, any starch in wort will be found in the finished beer. And as you state, starch in beer can cause haze issues and can also cause problems with microbiological stability. Certain yeasts, such as Brettanomyces, and bacteria, such as Pediococcus, can cause super-attenuation. This means that these organisms can ferment compounds that brewing yeast do not. If starch remains in beer it is an invitation to these possible contaminants to grow and spread their funk into your beer. Usually this is unwanted, but if you wanted to brew something funky then these bugs may be just what are needed. As it happens lambics have starch in their worts before fermentation and the distinctive character in these beers arising during the long aging (after a somewhat normal yeast fermentation) requires residual carbohydrates for these bugs to chew on.

When I make suggestions about brewing I do stick to my formal training and I do not personally recommend steeping grains other than crystal/caramel and roasted types. Any other material used in the brewhouse needs to be enzymatically acted upon in a brewers mash.

With that being said, other brewers have different opinions and offer different advice. While it seems from the number of recipes suggesting unconventional advice that such advice may indeed work for those offering it, I do recommend taking this advice with some skepticism and caution. If one of the primary goals of homebrewing is to brew good beer a logical brewer will recognize that the practices used by commercial brewers share this goal. If a technique is not commonly used by commercial brewers there is probably a reason. Of course commercial brewers, with very few exceptions, employ a mashing method and techniques surrounding steeping that are totally irrelevant.

So if you are an extract brewer, I would heed the warnings of the texts while also listening to practical advice offered by fellow homebrewers who have developed good beers with unconventional methods.

Brew Your Own Technical Editor Ashton Lewis has been answering homebrew questions as his alter ego Mr. Wizard for the last 12 years. A selection of his Wizard columns have been collected in “The Homebrewer’s Answer Book,” available online at brewyourownstore.com.

Do you have a homebrewing question for Ashton? Send inquiries to Brew Your Own, 5515 Main Street, Manchester Center, VT 05255 or send your e-mail to wiz@byo.com. If you submit your question by e-mail, please include your full name and hometown. In every issue, the Wizard will select a few questions for publication. Unfortunately, he can’t respond personally. Sorry!