T90 VS. T45 Hop Pellets, Light Struck Beer: Mr. Wizard
Q
The effect of light on wort and beer I recently noticed that hop pellets are described as either T90 or T45. What do these values mean? What are the pros and cons of each? Is it possible to tell which you’re purchasing from homebrewing stores (I have not seen the values used in hop descriptions)?
Sam Schalley
Rochester, Minnesota
A
The “T” in T90 and T45 pellets is an abbreviation for “Type,” and the general designation relates the weight of the pellet to the whole hops coming into the process. One pound of whole cone hops yields about 0.9 pound (0.4 kg) of pellets in the case of T90 pellets, and 0.45 pound (0.2 kg) of pellets in the case of T45 pellets. At first glance it seems that the process used to make T45 pellets is only half as efficient as the T90 process, but when the alpha acid content is evaluated the difference has nothing to do with inefficiency; T45 pellets contain about double the alpha acids from the same cone hops as do T90 pellets.
This all makes more sense if the process of converting hop cones to pellets is briefly reviewed. Hops are harvested by cutting the entire bine (vine) free from the trellis and hauling this long plant into the hop processing shed. A series of specialized machines strip cones and leaves from the bine, and the cones are separated from the leaves. The cones are then loaded into the kiln, dried, and then (usually) compressed into hop bales for storage. It is imperative for hops to be harvested at just the right time and quickly processed into bales, because a delay at this stage can be detrimental to hop quality. The new bales are then transferred to cold storage where they await shipment to breweries using hop cones, or to processing plants that convert whole hops to pellets (there are a few farmers who skip the bailing process and go straight from the drying floor to the pelletizer, but this is far less common). Hop extracts are made from hop pellets (because the small, dense pellets are much easier to handle than cones).
The first step of the pellet process is converting bales into hop powder. The hop cone contains a central stem, or “strig,” that connects all of the “petals,” called bracts and bracteoles. The lupulin glands, those golden nuggets of hoppy goodness, are nestled at the base of the bracts and bracteoles. The strig is important to the hop cone because without the strig, there would be no cone or anything to hold the cone to the hop bine. But the strig has no brewing value, so it is removed before the hop cone is turned into a powder. This is where some weight is lost, and explains why T90 pellets are not T100 pellets. With T90 pellets, the bracts, bracteoles, and lupulin glands are milled into a powder, and then pressed into a pellet. The main advantages of the T90 pellet in comparison to whole hops are: Easier to handle, less costly to store and ship, improved storage properties, increased hop utilization, and easier to separate from wort. For these reasons, most breweries have migrated from whole cones to hop pellets over the last 30 years.
The T90 pellet is pretty simple and there are certainly some things about this product that can be improved. The most obvious is further removal of the parts of the pellet that have minimal brewing value. As stated above, the lupulin glands are nestled at the base of the bracts and bracteoles. If you take a hop cone and gently dissect it, you will observe that the tips of the bracts and bracteoles simply look like green petals, and you will observe that the lower portions are covered in a sticky yellow resin. The yellow, sticky stuff is really what brewers want from hops. Figure out a way to keep this stuff and minimize the non-essential parts and you have a concentrated hop pellet. In a nutshell, this is what happens when hop cones are processed into T45 pellets.
There are other things that can be done to pellets before shipping to the brewery. Pellets can be stabilized with calcium and/or magnesium, and can also be pre-isomerized. As the hop processor adds processing steps, the cost of the pellet increases, and the market for the pellet becomes smaller since not all brewers want the same sort of hop products. What this means for the homebrewer and smaller craft brewer is that access to T45 pellets, stabilized pellets, and pre-isomerized pellets is pretty limited. Any pellet hop you buy at a homebrewing store is likely a T90 pellet; if the pellet is a T45, or other further processed pellet, it will certainly be labelled as such and sold for a higher price.
The main reason that T45 pellets are used by commercial brewers is that they contain more of what is valued in hops, and less of what is not. In other words, there are economic reasons for commercial brewers to consider these pellets. Some breweries also are interested in sensory differences between T45 and T90 since the T45 pellet has less plant material. This difference is not a slam dunk benefit since hop flavor is complex, and the tannins from the “non-value” part of the cone does influence flavor. The real take-home message on this topic is that T45 pellets exist, sound really cool, but are not readily available to homebrewers. A few years ago I wanted to try using T45 pellets for aroma and started looking for sources, and was bummed out to learn that only a few varieties are readily available to commercial brewers, and these varieties are “bittering” varieties. I hope you were not getting too excited about T45 hops, but I hope understanding this the difference and process is still of value.
Q
We all know that light is bad for beer, but is all light equally bad? Are sunlight, incandescent, fluorescent, and LED lights all the same? And how much light does it take to damage wort and beer? Do I have to rack and bottle in the dark? I am also curious whether pale and dark colored beers are affected equally by light?
Chris Patterson
Downers Grove, Illinois
A
Light is not going to cause wort to go skunky, but can cause this problem with beer. This is because the light wavelengths that cause beer to skunk fall between about 350 and 550 nanometers; 350 nm is the upper end of the ultraviolet range (invisible to the human eye) and 550 nm is in the visible range. These wavelengths are associated with purple, blue, and green colors (I will get back to this later). We all know that sunlight causes beer to go skunky, and most of us have probably experienced a non-skunky beer transform into a skunk cloud on a sunny day. As far as normal light (the sorts of lights we are exposed to on a regular basis) goes, sun is the gold medal winner for skunking beer. German steins with lids were supposedly designed to prevent debris from old roofs and ceilings from falling into beer, but these lids may have also been useful for preventing skunkiness . . . antique sunglasses for beer!
Incandescent and halogen lights emit a broad spectrum of light wavelengths and are generally accepted as the most natural looking because this broad range is similar to sunlight. While these lights do emit wavelengths that cause beer to skunk, the light color is skewed toward the longer wavelengths (yellow, orange, red, and burgundy colors) that do not cause this reaction. Unlike sunlight — and incandescent and halogen bulbs — LED and fluorescent lights emit more specific wavelengths. As it turns out, most LED and all fluorescent lights both have major peaks around 400 nm. What this means to the beer lover is that LED and fluorescent lights are more apt to cause beer to go skunky than incandescent and halogen lights.
There are a few things that can be done to minimize skunkiness in the homebrewery, however. Glass carboys have many positive attributes, but the two major pitfalls are their relative fragility, and their clear nature. If you ferment and age your homebrew in glass, be careful to avoid exposure to sunlight, as well as LED and fluorescent bulbs. You should also minimize exposure to incandescent and halogen lights, but these lights do not cause most beers to go skunky. It is easy enough to cover a carboy with a towel or light blanket if you do not have space in a dark closet to shield your beer from light, and this may be something you want to do.
Stainless steel containers totally block light, so if you use stainless fermenters there are no worries. Plastics range from opaque to clear, so, depending on the plastic, light may or may not pass into your beer.
Beer color and glass color also relate to this topic. Dark beers absorb a broader spectrum of light wavelengths than lighter colored beers, so as beer becomes lighter in color, the propensity for skunkiness goes up. The same sort of thing happens with glass bottle color; brown glass absorbs the blue, purple, and green wavelengths that catalyze the skunk reaction, whereas clear, green, and blue glass all allow some, or all in case of clear bottles, of these wavelengths into the beer.
As with any chemical reaction, the rate of a reaction increases with the concentration of the participants, and also increases with the concentration of catalysts. Light is a catalyst in the skunk reaction; if light in the 350–550 nm is exposed to prone beer (anything other than black beers or beers with light stable hop compounds), the beer will eventually become skunky. Time is the part of your question that I cannot answer, but the preventative measures are pretty simple to follow. Hope this helps you in your quest for great beer!
Q
I would really appreciate some clarification concerning the sediment in the bottom of bottle-conditioned beer. Several years ago, and I can’t remember the source, I read that the sediment contained beneficial vitamin B along with antioxidants, and maybe a few other beneficial compounds. So I always swirl the last few ounces in the bottle before pouring. The other day while reading the neckband on a bottle-conditioned beer it said to pour gently so as not to disturb the sediment. Would you please give me your input on the whys or why nots about this?
Steve Fry
Kansas City, Missouri
A
Well Steve, my answer to your question is partially based on facts and partially on opinion, so let’s see if I can clear things up about this cloudy topic. Brewer’s yeast does contain B-complex vitamins, namely B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B9 (folic acid), and B7 (biotin), but does not contain B12 (cobalamin), as this vitamin is only produced by bacteria. In general terms, the nutritional properties of yeast can be manipulated by the composition of the growth media, and this technique is used to produce special nutritional yeast products for human and animal consumption; these products are specifically marketed as nutritional yeast, along with the special properties imparted to the yeast through the growth medium. Consumers may confuse the general attributes of yeast with these special products, and confer more nutritional benefits to ordinary yeast. Notwithstanding, brewer’s yeast is a good source of B-vitamins; consuming approximately 3 tablespoons (about 8 grams) of dried yeast provides the typical adult enough B-complex vitamins to satisfy the current recommended daily allowance (RDA). To put that into perspective, that’s about the amount of yeast required for a 2.5-gallon (10-L) batch of homebrew.
So, is it reasonable to conclude that consuming cloudy beer is a rich source of B-vitamins? I am going to make the crazy assumption that beer contains the same yeast density as wort after pitching. Using this assumption, you would need to drink about 2.5 liters of beer in order to consume about 25% of the RDA for B-complex vitamins (assuming a cell density in the 10 million cells/mL range). But most beers have way less yeast in the bottle than wort after pitching, usually by a factor of 5–10, so considerably more than 2.5 liters of beer are required to get 25% of the RDA for B-complex vitamins. Those are the basic facts . . . drinking cloudy beer is not a great source of B-vitamins!
OK, now for my opinion. Many food rituals are very old, and have continued into modernity with little understanding of the origin of the ritual. The ritual of swirling bottles of beer is only as old as bottled beer, and is really only practiced for certain types of beers, most notably hefeweizens. My take on the whole topic is that practice has to do with appearance and flavor, and not much more. There is certainly something visually appealing about a cloudy glass of hefeweizen crowned with a tall, fluffy, cap of foam. Since the appearance of weizens varies with the storage conditions of the bottle, and because consumers often equate changes in appearance with changes in flavor, the swirling ritual helps reset the cloudy clock. It is also a nice way of getting the last bit of beer into a glass with a rocky crown, as hefeweizens are above average in the carbonation department. Yeast sediment does have a nice bready flavor that complements the flavors of certain styles, and this certainly plays into the swirling ritual . . . if swirling the bottom resulted in a negative sensory experience, beer lovers would certainly not intentionally march down the wrong path. I am referencing hefeweizen because I think this style is the origin of the swirling ritual.
Look at the labels of many bottle-conditioned beers, notably Belgian ales from Belgium and the US, and you will see infographics showing how NOT to disturb the sediment in the bottom of the bottle. I think breweries that put these instructions on their bottles have concluded that they feel that their beers are best served without sediments, and chose to advise their consumers accordingly. Sounds like you were drinking one of those great beers. There is no right answer here as it boils down to personal preference. I say if you like the appearance and flavor of beer with the sediment added at the end of the pour, go for it, but do it for appearance and flavor, not so much the B-vitamins.
My other general opinion about this practice is probably not very popular, so I am saving the worst for last! I think that too many beer drinkers feel guilty about drinking beer because of societal pressures and attitudes. If drinking beer is a great source of vitamins, then we beer drinkers don’t have to think about beer so much as a guilty pleasure; if you have ever “argued” with yourself or others about how nutrient-rich beer is you probably understand where I am going. My column is not the place to get into the pros and cons of alcohol consumption. I believe it is important for brewers to read about alcohol and health and understand as much as possible about this complex topic, because it is far from a black-or-white debate. Looking back at some of the history related to this topic, such as the “French Paradox,” it appears that the elephant in the room was often alcohol itself; alcohol was assumed to be negative, regardless of dose, so the research focused on other components of alcoholic beverages. I will leave this topic with the following opinion . . . while unfiltered beer is not a rich source of B-vitamins, it is a rich source of pleasure when responsibly consumed. Cheers!
