Dear Mr. Wizard,
Help! I have been brewing for about 10 years and have just taken the step to all-grain. I have been reading and trying many of the recipes in BYO, and as long as I stay with extracts or partial mash, I am very close to the OGs. But when I do an all-grain batch, I am about ten points below the target OG. I know I can correct this with some DME, but I don’t want to. When you publish recipes, is it assumed that the brewer knows enough to adjust for mash efficiency, or are they already adjusted to some unknown mash efficiency? I run into the same problem with other books and publications.
John “Mick” Barnes
Marcellus, New York
Mr. Wizard replies:
The recipes published in Brew Your Own and in other magazines and books are indeed formulated with some efficiency in mind. In the case of regular columns, such as “Replicator,” the columnist typically will use his own efficiency factor, based on his system and experience. This is usually between 65 and 68 percent, meaning that a pound of malt will add between 0.65 and 0.68 pounds of extract to the wort. Other recipes are submitted by readers, and it is difficult to know what the brewer had in mind.
I am occasionally asked to review reader recipes. When I review them I begin by checking if the malt (or other sources of extract, when applicable) contributes enough extract to hit the target gravity. In order to do this, some assumption about efficiency must be made, and I personally use between 65 and 68 percent. Sometimes the malt list doesn’t match the original gravity and the amount of the primary extract source (usually some type of pale malt for all-malt brews) needs to be increased in order to improve the odds of hitting the target gravity.
When I use other brewers’ recipes I look at the malts, their relative proportions and the original gravity. I then re-calculate the recipe based on my own brewing system and, to a large extent, ignore some of the finer details of the recipe. I use a certain mash thickness that works for my system, I get a particular yield influenced by my mill and my mash and lauter vessels, I have certain mash profiles that I like, I typically boil wort in a particular fashion and so on. I imagine that most brewers merge a recipe into their standard procedure in a similar way.
It sounds to me that your system consistently has an efficiency less than that used by most homebrew publications when they check the accuracy of recipes. If I were you, I would adjust recipes by focusing on the pale malt (or other primary source of extract). You may find that simply increasing the amount of pale malt by 20 percent over what is listed in the recipe works out. You may also want to examine the coarseness of your malt. Overly coarse grist may be one of the culprits behind your low yield problem and simply using a finer grist may help out considerably. Regardless of how much tweaking and tuning a brewer does to his system, it will never be able to exactly produce 5 gallons of wort at a target original gravity using a recipe based on another brewer’s system unless some modifications are made to the recipe. You could also check out a brewing-calculation software program like ProMash, which makes it easier to adjust base-malt amounts to match target gravities on a given system.
Dear Mr. Wizard,
Over the years I have read a number of articles on dry-hopping and hopback use. As I understand it, dry- hopping should not be done in the primary fermenter because the “scrubbing action” of the yeast activity will diminish the desired results of dry-hopping. At the same time, most articles on hopbacks say the unit should process the hot wort directly from the boiling kettle so that the high heat helps to sanitize the hops and to extract the hop oils. But now the wort is in the primary (cooled, of course) and subject to that same “scrubbing action” mentioned earlier! I would appreciate any information you might provide to clear up these issues.
Dude Green
Yuba City, California
Mr. Wizard replies:
Most brewing techniques are touted by a long list of advantages. Dry-hopping, which means adding compressed hop cones or hop pellets to beer or fermenting beer, can be “sold” by its ability to contribute a nice, fresh hop aroma. Why put hops in the kettle or use a hopback when you can add them straight to the fermenter?
Hopback advocates almost always mention the bonus of having the hops and the hopback sanitized in the process. This casts a cloud over the method of dry-hopping, because it implies that hops are covered in bacteria and require sanitization (an argument that is not well supported). Dry-hoppers feel pretty confident about the method — after all, dry-hopping would not be popular if it routinely produced contaminated beer. Plus, dry-hoppers avoid the “scrubbing” action of primary fermentation.
When reading the hype surrounding these methods, it is hard to get a feel for the salient features of each method. When I want a really hoppy beer with a fresh hop oil aroma, I prefer dry-hopping. The aroma of dry-hopped beer is often described as grassy and frequently has the distinct aroma of myrcene (a particularly aromatic hop oil). Hopping rates vary depending on the hop variety and oil content, but 1/4 to 1/2 to ounce of hops per gallon of beer is a pretty normal range for dry-hopping. When I dry-hop, I do it after primary fermentation is complete and before moving the beer to a cool location for aging.
But I personally prefer adding hops to hot wort, usually in the kettle at the end of the boil for most beer styles, because the grassy and oily aromas are less pronounced. The little brewery up Highway 99 from you is well known for the hoppy aroma of its brews, especially its Pale Ale. Sierra Nevada uses a generous late-hop addition in all of its standard beers and only dry-hops the Celebration and Bigfoot. Hops added late in the boil or to a hopback can certainly produce a very hoppy beer, but the hop aroma is less “raw” in comparison to dry-hopped beers. Hopping rates for late-hop additions and hop-back additions vary, but 1/4 to 1/2 ounce per gallon will produce beers with pronounced hop aroma.
By the way, some commercial brewers use in-line hopping devices that are similar to the typical homebrew hopback. Many commercial hopbacks are vented — they’re like big strainers placed between the brew kettle and the wort cooler — but the in-line devices aren’t vented. This means the grassy and oily aromas are extracted from the hops but do not escape from the wort. This method produces an aroma more similar to a dry-hopped beer. The purported advantages are that the hops are sanitized, more oils are extracted because the wort is hot and the hops do not have to be fished from the fermenter after they are spent. But the aroma is still “scrubbed” during fermentation.
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