First let me say that it has always been a pleasure just chatting beer with you when we have met at some of the various brewing conferences over the past few years.

My question this time is the legendary cidery flavor that homebrewers have gotten from brewing with refined sugars as a significant portion of the wort. To this day, any homebrewing book that you pick up will warn against the use of sugars except for priming because of the dreaded cidery flavor. Do you have any idea of what is causing this flavor? I know of several theories by experienced brewers. For instance, Al Korzonas states in his book Homebrewing Volume 1 that although pure glucose, sucrose and partially inverted sucrose worts all had the cidery flavor, that the strongest was in the pure sucrose. This finding suggests the flavor might be due to invartase enzyme produced by the yeast. Or he goes on to say, it may be due to the lack of proper yeast nutrients in the worts.

Dan Listermann of Listermann Manufacturing has posted that in his experience, the flavor seems more associated with stale liquid malt extract. He had brewed several expired beer kits from his shelves and had used dry malt extract in lieu of sugar and still had the cidery taste. He had brewed high sucrose worts using fresh malt extract and had not experienced the cidery flavor. He suspected that the cidery flavor was nearly always present, but that in higher sugar worts, was not effectively masked by other malt character.

For myself, I only remember my very first beer being extremely cidery, and it was a high corn sugar, light beer kit. I seem to remember that my second beer was all liquid malt extract, and only had a slight cider flavor if any. I only recently started brewing with extract again, and have not experienced it at all. I wonder if the yeast may be a cause. My first beer was made with Red Star Brewing Yeast, as was the second. Do you think yeast strain may be a factor?

-John Palmer

RESPONSE:

I am glad to be back with you guys again. It helps me to refresh myself with the brewing side of fermentation. I have not seen any definitive research done on Cidery Flavor in beer. I believe both Al Korsonas and Dan Listermann are on the right track. Fermenting pure sugar: glucose, fructose and sucrose, will produce an estery, cidery, aroma. Malt tends to mask the pronounces estery aroma. The higher the % malt present, the greater the masking. Fresh malt will mask more than old, stale malt. As the malt extract ages, a maillard reaction takes place, binding the amino acids with reducing sugars. The masking effect is lessened and the nutrient value of the amino acids is bound up.

Some commercial breweries add cereal adjuncts and or pure sugar without producing the cidery flavor. The fresh malt wort and the right balance of malt with the added sugar or sugar source, masks (or prevents) any cider flavor. Low nutrients could play a role. Some work that I have done replacing malt with 25, 50 and 75% glucose indicates that you can replace a higher level of sugar and still produce a reasonably good beer when you add a rich yeast nutrient such as Fermaid K.

I would not rule out yeast strain as a factor. When you are on the borderline of wort/sugar balance and you use a very high ester producing yeast--who knows.

I will keep my eyes open for a more definitive answer.

Dr. Clayton Cone