ArticleKräusen Rings & Shelf Stability: Mr. Wizard Favorite Q Does the dried-up kräusen ring at the top of my fermenter after primary fermentation present a bacterial contamination risk? Daryle Sewell Frankfurt, Germany A Fermenting beer can at times appear unusualAlready a member? Log InWritten by Ashton LewisYou'll Also Like Article MEMBERS ONLY Always Question Your Instruments, Brewing Water Tweaks and Fermentation Questions Brewers put a lot of faith in their instruments . . . but are they testing them? The Wiz answers several questions on this. He also covers adjusting alkalinity in reverse osmosis water. Article FREE Feeling the Pressure, Tips for Unitank Users Mr. Wizard dives deep into the effects changing pressure can have on carbonation levels of beer. Also, a homebrewer is looking for advice on best-practices for the new unitank they recently purchased.