Preventing scorched wort and burnt flavor in your beer
After a long brew day and weeks of eager anticipation, there are few things more devastating to a brewer than discovering an unwanted microbial infection or tasting burnt/smokey notes in your latest brew. The BIAC does most of the work for you in preventing the unwanted infection, (by boiling in the fermenter it is heat sanitized), however, one needs to be careful in direct-fired (gas or electric) systems to ensure that scorching on the pot or element does not occur. Scorching is most likely to occur with 'gummy' cereals such as rye, oat and wheat, and when a large amount of solid matter settles against or even passes the heating surface without enough water present to dissipate the heat. This is most likely to occur at three different points in the brewing process; during mashing, if a lot of grain particulate is lost through the false bottom and settles on the element, during the boil if a lot of hop pellets are added at once or if malt extract is used and not fully dissolved prior to adding to the boil kettle, or during fermentation if the element is improperly used for heating and the element scorches the yeast that has settled on the element.Fortunately, by taking the following cautionary steps you can prevent scorching. The risk can be mitigated or eliminated altogether by following these steps:
- Use the Power Controller to limit power output when there is the highest risk of scorching. During mashing, the element can be kept to 20-30% output (this lowers the watt density of a 100W/in² element down to 20-30W/in²). During mashing in or raising or moving the Colander (when the movement might cause more grain to settle through the false bottom) the element should be turned off. When adding pelletized hops, they should be broken down and dissolved before adding to the boil. During fermentation, the power output should be always kept below 3%.
- Don’t use too small of a crush. A fine crush is tempting, because sugar extraction is quicker, but it produces a lot of powder that settles on the element and can scorch, particularly during mashing in. Use a wider roller crush of 0.040-0.048” roller gap and use rice hulls to improve bed fluidity. You may need to extend your mash period a little, but the larger crush also helps improve vorlauf/lautering. And remember to lower or turn the element off when raising the Colander as the bumping may cause grain to settle through.
- Don't overmix your mash and don't mix near the bottom of the Colander (this may break up the grain more than is needed, and may force grain through the false bottom where it can settle on the element).
- Keep the element clean. If not properly cleaned after each brew, particularly on the element, sediment can start to build up and will scorch and can damage or ruin the heater. Once an area of the element has started to scorch, it seems to spreads quickly until the entire element is coated (similar to how scorching on the bottom of a pot generally covers the entire bottom). For cleaning the element, chemical cleaners can be used, but we have found a hardened cotton scrubby such as the 'EuroScrubby' to be normally sufficient. If that doesn’t get it clean, a 100% copper, Chore Boy scrub brush or stainless steel safe scrub pad can be effective.
- Do not use high watt density heating elements (BREWHA heaters are low watt density but hardware store purchased heaters are most often high watt). The watt density can be calculated by dividing the maximum wattage of an element, by the surface area. Watt density should be below 110W/in². High watt density elements are appealing because they are smaller so can fit in smaller vessels, but the risk of scorching is too high. (Picture at right shows scorching on non-fold back type element.)
Many thousands of batches have been successfully brewed with BREWHA electric heating elements so by taking a few cautionary steps, ‘Cigarette beer’ can be avoided. If troubles do arise, tasting your wort throughout the brew session can help pin point the problem to avoid it in the future.
(A special thank you to customer Brian R for submitting the picture, and Ron H for the questions.)