Changes

"Contact time" in the table below is for mixed fermentations with [[Brettanomyces]]. Kettle sours or beers that do not contain live ''Brettanomyces'' can have a much shorter fruit contact time (generally 1-2 weeks). All contact times are assumed to be applied in secondary, and at the end of aging. Keep in mind that this is just a general guideline for usage amounts. Brewers should consider their base beer's characteristics such as abv, flavor profile, acidity levels, etc. when considering how much fruit to add. It is common for lambic brewers to age much higher fruit to beer ratios and then blend back with unfruited lambic to the desired g/L amount. If you are really trying to nail the perfect fruit amount, applying this sort of technique could be useful (assuming you have suitable beers around to blend back). This will allow you to try different blend ratios to determine the appropriate amount of fruit for your beer and desired outcome. In regard to fruit ratios, Belgians calculate fruit ratios by : Fruit ratio (g/l) = (KG of Fruit / (KG of fruit + liters of beer))*1000 <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1186714508023428/?comment_id=1186801048014774&reply_comment_id=1187308741297338&comment_tracking=%7B%22tn%22%3A%22R2%22%7D MTF Facebook comment from Raf about fruiting ratios]</ref>. Fruit displacement isn't a huge concern; 10 pounds of fruit generally requires an extra gallon of headspace (the exact volume depends on the volume of the fruit <ref name="fruit_displacement_wikipedia" />). However, the fruit will usually re-ferment, causing a blow off, so allowing for extra headspace is a good idea. [http://www.aqua-calc.com/calculate/food-volume-to-weight This site] might assist with calculating the displacement volume of fruit. Maintain a temperature range from 65-75°F (18-24°C) during the fermentation of the fruit if possible, however, temperature swings during fruit fermentation are generally more forgivable than when temperatures swing during primary fermentation.