13,586
edits
Changes
no edit summary
Fruit is available to the brewer in multiple different forms.
* '''Whole or sliced fresh''' - Use a CO2-purged keg or minimize headspace in a carboy. Mold and acetic acid bacteria can grow on the skins of floating fruit <ref name="kohlmorgen"></ref>. ''Brettanomyces'' can also produce acetic acid in the presence of O2, and it is possible that this is the source of acetic acid sometimes found in beers with floating fruit rather than acetic acid bacteria. Some brewers like to swirl the fermenter every few days or to keep the alcohol in contact with the fruit, though some others report no ill effects from not swirling the fermenter (and this is impractical in commercial settings). If using a barrel or larger fermenter, you may try using a punch-down technique. If punching down the fruit, purge the headspace of the vessel with CO2 to avoid oxygen exposure to the beer. Allow the fruit to get fully or possibly even over-ripe (not rotten) for best flavor. Whole fruit may take longer to ferment but it also can give the most complexity <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1123884634306416/?comment_id=1123893237638889&offset=0&total_comments=9&comment_tracking=%7B%22tn%22%3A%22R0%22%7D Thoughts from Raf Soef on using whole fruit in a MTF thread]</ref>
* '''Whole or sliced frozen''' - Bulk freezing fruit has a few main potential benefits. First, freezing fruit helps to break down cell walls, which may make the fruit easier to access for yeast and bacteria in the beer <ref>[http://www.ncbi.nlm.nih.gov/pubmed/23670237 "Effects of freezing and thawing on texture, microstructure and cell wall composition changes in papaya tissues." Phothiset S, Charoenrein S. 2014.]</ref>. Freezing fruit can also knock back reduce the microbes microbe populations present on the fruit. Note however that freezing does not kill all the microbes on the fruitand many pathogens and beer spoilers can survive freezing (freezing does not pasteurize the fruit). Finally, freezing fruit allows the brewer (especially the homebrewer) to take advantage of local and seasonal fruits when they may not have a use ready for those fruits in season. Frozen fruits are also available as IQF, or individually quick frozen fruit. IQF fruit is frozen but each berry is distinct rather than a single frozen mass. This allows for easier handling, helps prevent clumping, makes for easier fitting of fruit into small openings in carboys or barrels, and allows screening and removal of bad looking fruit. The cell walls of IQF fruit are less broken down than bulk frozen fruit, so there might be a slower extraction rate when using IQF <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1302351986459679/?comment_id=1302550736439804&comment_tracking=%7B%22tn%22%3A%22R0%22%7D Conversation about freezing fruit on MTF. 05/10/2016.]</ref>. Defrost frozen fruit in the microwave or in the fridge over night. The fruit doesn't necessarily have to come all the way up to cellaring or room temperature. Adding frozen fruit without thawing it first is probably fine as well. The beer and frozen fruit will come back up to ambient temperatures over night <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1215622131799332/?comment_id=1215820848446127&comment_tracking=%7B%22tn%22%3A%22R%22%7D Conversation with Devin Bell on MTF. 01/17/2016.]</ref>.
* '''Pureed fresh''' - pureeing fresh fruit has the benefit of extracting the fruit flavor faster. It also sinks to the bottom of the fermenter <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1172395836121962/?comment_id=1172413292786883&offset=0&total_comments=10&comment_tracking=%7B%22tn%22%3A%22R4%22%7D Conversation with Dara McMains on MTF regarding puree. 11/1/2015.]</ref>, so the problem of floating whole fruit is avoided. Puree can be difficult to rack the beer off of, and more beer may be lost compared to using whole fruit (see [https://www.facebook.com/groups/MilkTheFunk/permalink/2225127047515497/ this MTF thread] for tips on filtering out or racking off of puree as a homebrewer). Some brewers choose to heat pasteurize freshly made puree.
* '''Aseptic puree''' - Same as "Pureed Fresh", but has already been pasteurized. This is usually the case for commercially available puree. We recommend [http://www.oregonfruit.com/specialty-fruit-products Oregon Specialty Fruit], [https://www.perfectpuree.com/ The Perfect Puree], or [https://ititropicals.com iTi Tropicals] for quality commercial puree. These purees often have antioxidants such as citric and absorbic acids, cane sugar, and other juices added to them <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1308527842508760/?comment_id=1308584599169751&comment_tracking=%7B%22tn%22%3A%22R1%22%7D Conversation with Ehren Schmidt about Perfect Purees having cane sugar and acids added to them on MTF. 05/18/2016.]</ref>. Check the ingredients list of any product before ordering it. Much like fresh purees, aseptic purees or pulps may result in a fair amount of volume loss at packaging, and some puree making it into the final package can be problematic for gushing (see [https://www.facebook.com/groups/MilkTheFunk/permalink/2225127047515497/ this MTF thread] for tips on filtering out or racking off of puree as a homebrewer) <ref name='Adi mango pulp discussion'>[https://www.facebook.com/groups/MilkTheFunk/permalink/1234801133214765/ Adi mango pulp discussion]</ref>. See the [http://www.oregonfruit.com/fruit-brewing/category/brewing-with-fruit/brewing-faq Oregon Fruit webpage] for tips on usage amounts and how to use puree for brewing (they recommend 1/2 to 2 pounds of puree per gallon of finished beer). [https://www.facebook.com/groups/MilkTheFunk/permalink/1976299465731591/ Evan Coppage demonstrates how to use a tri clover compatible clamp to more easily open a bag of Oregon Fruit puree.]