{"id":7862,"date":"2025-12-10T17:17:25","date_gmt":"2025-12-10T17:17:25","guid":{"rendered":"https:\/\/www.caffecampetelli.com\/coffee-blog\/selected-beans-vs-defective-beans-how-to-read-sieve-and-defects-in-green-coffee\/"},"modified":"2025-12-10T17:37:23","modified_gmt":"2025-12-10T17:37:23","slug":"selected-beans-vs-defective-beans-how-to-read-sieve-and-defects-in-green-coffee","status":"publish","type":"post","link":"https:\/\/www.caffecampetelli.com\/en\/coffee-blog-en\/selected-beans-vs-defective-beans-how-to-read-sieve-and-defects-in-green-coffee\/","title":{"rendered":"Selected beans vs defective beans: how to read sieve and defects in green coffee"},"content":{"rendered":"\n<figure class=\"wp-block-image aligncenter size-large\"><a href=\"https:\/\/www.caffecampetelli.com\/wp-content\/uploads\/2025\/12\/Caffe-verde-caffe-difettoso.webp\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"https:\/\/www.caffecampetelli.com\/wp-content\/uploads\/2025\/12\/Caffe-verde-caffe-difettoso-1024x576.webp\" alt=\"\" class=\"wp-image-7854\" srcset=\"https:\/\/www.caffecampetelli.com\/wp-content\/uploads\/2025\/12\/Caffe-verde-caffe-difettoso-1024x576.webp 1024w, https:\/\/www.caffecampetelli.com\/wp-content\/uploads\/2025\/12\/Caffe-verde-caffe-difettoso-500x281.webp 500w, https:\/\/www.caffecampetelli.com\/wp-content\/uploads\/2025\/12\/Caffe-verde-caffe-difettoso-700x394.webp 700w, https:\/\/www.caffecampetelli.com\/wp-content\/uploads\/2025\/12\/Caffe-verde-caffe-difettoso-300x169.webp 300w, https:\/\/www.caffecampetelli.com\/wp-content\/uploads\/2025\/12\/Caffe-verde-caffe-difettoso-768x432.webp 768w, https:\/\/www.caffecampetelli.com\/wp-content\/uploads\/2025\/12\/Caffe-verde-caffe-difettoso-1536x864.webp 1536w, https:\/\/www.caffecampetelli.com\/wp-content\/uploads\/2025\/12\/Caffe-verde-caffe-difettoso-533x300.webp 533w, https:\/\/www.caffecampetelli.com\/wp-content\/uploads\/2025\/12\/Caffe-verde-caffe-difettoso.webp 1920w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><figcaption class=\"wp-element-caption\"><em>Comparison of screen-sorted grains with absence of primary and secondary defects on the left and poor-quality grains with presence of primary and secondary defects on the right<\/em><\/figcaption><\/figure>\n\n<h2 class=\"wp-block-heading alignfull\">What is sieve (screen size) and why it affects yield<\/h2>\n\n<p><em>Sieve<\/em> means <strong>grain size calibration<\/strong> expressed in sixty-fourths of an inch (e.g., 15\/64, 17\/64, 18\/64). Uniform selection allows: <\/p>\n\n<ul class=\"wp-block-list\">\n<li><strong>Smoother roasting<\/strong>: grains of similar size receive the same heat and develop consistent flavors.<\/li>\n\n\n\n<li><strong>More predictable extraction<\/strong>: grinding, flow and solubility are more consistent.<\/li>\n\n\n\n<li>Less <strong>waste<\/strong>: fewer grains that are too small or &#8220;elephant&#8221; roasting differently.<\/li>\n<\/ul>\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>Practical directions: highland washed origins often have riddles <strong>16-18<\/strong>; naturals and some lower-altitude Arabicas show more variability.<\/p>\n<\/blockquote>\n\n<p class=\"has-text-align-center\">For extraction profiles and yield by method, read our guide <a href=\"https:\/\/www.caffecampetelli.com\/tag\/cialde-ese-44-mm-compatibilita-cialde-espresso-a-casa-cialde-compostabili\/\" data-type=\"post_tag\" data-id=\"246\" target=\"_blank\" rel=\"noreferrer noopener\">to 44mm ESE wafers<\/a><\/p>\n\n<h2 class=\"wp-block-heading alignfull\">Primary and secondary defects: what they are in practice<\/h2>\n\n<p>The term <em>defect<\/em> indicates a <strong>nonconformity of the grain<\/strong> that can alter aroma, taste, body, and cleanliness. Operationally, two families are distinguished: <\/p>\n\n<h3 class=\"wp-block-heading\">Primary defects (high impact in cup)<\/h3>\n\n<ul class=\"wp-block-list\">\n<li><strong>Black\/fermented beans<\/strong> (black, sour): unpleasant, burnt or acid-acetic notes.<\/li>\n\n\n\n<li><strong>Fungus\/mold<\/strong>: off-flavors earthy, stale.<\/li>\n\n\n\n<li><strong>Foreign bodies<\/strong> (stones, small wood, parchment peels\/chips): mechanical hazards, pest flavors.<\/li>\n\n\n\n<li><strong>Severe insect damage<\/strong>: loss of substance, irregular extractions, bitter notes.<\/li>\n<\/ul>\n\n<h3 class=\"wp-block-heading\">Secondary defects (average impact, cumulative)<\/h3>\n\n<ul class=\"wp-block-list\">\n<li><strong>Broken or chipped grains<\/strong>: roast faster, increase bitterness.<\/li>\n\n\n\n<li><strong>Quakers (immature\/clear grains)<\/strong>: incomplete development, flat and &#8220;papery&#8221; profile.<\/li>\n\n\n\n<li><strong>Lightly stung grains<\/strong> (insects): unstable extraction, reduced body.<\/li>\n\n\n\n<li><strong>Shells, elephant beans<\/strong>: anomalous shapes, disuniformity in roasting.<\/li>\n\n\n\n<li><strong>Parchment\/silver residues<\/strong>: possible dry or astringent notes.<\/li>\n<\/ul>\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>In summary: <strong>a few primary flaws<\/strong> are enough to undermine the cup; the <strong>secondary<\/strong> ones weigh when they add up.<\/p>\n<\/blockquote>\n\n<h2 class=\"wp-block-heading alignfull\">How to recognize them by looking at the picture<\/h2>\n\n<p><strong>Left (selected)<\/strong>: uniform green color, homogeneous sieve, intact surfaces; no black grains, sour beans, obvious breaks.<\/p>\n\n<p><strong>Right (defective)<\/strong>: strong <strong>heterogeneity<\/strong> in size and color; presence of black\/fermented, broken, shell, immature grains; residues and foreign bodies visible.<\/p>\n\n<h2 class=\"wp-block-heading alignfull\">Effects in roasting and extraction<\/h2>\n\n<p><strong>Heat uniformity<\/strong>: selected batches react predictably to stages (drying, Maillard, first crack). Batches with many defects require corrective profiles and often give unbalanced cups. <\/p>\n\n<p><strong>Aromatic cleaning<\/strong>: <strong>fewer<\/strong> defects \u2192 <strong>less off-flavors<\/strong> (soil, cardboard, vinegar, ash).<\/p>\n\n<p><strong>Body and sweetness<\/strong>: proper selection and maturation \u2192 <strong>more developed sugars<\/strong> and <strong>controlled bitterness<\/strong>.<\/p>\n\n<p>If you encounter recurring problems in the cup, consult <a href=\"https:\/\/www.caffecampetelli.com\/en\/coffee-blog-en\/troubleshooting-ese-pods-15-common-problems-and-quick-fixes\/\" target=\"_blank\" rel=\"noreferrer noopener\">ESE wafer troubleshooting<\/a><\/p>\n\n<h3 class=\"wp-block-heading alignfull\">Examples of defects and impact in the cup<\/h3>\n\n<section aria-labelledby=\"difetti-caffe-tab\" style=\"margin:1rem 0;\">\n<h2 id=\"difetti-caffe-tab\" style=\"margin:0 0 .5rem 0; font-size:1.25rem;\">Defects of green coffee: examples and sensory impact<\/h2>\n<div style=\"overflow-x:auto; -webkit-overflow-scrolling:touch;\">\n<table style=\"width:100%; border-collapse:collapse; table-layout:fixed; background:#fff; border:1px solid #ececec;\">\n<thead>\n<tr>\n<th scope=\"col\" style=\"padding:12px; border:1px solid #ececec; text-align:left; background:#fafafa;\">Defect<\/th>\n<th scope=\"col\" style=\"padding:12px; border:1px solid #ececec; text-align:left; background:#fafafa;\">Category<\/th>\n<th scope=\"col\" style=\"padding:12px; border:1px solid #ececec; text-align:left; background:#fafafa;\">Effect in roasting<\/th>\n<th scope=\"col\" style=\"padding:12px; border:1px solid #ececec; text-align:left; background:#fafafa;\">Effect in cup<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"padding:12px; border:1px solid #ececec;\">Black\/fermented beans<\/td>\n<td style=\"padding:12px; border:1px solid #ececec;\">Primary<\/td>\n<td style=\"padding:12px; border:1px solid #ececec;\">Burnt risk, uneven curves<\/td>\n<td style=\"padding:12px; border:1px solid #ececec;\">Aggressive bitterness, acetic, unpleasant odors<\/td>\n<\/tr>\n<tr style=\"background:#fafafa;\">\n<td style=\"padding:12px; border:1px solid #ececec;\">Mold\/fungus<\/td>\n<td style=\"padding:12px; border:1px solid #ececec;\">Primary<\/td>\n<td style=\"padding:12px; border:1px solid #ececec;\">Irregular development<\/td>\n<td style=\"padding:12px; border:1px solid #ececec;\">Earthy, stale, persistent defect<\/td>\n<\/tr>\n<tr>\n<td style=\"padding:12px; border:1px solid #ececec;\">Broken\/chipped<\/td>\n<td style=\"padding:12px; border:1px solid #ececec;\">Secondary<\/td>\n<td style=\"padding:12px; border:1px solid #ececec;\">Toasted too quickly<\/td>\n<td style=\"padding:12px; border:1px solid #ececec;\">Astringency, early bitterness<\/td>\n<\/tr>\n<tr style=\"background:#fafafa;\">\n<td style=\"padding:12px; border:1px solid #ececec;\">Quakers (immature)<\/td>\n<td style=\"padding:12px; border:1px solid #ececec;\">Secondary<\/td>\n<td style=\"padding:12px; border:1px solid #ececec;\">Chronic underdevelopment<\/td>\n<td style=\"padding:12px; border:1px solid #ececec;\">Flat, papery, little sweetness<\/td>\n<\/tr>\n<tr>\n<td style=\"padding:12px; border:1px solid #ececec;\">Shell\/elephant beans<\/td>\n<td style=\"padding:12px; border:1px solid #ececec;\">Secondary<\/td>\n<td style=\"padding:12px; border:1px solid #ececec;\">Abnormal heat reception<\/td>\n<td style=\"padding:12px; border:1px solid #ececec;\">Unevenness, aromatic imbalances<\/td>\n<\/tr>\n<tr style=\"background:#fafafa;\">\n<td style=\"padding:12px; border:1px solid #ececec;\">Foreign bodies<\/td>\n<td style=\"padding:12px; border:1px solid #ececec;\">Primary<\/td>\n<td style=\"padding:12px; border:1px solid #ececec;\">Mechanical hazards\/contamination<\/td>\n<td style=\"padding:12px; border:1px solid #ececec;\">Off-flavors, coffee grinder hazard<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/section>\n\n<h2 class=\"wp-block-heading alignfull\">How we work at Caff\u00e8 Campetelli: selection and quality control<\/h2>\n\n<p><strong>Selection by sieve<\/strong>: consistent batches for repeatable roasts.<\/p>\n\n<p><strong>Critical defect rejection<\/strong>: visual and mechanical checks before roasting.<\/p>\n\n<p><strong>Profiling and<\/strong> cupping: in-cup testing to confirm sweetness, body and cleanliness.<\/p>\n\n<p><strong>Transparency<\/strong>: we communicate sensory profiles and extraction recommendations at home.<\/p>\n\n<h2 class=\"wp-block-heading alignfull\">FAQ on green coffee<\/h2>\n\n<h3 class=\"wp-block-heading alignfull\">Is the bigger sieve always better?<\/h3>\n\n<p>No. <strong>Sieve<\/strong> (screen size) measures grain size, but quality depends primarily on <strong>uniformity, ripeness, and absence of defects<\/strong>. Large sieves (e.g., 17-18) can promote <strong>slower roasting and full body<\/strong>, but only if the grains are <strong>uniform<\/strong> and well ripened. A &#8220;mixed&#8221; batch (14-18) roasts unevenly: small ones cook too fast, large ones lag behind, with unbalanced cups.   <\/p>\n\n<h3 class=\"wp-block-heading alignfull\">Which defects spoil the cup most?<\/h3>\n\n<p>The most devastating are the <strong>primary defects<\/strong>: <strong>black\/fermented grains (black\/sour)<\/strong>, <strong>mold\/fungus<\/strong>, and <strong>foreign bodies<\/strong>. Even a <strong>few such grains<\/strong> can overpower the entire extraction. <\/p>\n\n<ul class=\"wp-block-list\">\n<li><strong>Black beans (black beans)<\/strong><br\/>Caused by out-of-control rotting\/fermentation or poorly done drying. In roasting they develop tar\/ash notes, aggressive bitterness and unpleasant persistence. It only takes 2-3 beans in 250 g to perceive distinct defects in the cup.  <\/li>\n\n\n\n<li><strong>Sour beans (sour-fermented)<\/strong><br\/>Often due to sour cherries or acid fermentation. They give volatile &#8220;acetic&#8221; acidity, pungent sourness, lean body and messy profile. They easily contaminate the batch.  <\/li>\n\n\n\n<li><strong>Mold\/fungus (moldy\/musty)<\/strong><br\/>Derived from wet storage or slow drying. Earthy, stale, &#8220;wet closet&#8221; aromas, very persistent and difficult to mask with roasting. <\/li>\n\n\n\n<li><strong>Foreign bodies (stones, wood, thick parchment)<\/strong><br\/>In addition to the mechanical hazard to the coffee grinder, they release off-flavors (dust, wood, soil) and soil the profile.<\/li>\n<\/ul>\n\n<h3 class=\"wp-block-heading alignfull\">Quakers can be seen after roasting: is it a problem with the green?<\/h3>\n\n<p>Yes. <strong>Quakers<\/strong> are <strong>immature<\/strong> beans (picked unripe or poorly selected) that, even when roasted properly, <strong>do not brown<\/strong>: they remain clear\/beige. The cause is in <strong>green coffee<\/strong>: low ripeness = lower sugars and Maillard precursors \u2192 during roasting they develop little color and few flavor compounds.  <\/p>\n\n<h3 class=\"wp-block-heading alignfull\">Can I &#8220;save&#8221; a coffee with many defects by adjusting the extraction?<\/h3>\n\n<p>Only partially. Extraction adjustments can <g id=\"gid_0\">mitigate<\/g> some effects (bitterness, pungent acidity, thinness), but the <g id=\"gid_1\">primary defects<\/g> (black\/fermented, mold\/fungus, foreign bodies) <g id=\"gid_2\">remain noticeable<\/g>. If the batch is really compromised, the real solution is to <strong>change raw materials<\/strong>. That said, here&#8217;s what you can do to limit the damage.   <\/p>\n\n<h3 class=\"wp-block-heading alignfull\">How can I tell if a mixture has been selected well?<\/h3>\n\n<p>Look for <strong>transparency<\/strong> about origins, consistency between batches, clear sensory profiles, and <strong>consistency<\/strong> in the cup. At home, check for creaminess, sweetness, and cleanliness. <\/p>\n","protected":false},"excerpt":{"rendered":"<p>What is sieve (screen size) and why it affects yield Sieve means grain size calibration expressed in sixty-fourths of an inch (e.g., 15\/64, 17\/64, 18\/64). Uniform selection allows: Practical directions: highland washed origins often have riddles 16-18; naturals and some lower-altitude Arabicas show more variability. For extraction profiles and yield by method, read our guide [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":7861,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[239],"tags":[],"class_list":["post-7862","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-coffee-blog-en"],"blocksy_meta":[],"_links":{"self":[{"href":"https:\/\/www.caffecampetelli.com\/en\/wp-json\/wp\/v2\/posts\/7862","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.caffecampetelli.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.caffecampetelli.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.caffecampetelli.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.caffecampetelli.com\/en\/wp-json\/wp\/v2\/comments?post=7862"}],"version-history":[{"count":2,"href":"https:\/\/www.caffecampetelli.com\/en\/wp-json\/wp\/v2\/posts\/7862\/revisions"}],"predecessor-version":[{"id":7872,"href":"https:\/\/www.caffecampetelli.com\/en\/wp-json\/wp\/v2\/posts\/7862\/revisions\/7872"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.caffecampetelli.com\/en\/wp-json\/wp\/v2\/media\/7861"}],"wp:attachment":[{"href":"https:\/\/www.caffecampetelli.com\/en\/wp-json\/wp\/v2\/media?parent=7862"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.caffecampetelli.com\/en\/wp-json\/wp\/v2\/categories?post=7862"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.caffecampetelli.com\/en\/wp-json\/wp\/v2\/tags?post=7862"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}