diff -r 307640ba6ab6 -r 047ead629d4a www/includes/db_product.php
--- a/www/includes/db_product.php	Wed Feb 27 14:40:05 2019 +0100
+++ b/www/includes/db_product.php	Wed Feb 27 22:13:07 2019 +0100
@@ -502,15 +502,28 @@
 	 * SELECT, produce a list of products that can be fermented.
 	 */
 	if (isset($_GET['select']) && ($_GET['select'] == "ferment")) {
-		$query  = "SELECT code,name,uuid,stage FROM products WHERE ";
+		$query  = "SELECT code,name,uuid,stage,json_yeasts FROM products WHERE ";
 		$query .= "stage='1' OR stage='2' OR stage='3' OR stage='4' OR stage='5' OR stage='6' ORDER BY code;";
 		$result = mysqli_query($connect, $query) or die("SQL Error 1: " . mysqli_error($connect));
 		while ($row = mysqli_fetch_array($result, MYSQLI_ASSOC)) {
+			$yl = 0;
+			$yh = 40;
+			$yeasts = json_decode($row['json_yeasts'], true);
+			for ($i = 0; $i < count($yeasts); $i++) {
+				if ($yeasts[$i]['y_use'] == 0) { // Primary
+					if (floatval($yeasts[$i]['y_min_temperature']) > $yl)
+						$yl = floatval($yeasts[$i]['y_min_temperature']);
+					if (floatval($yeasts[$i]['y_max_temperature']) < $yh)
+						$yh = floatval($yeasts[$i]['y_max_temperature']);
+				}
+			}
 			$brews[] = array(
 				'code' => $row['code'],
 				'name' => $row['name'],
 				'uuid' => $row['uuid'],
-				'stage' => $row['stage']
+				'stage' => $row['stage'],
+				'yeast_lo' => $yl,
+				'yeast_hi' => $yh
 			);
 		}
 		header("Content-type: application/json");