diff -r 8853fd62ac6f -r b4bfed3684d0 www/js/prod_edit.js
--- a/www/js/prod_edit.js	Sun Dec 29 14:43:04 2019 +0100
+++ b/www/js/prod_edit.js	Fri Jan 03 15:21:22 2020 +0100
@@ -1822,7 +1822,7 @@
 
    if ((dataRecord.brew_fermenter_volume * ogx + addedmass) > 0) {
     pt = 100 * sug / (dataRecord.brew_fermenter_volume * ogx + addedmass + topw);
-    dataRecord.brew_fermenter_sg = Round(plato_to_sg(pt), 4);
+    dataRecord.og = dataRecord.brew_fermenter_sg = Round(plato_to_sg(pt), 4);
     $('#brew_fermenter_sg').val(dataRecord.brew_fermenter_sg);
     // color
     if (dataRecord.color_method == 4) {