diff --git a/init.lua b/init.lua
index e2ba69d..155c139 100644
--- a/init.lua
+++ b/init.lua
@@ -1,5 +1,11 @@
 local reg_items = minetest.registered_items
 
+local revealed_cache = {}
+
+minetest.register_on_leaveplayer(function(player)
+	revealed_cache[player:get_player_name()] = nil
+end)
+
 local function item_has_groups(item_groups, groups)
 	for i = 1, #groups do
 		local group = groups[i]
@@ -11,30 +17,43 @@ local function item_has_groups(item_groups, groups)
 end
 
 local function revealed_show_recipe(recipe, playername)
+	if not revealed_cache[playername] then
+		revealed_cache[playername] = {}
+	end
+	if revealed_cache[playername][recipe] then
+		return true
+	end
+
 	local revealed = doc.data.players[playername].stored_data.revealed
 	for _, item in pairs(recipe.items) do
-		local is_revealed_item
+		local is_revealed_item = false
 		if item:sub(1,6) == "group:" then
 			local groups = item:sub(7):split(",")
 			for cid, items in pairs(revealed) do
 				for revealed_item in pairs(items) do
 					if reg_items[revealed_item] and item_has_groups(reg_items[revealed_item].groups, groups) then
 						is_revealed_item = true
+						break
 					end
 				end
+				if is_revealed_item then
+					break
+				end
 			end
 		else
 			for cid, items in pairs(revealed) do
 				if items[item] then
 					is_revealed_item = true
+					break
 				end
 			end
 		end
 
 		if not is_revealed_item then
-			return
+			return false
 		end
 	end
+	revealed_cache[playername][recipe] = true
 	return true
 end