An Exquisite Thermo Sudoku

** TODAY'S PUZZLE **
Florian Wortmann wowed us just a few days ago with a minesweeper/yin-yang/sudoku hybrid and he returns tonight with a simply exquisite thermo sudoku - check out the symmetry in this grid! And it has 1 star for difficulty so it's nearly genuinely approachable ;)
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Rules:
Normal sudoku rules apply. Digits along a thermometer increase from the bulb end.
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▶ Contents Of This Video ◀
0:00 Theme music & puzzle reveal
2:30 Check out our Thermo Sudoku App
2:48 Patreon winner for June!
3:57 New crossword video
4:09 Happy birthdays and marriages!
5:26 Rules
6:08 Start Of Solve - Let's Get Cracking!
26:34 Roll Of Honour For June Competition
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(Please note to use our real names rather than 'Cracking The Cryptic'.)
▶ SUDOKU PAD - Use Our Software For Your Puzzles ◀
You can input classic sudoku puzzles into our software and help support Sven, the programmer responsible for the wonderful user interface we all use to play these puzzles everyday. The app also comes with 12 handmade puzzles from us:
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[@FlorianWortmann]

Wow, what a nice surprise and a wonderful solve! Being compared with Aad is quite an accolade. Thanks for the kind words, Simon. It's funny... there have been some amazing thermo sudokus by Aad on the channel in recent months, and I wanted to set something similar. I was quite amazed when I discovered this symmetrical arrangement, and that it proved to be approachable and interesting at the same time.

[@davidrattner9]

More loveliness from you Florian!!

[@longwaytotipperary]

Approachable and interesting are my very favorites!!!! 😃

[@Anne_Mahoney]

Very nice puzzle: I love the highly symmetrical ones.

[@coltith7356]

This is the first puzzle that I've been able to solve on my own without help so I'm incredibly grateful to you for creating it, it taught me a lot and it contained extremely enjoyable and satisfying deductions for someone like me. So once again, thank you very much for the time you spend creating these amazing puzzles.

[@FlorianWortmann]

@@coltith7356 Thank you so much for the kind comment! I'm glad you were able to solve the puzzle and enjoyed it that much :-)

[@dukedragon28]

After just over 2 Hours, I solved this as my first Variant Sudoku. Now its time to watch Simon do it in a quarter of that

[@godfoca]

Simon not noticing the 2/4 and 7/9 pairs that limit R3C2/R3C8 and R7C2/R7C8 after deducting how the outer thermos work is peak Simon.

[@liiiinder]

18:17 if only you realised the 24 and the 68 pairs in the columns actually took away the middle digit from the start and end aswell you would have filled both termos here

[@itsmeagain1745]

He missed it from 13 min. Removing the middle digits from the group - even saying them out loud and still didn't realise he had pairs.

[@Mephistahpheles]

I find his focus incredible. That he even highlighted the 24 pair (@13:22) while studying the thermo logic and missing the Sudoku logic. No doubt that focus allows him to find solutions of incredible depth. My approach (I'm far from a pro at these) is more "width"....finding relatively shallow solutions but at intersections between rule sets.

[@koepisking]

I wonder if the day will come where the puzzles you solve progressively get harder throughout the week. 1 star Monday, 3 star Wednesday and 5 star on friday.

[@acantilado]

Agree! Friday/Saturday is the best time for an epic 2 hour “movie”!

[@chuckmanion1128]

29:06 I really enjoy thermos. Was a little slow because I missed something obvious for way too long, but it was definitely one of my favorite thermos so far.

[@sonnenstrahlen2037]

What a beautiful music accompanying the Roll of Honour! May I ask the name of it?

[@davidh.4944]

39:20@#8961. This is the best kind of sudoku, IMO. No mind-bending maths, no irritating set theory break-in, no hunt-in-vain- for-an-hour- looking-for-that- one-key-deduction, just a clean, approachable puzzle that keeps you working steadily to the end. Very nice.

[@MyriamTT]

A great puzzle, for normal people, for a change. Thank you !!! Friday puzzles should always be easier.

[@michaelmatter1222]

Ah thermos, my first love in the world of variant sudoku 💙 A very delightful puzzle indeed!

[@bobblebardsley]

Goodliffed it to the max and solved it in 22:51 (probably one of my best ever, I normally go wrong on thermos because I get the logic backwards and think "if it ends in a 9, the penultimate cell MUST be an 8" etc). Loved the symmetry and all the pairs that kept appearing from nowhere.

[@humanbirdsong]

I’m so impressed with how quickly you found the beautiful tricks here! I think I fiddled about for a good 10 minutes on LMD before understanding how to proceed without resorting to excessive marking.

[@JeffreyLByrd]

I had a rather slow time compared to many of the other posters (41 mins and some odd). It took me a while to appreciate the fact that the two long thermos only worked if they were both consecutive, one with min values and one with max values. Once I got that it all unraveled nicely. I just wish I hadn’t had to stare at it for 20 mins to get that.

[@longwaytotipperary]

What a wonderful puzzle!!! My brain particularly appreciates the totally understandable rule set after yesterday’s puzzle. I spent another hour after yesterday’s puzzle wrapping my brain around what was being indexed by the friendly digits and gave myself a headache. 😬 So my brain thanks you and I thank you! I vote for the occasional not-so-difficult, but interestingly tricky puzzles!! Thank you Florian for providing that puzzle today!!! ❤️❤️❤️

[@davidrattner9]

I appreciate your brain constantly for chiming in and being part of this community. ❤❤❤

[@airwalkalman]

You typed the words right out of my brain

[@longwaytotipperary]

@@davidrattner9 my brain says thank you! 😁❤️❤️

[@longwaytotipperary]

@@airwalkalman 😄

[@HunterJE]

Another way to describe the logic Simon gets in to around 12:00 to remove middle values that feels less roundabout is that the thermo with the 4 its "elbow" forces max values along its full length- in other words, not only is the final digit on that thermo 9, the penultimate digit is 8. Given the 6789 quadruple, this forces the opposite thermo to end 67 which are minimum values.

[@HunterJE]

Also agh could have skipped a lot of steps by noticing the middle values were excluded on tips and bulbs as well...

[@57thorns]

@@HunterJE Yes, just by looking at the 24 and 68 pairs at 13:24 🙂

[@MsNosis]

pencil marking everything was the one thing that helped me notice all hidden quadrupels and triplets in this puzzle. very difficult puzzle but fun one

[@Ryan-1704]

Of course we want a 2 hour video every day! The ones I can solve like this one are great too though

[@Ennar]

Very clean puzzle! Love the central symmetry, it's absolutely beautiful that a unique solution exists without a given digit!

[@l3igl2eaper]

I got fairly far into the solve before getting stuck but after a few minutes, I saw some very nice logic on the extreme columns (and what happens to the corner boxes) and I solved in just over 20 minutes. Very nice Thermo Sudoku!

[@davidrattner9]

So glad you cherished this Simon. Your enthusiasm, love always shines bright..no matter if 30 min solve or 2 hour epic.

[@cruiseqe2]

Please could you tell us what music was being played during the roll of honour? It is beautiful.

[@ferociousbiscuit]

I'm not sure what it is but if you like this you'll probably "Keys of Moon" and "Yiruma"

[@cruiseqe2]

@@ferociousbiscuit Both of those are excellent suggestions. Thank you. I did try Shazamming the roll of honour, but it could not be found.

[@CrackingTheCryptic]

It is actually a piece of music composed by Kurt Hugo Schneider, the KZbinr, who kindly offered it to us a couple of years ago :)

[@cruiseqe2]

@@CrackingTheCryptic Thank you for that.

[@GregJonson]

I solved this yesterday. I was baffled to discover the squiggly X-wing, I never saw anything like that. Quite clever.

[@holliambria9870]

That is lovely logic! I love the symmetry and it's so fun to watch everything come together.

[@Kirbyfan87827]

Finished in 23:29. I didn't think I'd be able to solve it, but then I had a breakthrough! I was shocked!

[@Sam_weiqi]

16:51 for me. Mark-style pencil marking helped me a lot :)

[@ExodaCrown]

I got stuck before at the beginning, so had to watch the video for a hint to were to look next. I didn't notice that r1c4 got forced up and the symmetry of the puzzle did something similar to the other end.

[@joubess]

This was a fun puzzle! Thank you Simon and Florian! It wasn't too hard to break into, and once you break in you can see where it's headed.

[@jasonveale8467]

This was quite a remarkable puzzle. The logic and the symmetry was just wonderful. Thank you, Florian!!

[@yaelvercammer5468]

Posting my time for others who would be intimidated by all the fast times in this comment section :D I made it in 54:43 Thank you Simon for sharing all these cool puzzles and occasionally including an approachable one! You're definitely one of my favourite people too :)

[@grahamrskelly6042]

Beautiful puzzle. 😊 And a lovely video, and congratulations to all the solvers on the roll of honor

[@emilywilliams3237]

I gave this puzzle a try before watching the video, and would have taken it all the way home by myself, except I wanted to have the pleasure of watching you solve it, Simon. Thanks so much - a beautiful puzzle and a lovely solve video.

[@ianrodd1423]

Best sudoku I have ever seen that I could do. 80 minutes of slow progress. Amazing construction all around

[@mega9tales]

13:50 for me, and that's not far off what I sometimes end up with on tougher GAS puzzles, so I definitely think this one fits the mark for approachability! Loved all the doubles, triples, and quadruples that the thermos present you with right from the start, really smooth solve and quite enjoyable

[@Coyotek4]

10:45 ... this one helps take the sting out of yesterday's failure (by me) Nice puzzle!

[@inspiringsand123]

Rules: 05:33 Let's Get Cracking: 06:15 What about this video's Top Tier Simarkisms?! Three In the Corner: 3x (23:27, 23:29, 23:32) Goodliffing: 1x (06:29) And how about this video's Simarkisms?! Symmetry: 9x (02:18, 02:20, 07:26, 09:38, 17:44, 17:51, 19:54, 20:23, 24:19) Obviously: 6x (04:38, 05:22, 08:25, 23:47, 26:04, 26:07) Pencil Mark/mark: 5x (06:38, 06:44, 06:48, 07:51, 08:56) Cake!: 5x (04:20, 04:41, 04:44, 05:01, 05:06) Beautiful: 4x (14:13, 15:34, 15:34, 25:49) Lovely: 3x (04:36, 04:53, 15:58) Corollary: 3x (08:47, 17:27, 18:20) In Fact: 3x (17:33, 17:49, 21:19) Ah: 3x (08:26, 13:35, 13:45) Sorry: 2x (09:08, 20:39) Gorgeous: 2x (26:13, 26:16) Our old Friend Sudoku: 1x (23:03) Come on Simon: 1x (10:12) Whoopsie: 1x (21:57) Phone is Buzzing: 1x (20:39) Wow: 1x (02:11) Losing my Army: 1x (08:22) Most popular number(>9) and digit this video: Ten (6 mentions) Five (49 mentions) Antithesis Battles: High (3) - Low (3) Higher (4) - Lower (1) Row (19) - Column (12) FAQ: Q1: You missed something! A1: That could very well be the case! Human speech can be hard to understand for computers like me! Point out the ones that I missed and maybe I'll learn! Q2: Can you do this for another channel? A2: I've been thinking about that and wrote some code to make that possible. Let me know which channel you think would be a good fit!

[@Tahgtahv]

Not sure what the magic phrase is for detecting the end of the solve. It was about 19:25 minutes today (end time 25:40). (Not sure if the extra long outro confused things either.)

[@nestoreleuteriopaivabendo5415]

Good bot!

[@65Superhawk]

20:58. I goodliffed and I am glad I did. Really easy with pencilmarks and a bit of color (for me to recognize the triples)

[@KestrelQ]

It's always a little sad when a puzzle takes me way longer than everybody else, sometimes I think I'm learning a lot about sudoku and then my brain just misses things and I watch some of the video for help :( Lovely puzzle, I just wish I was a bit better so I could solve it myself and enjoy the logic fully!

[@longwaytotipperary]

That’s ok - it’s still fun to sit back and let Simon do the heavy lifting (but not Goodliffing 😁)!

[@ashnikchauhan9103]

The logic I reached in about 30 min you crack in 15 min into the video thats including the intro. Even though by now I should be used to your cracking prowess, Simon you still amaze me everyday. Another good one by Florian Wortmann, it was genuinely approachable although on first look it seemed like a 3 star difficulty to me. Then Mr Goodliffing to rescue and things made more sense. Penciling things down helps me make more sense of it. Keep on cracking.

[@omarenm]

46:14 I feel proud.

[@bait6652]

Very nice coloring and dualsolve bifurc. And its nice to see diff ways to solve

[@tianyi05]

At about minute 10:30 columns 4 and 6 had sextets one low (123456) the other High (987654) which forced the other three digits into the columns. This allowed you to reduce the degrees of freedom in the top and bottom thermos much sooner.

[@cathybryant5119]

Yes I noticed this almost at the beginning of my solve and was sad that Simon didn't see it. It's interesting that he and I solved it fairly differently but got to the same place in the end. The mark of a wonderful puzzle!

[@Tepalus]

19:27 for me. Lovely start of the weekend! :)

[@DarrenNakamura]

Finished in 39:01. Great puzzle!

[@EldritchNerd98]

Depending on the phone, usually if you click the power button it will silence the call / stop it vibrating and if you do it again it will actually reject the call.

[@roirodriguez9688]

i loved the logic simon used regarding max digit in columns! my breakin was more like last column cannot contain 6 or 7 in box 6 over the thermo because if so we can't put them in box 9... I liked this puzzle, ~17' here

[@coltith7356]

Oh my god I am genuinely so happy, this is the first puzzle that I managed to solve on my own. Usually I need to watch the video because I can never find the first few digits and then sometimes even after that I get stuck and need to watch a bit more to get a new digit and keep going, but for this one I set myself the objective to do it alone even if it took me a month and 15 resets. Turns out I was able to do it in 88.5 minutes and with 0 mistakes. I know that for many people here this might sound like a lot, especially for an easy puzzle like that, but I'm just happy I did it and I am looking forward to repeating this success with another puzzle.

[@jonnybolton4659]

Lovely symmetry in this puzzle. We're very used to rotational symmetry where opposite digits add to 10, but this is the first time I've seen it in a thermo puzzle; it works because after rotating the thermos you then have to reverse them. Very cool

[@MarushiaDark316]

It's always entertaining when Simon is forced to fully-pencil-mark thermos.

[@Pathogenus]

the puzzle where goodliffing thermos is the way to go, perfect

[@KSilverlode]

This was deightful. I really enjoy thermos and this one was a lot of fun.

[@zielinsqa818]

You could choose a day in a week when you solve harder puzzles that result in longer videos.

[@sper1585]

It's interesting to see a different thought order of solving.

[@jensschmidt]

13:36 ... well... if only you saw the 24 pair and the 68 pair... but... you're Simon, so you don't... we love you. Never change!

[@jensschmidt]

Today was a exceptionally grand example of Simon ignoring Sudoku for totally complicated logic. From the first to the last second.

[@chris5619]

Not only did the pairs help there, but whichever outer cell was a 2 needed a 1 in the bulb, so the 4 would therefore only have a 3 left. Same for the tips.

[@piarittersporn]

Beautiful puzzle.

[@martinyyt]

Lovely, lovely, puzzle, that. Finished in 73:01. Took it slowly and it took me a while to discover how to disambiguate the two long thermos - which was the final step I needed in my solve.

[@SirFunkyton]

I had the same issue! I dislike thermo and arrow puzzles hahaha. My issue was I kept searching for triplets and quads when i should have been looking for pairs. I made it much more complicated than it needed be.

[@airwalkalman]

Symmetrical puzzles like this tickle me pink!

[@Poet13xRatedRKO]

Dude that was fantastic! I love thermos and this time I destroyed the puzzle, it felt like GAS. My time is 09:26. Seems like I saw everything important on the spot.

[@chris5619]

I agree on the GAS feeling, but I took bit longer at 14:14. I went full Goodliffe, and one thing I noticed immediately, was that due to the need for the 4-9 on one of the outer thermos, you could eliminate 4, 5, 6, 7, 8(&9) from the rest of columns 3, 4, 5, 6, and 7, respectively. This eliminated some of the other pencil marks on thermos and I think helped a little. Of course that worked the other way around, but I never even got to the point of thinking about that since everything just flowed so smoothly.

[@emilymiller4349]

Fun puzzle! Thank you. Took me 54 minutes. I like this difficulty level--challenging and enjoyable, but solvable for the "advanced beginner."

[@Tker1970]

Fun puzzle! I don't mind the long puzzles. They are very interesting. What makes my wander are the super complex rule sets. I can't keep up with those-sometimes I can't understand them.

[@Squishy3757]

Fascinating insight into Simon’s mind.

[@windybeach2184]

6:28 as someone without much of a mind’s eye, I tend to Goodliffe all the cells to help visualise patterns. But I agree with Simon that they can blur the most useful information. I like to solve the puzzle alongside the video, so I can clutter my own grid while also enjoying to Simon’s tidier clues. I love how different brains work!

[@alanclarke4646]

"this square's got to be a something!" 😂😂😂

[@MisterM2402]

19:41 for me, not far off Simon's time. I find it much easier filling in thermos completely and then looking for patterns. Simon's method of visualising thermos in his head seems too fiddly for me.

[@goleyeath]

It's always pleasing when such a neat looking grid solves so smoothly. I'm not too proud to admit that I Goodliffed this one into submission. Fun puzzle!

[@longwaytotipperary]

I’m a proud Goodliffer on most occasions!

[@adamheywood113]

About 30 mins to solve, happy with that because I was pretty stuck in the middle Haven't watched the video yet so I don't know if you had the same solve path but I noticed a sort-of virtual x-wing with 9s in the top and 1s in the bottom I was able to remove 9 from R2C2 and 1 from R8C8, and that resolved to an x-wing on 5s in the corners of the Phisto square Beautiful puzzle, thank you for featuring

[@cathybryant5119]

I used that info as well. I love how there are several paths through this puzzle.

[@ericsjoberg8167]

This was great!

[@JohnRandomness105]

Somehow, I managed to break the puzzle the first time around. But I managed it the second time. The puzzle has an exact symmetry: flip across the center (or 180-degree rotation) and N ==> 10 - N. Mark would instantly pencil in the two long thermos, and I suggest you do it too. 8:50 The restrictions on 4 and 6 in rows 3 and 7 lead to interesting results. 10:10 Also faucets and hinged door handles. 13:20 The middles can be removed from the bulbs and ends as well. Short-cut: use the 68 and 24 pairs. 21:20 Another way is to fill out the left thermo.

[@BlueCyann]

16:50 i think 1 star is underestimating it -- it's not GAS level of difficulty. Really fun to solve.

[@samgillmusic]

Loved the level of this one, challenging but each step was identifiable for me. I got it in 38:19

[@eleanorshuttleworth9346]

40:13 for me, it took me a long time to see the sextuples in column 4 & 6. Honestly the first puzzle I've solved that I can describe as gorgeous!

[@Issaquatch]

Beautiful puzzle. Fun and consistent in difficulty (not too difficult but not GAS) from start to end. 26:07 for me.

[@jonhansen9622]

Looks like we should try this before watching the video!

[@minorasimulator]

This puzzle has got some stunning logic, my partner now thinks I'm mad!

[@tubebrocoli]

Really cool antisymmetric puzzle! It's really interesting how it uses the thermos to make it solvable by having the antisymmetry everywhere except for the 5s

[@peaoui165]

On most modern phones, to reject a call if your screen if locked, you puch the screen lock button. If the screen is unlocked there should be a "reject call" button visible

[@Xiuhtec]

33 minutes for me, very fun smooth solve!

[@spooony2714]

Nice puzzle, pretty easy but with a really good flow.

[@Xzyzygy]

Lovely puzzle - 24:38 for me, without recourse to Simon's leading hand. Pretty pleased with that.

[@karlmortenlunna2417]

Very nice puzzle. Fun and easy. 07:46 for me today.

[@LarkyLuna]

Oh, I did that one yesterday in LMD Very good puzzle

[@specialkalberta]

I did some of the things Simon did but got stuck and have to question the 1 star for difficulty rating.

[@minorasimulator]

I think I would definitely bump it up for difficulty, but only because it took me a while to get to the break-in

[@ymiros0953]

Yeah I also don't think 1 star is justified. Maybe if you're pretty experienced with thermo sudokus

[@Tony_Regime]

I'm very happy with 25:11 and a little surprised I solved it that fast. great puzzle

[@crabs17]

14:59. love a good thermo (almost felt like a GAS)

[@Mn0ty]

12:29 That was fast🤣

[@kgeiger61]

Thermo puzzles are some of my favorite. 25:28 for me.

[@jaredgudnason4400]

harder break in than i expected based on the video length, but nice puzzle overall, and very satisfying to solve. Thanks! (27 min)

[@benjaminrealy5661]

18:59. Yay. Been doing excellent all week. Probably jinxed myself. Lol

[@sanctionbuster]

26:03. Skadoosh!

[@bkaozzz]

9:19 for me, pencil-marking everything made me visualize everything a lot easier!

[@josephblack2757]

Anyone know what the music is for the Roll of Honor? It's lovely.

[@titusadduxas]

33:28 for me, though I did take a (correct) guess on which thermo was the low one - I couldn’t spot the disambiguater.

[@skid68]

When you Simon said all is 10 I started to see that on every place in the whole puzzle, felt like cheating :)

[@richardtreat4158]

So after Marking up the outer thermos, and seeing how they restricted the inner thermos, I then found a trick with set theory. Comparing boxes 1,3,6 & 9 with row 3 & 7 and column 1 & 9, and after subtracting the duplicate cells you end up with one set of digits lying on the thermos on column 1&9 plus the thermos in row 3&7 (but importantly, excluding the bulbs/tips of any of those thermos!); and the second set being 2x2 boxes in boxes 1,3,6 & 9. The second set contains the end of the small Thermo in box 1 and the beginning of the small Thermo in box 9. Which means that the Thermo in box 1 can’t contain a 9 and the Thermo in box 9 can’t contain a 1!! This ends up forcing a 5 on to r1c4 and a 5 on r9c6, once you look at how the thermos in boxes 2,5 & 7 interact. I was excited to watch Simon’s solve fully expecting to hear about blue bags and purple bags, but surprised to find out that set theory was not required to solve the puzzle. I feel like I over complicated it, but I’m still kind of proud on finding that trick!

[@DWestheim]

19:43 with the Goodliffe Method, although I didn't fill in *all* the candidates right away, because the quadruples in rows 3+7 let you eliminate some things immediately.

[@williammorris7279]

This is a "once in a blue moon" day for me, and I am feeling absurdly proud, given that I needed help to get to that point! At 19.46, I spotted that those digits needn't be 5 and 5, but could be 4 and 6, which obviously also add up to 10, and turned out to be the case.

[@veggiet2009]

I got the marking done on the big thermos mostly correct like you did, but then i got stuck, then i watched the video and where i got lost by Simon's logic is the 9 in row 3, and why 9 could only be there and not in the other blank space

[@KrisCadwell]

Fun puzzle

[@Stephen-Fox]

12:42 time for me. Once you find the break in this goes remarkably fast.

Wonderful puzzle! Similar break of symmetry as last Sunday's late edition puzzle. "Note to the cognoscenti": The digits in the corners of box/block 5 is the digits that can be the last digits of square numbers. That is NOT 2,3,7,8.

[@mudscuffer]

That went really smooth - 13:31 for me