Saturday, April 21, 2018


Unlocking the next Locks and Libations pairing in this series brings us to perhaps the most celebrated of all puzzle locks, the DanLock.  Most agree that this incredible classic deserves a spot as one of the all time greats in the puzzle “Hall of Fame” and certainly the puzzle lock Hall of Fame.  Much has been written about it and the nuances are likely familiar to most.  The puzzle was originally crafted by Dan Feldman out of a solid brass Nabob padlock from the premier Israeli lock company, founded in 1945 by Israel Barzilai.  The Israelis certainly know a thing or two about security.  

DanLock by Dan Feldman

Dan worked at IBM for 37 years and had a degree in mathematics and statistics from Tel Aviv University. He was fascinated with mechanical puzzles from his childhood when he built his first puzzle, the Chinese Rings, from instructions in a magazine.  In the early nineties he began collecting locks and puzzle locks, and developing his own ideas.  In his search for a factory to produce his ideas, he met Israel Barzilai of the Nabob company.  The friendship, and Israel’s extensive knowledge of lock mechanisms, led to the creation and production of Dan’s early lock puzzle inventions, the “Trip”, “Multip”, “Temptation”, and “Locked & Broken”.  It’s wonderful to know that Dan’s most famous puzzle, the “DanLock”, which provides a number of independent AHA moments, was itself born out of an AHA moment which Dan had while thinking about his prior lock puzzles.  The DanLock “B” was created years later, with changes to the inner mechanism and an added challenge.  In this version, four different tricks are layered sequentially to create the infamous puzzle, which starts with one key to the lock firmly secured to the shackle and another one broken in half.  The puzzle has likely become so admired over the years due to this very beginning, which invites the unthinkable, challenging the solver to avoid doing something uncomfortable or disastrous.  Add to that some incredibly tricky additional steps to put things back the way they started (which most also agree is the real puzzle) and it’s not hard to understand why this is such a classic. 

The Incredible Dan Feldman (IDF?)

The tradition of the DanLock continues with Dan’s son, Boaz, who now produces these locks with a steel shackle and a nice logo with the continued assistance of Israel Barzilai from Nabob.  Boaz shared some stories from the early days of the DanLock, which was originally released before widespread use of the internet.  People heard about it via word of mouth, and obtained a copy after exchanges of letters.  When they received the package after much waiting, they got a … broken key! What?! They wanted to ask about it, but couldn’t.  Many assumed it was a joke, or a mistake.  To this day it’s amazing see how different people approach this problem, with every imaginable permutation of action or inaction, which hasn’t changed since the first DanLock was released.  It’s also funny to watch people eventually succeed triumphantly with the second step, only to quickly realize they are completely stuck again in the ultimate paradox.  Some people even claimed the lock to be a scam.  Boaz’s fondest recollection is from an article by Edward Hordern in which he praises the DanLock: “If I had to give away my entire collection of locks – there must be a hundred or two hundred of them – and keep only three, this recent acquisition would be one of them. As the other two are rather nice antique ones."

Stop and Go by Julia Momose

At each step in the solving process for the DanLock, most people are stuck for a while (sometimes a very long while), have an epiphany, go forward a bit, and have to stop again.  This process repeats itself a few times before victory is at hand.  I found the perfect unlocked cocktail to pair with this puckish padlock, the aptly named “Stop and Go” by mixologist Julia Momose.  She created it as part of her “zero-proof” (non-alcoholic) pairing menu for Chicago’s double-Michelin-starred restaurant Oriole.  Her goal with these zero-proof cocktails was to show people how elegant and complex these drinks can be, crafted with the same care and culinary intensity typically reserved for high proof cocktails.  

No alcohol is nothing to wine about ...

The drink features Verjus, the pressed juice from unripe grapes, which translates from the French literally as “green juice”.  It is high in acidity and low in sugar, and it remains unfermented, so is non-alcoholic.  Reminiscent of wine, and much milder than vinegar, it is often used in sauces and mustards, and more recently, cocktails.  It shines in the Stop and Go, which uses rich demerara to sweeten the elixir and tonic to give things a festive pop.  The name derives from the color of the drink contrasted with a vibrant sage leaf floated on top.  Try this unlocked cocktail while trying your hand at unlocking the DanLock – it will keep your mind clear, even if it remains the only solution you find.  Cheers!

Stop and Go get yourself the incredible DanLock

Stop and Go by Julia Momose
2 oz Verjus rouge
1 oz rich demerara syrup
Tonic water to taste
1 sage leaf

The tradition continues with the new DanLock, produced by Boaz Feldman

N.B.: Special thanks to Boaz Feldman for the wonderful history and stories he provided.
The new DanLock can be ordered by contacting Dan Feldman’s daughter at:

For more Locks and Libations see:


  1. Lovely review Steve. The Dan (and now his son Boaz) lock is absolutely one of the best. A pleasure to read another review, with another perspective. Brilliant:-)

  2. Thanks Shane. Glad I could contribute a new perspective on this beloved classic.