I've have once succesfully made this Gordon Ramsay's Lemon Posset, but on the last two tries attempts I've not managed to thicken it.

After it has bubbled and kept bubbling for approx. 3 mins, I pour in the lemon juice while stirring, but the substance just doesn't thicken.

What are the most likely things I'm doing wrong? Not stirring strongly enough? Overboiling or underboiling? It did work fine the frist time (sigh)...

  • Doesn't thicken after many hours in the fridge, which is as cold as it was the other time you made it? I know it's supposed to thicken some right away, but that could help tell you how big your problem is. Are the lemons the same variety - and are they as acidic as the previous time? (I've made something almost identical twice with no problems - interesting question!) – Cascabel Jan 5 '12 at 20:19
  • Nope, it doesn't thicken even after being in the fridge (that had the same settings and I assume same temperature). It doesn't actually seem to thicken at all when I add the lemon juice, or if it does it's barely noticable. It is possible there is a difference in the lemons, I hadn't taken account of that. Is there any way to test, or add to the acidity? – Ilari Kajaste Jan 5 '12 at 20:25
  • Short of pH measurement, you can just taste them - we can certainly taste acidity, though it can also be covered up by sweetness. Hard to compare without tasting your original lemons, but if these don't seem very tart, that'd be a sign. (Most supermarket lemons are of reasonably high acid varieties - you haven't been using meyer lemons, have you?) – Cascabel Jan 5 '12 at 20:33
  • Regular supermarket lemons - don't think they were meyer lemons (which I hadn't in fact ever heard of before :) ). Though they might've indeed been a bit on the softer side as regards to acidity. Would adding more lemon juice compensate in such a case, even though it adds more liquid to the mix as well? – Ilari Kajaste Jan 5 '12 at 20:47
  • You could try using concentrated lemon juice. The coagulation process increases in proportion to the acid level, so a stronger acid will boost it. – ElendilTheTall Jan 5 '12 at 21:09

It sounds like your problem is most likely lack of acid. The acid is what causes possets to thicken. That could happen because the lemons aren't acidic enough (maybe the ones you had the first time were more sour). Re-reading your recipe, I notice that there's a second, simpler potential cause: your recipe simply asks for the juice of 1-2 lemons, and you might just have smaller lemons, or drier ones without as much juice.

For comparison, I've successfully made this lime and lemon posset, which uses 5 tablespoons of lemon and lime juice for 2.25 cups of cream. That'd scale to 42 mL of lemon/lime juice for your recipe. If you think you simply didn't have as much juice as before, or that the volume was less than that, I'd start by simply using more lemon juice.

If that's not the problem, and your lemons are for some reason less acidic, then the main option is still to use more lemon juice. Ideally you'd concentrate it, though, so that you don't end up with a smaller fraction of cream in the recipe. You can juice more lemons, then reduce the juice on the stove down to the original volume. (An easier option would be to add extra citric acid to your lemon juice, if you happen to have it.)

(Much of this was said in the comments, but I went ahead and made it an answer - please don't accept it unless you verify it though!)


I don't think the issue HAS to be acid. Cream comes in a variety of grades, and some contains far more water than others.

If you used a different kind of cream, like one that doesn't have a thicker layer of fat at the top, maybe try boiling a little longer to concentrate the fat and make more of the casein proteins available.


I would say the lemons are too ripe. It is the same with fruit And citris. You make your Jam and Marmalade when fruit is a little under ripe. My last lemon posset wasn't set right through . I noticed my lemons were a little soft. So maybe a little more lemon and reduce it a little before adding to the cream and sugar. My Grandson said Lemon Posset was the best dessert he had tasted better than anything he had had in a restaurant.


Let the cream cool to about 50,then add your lemons.

  • 4
    Cool to 50 what? And why? – Aaronut Dec 3 '14 at 10:36

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.