The Most Extraordinary Lemon Tart Re-thunk

A few weeks ago, I posted the recipe for this lemon tart, a favorite of mine from Pierre Herme, on Serious Eats and, coincidentally, it was chosen as the recipe of the week by the wonderful bakers at Tuesdays with Dorie.  I heard from some of you that you were having difficulties getting the lemon cream up to 180 degrees F -- 165 degrees F seemed to be the stopping point -- and that whether you called it quits at 165 or kept going to 180, it was taking a long time and a lot of elbow grease to thicken the cream.

Well, I made the recipe over the weekend and I've got a new thought on how to speed up the process and still get the thick, smooth, almost velvety cream that makes this tart so remarkable.

To recap, the recipe calls for the sugar, lemon zest, lemon juice and eggs to be mixed together in a bowl.  The bowl is put over a saucepan with a few inches of boiling water and you whisk, whisk, whisk until the mixture thickens enough for the whisk to leave tracks, then you keep whisking until the cream measures 180 degrees F on a candy or instant-read thermometer.  To finish the cream, you pour it into a blender and cool it slightly before you whir in room-temperature butter -- but that's not the problemmatic part.

So here's what I did over the weekend -- I got bold!  To make my double boiler, I used a soup pot and I filled it about 2/3 full of water, which I brought to a boil.  I then put the bowl (a metal bowl) with all the ingredients over the steaming soup pot (making sure that the bottom of the bowl wasn't touching the boiling water) and whisked like mad.  With so much heat under the bowl, the cream came up to 180 degrees F in under 10 minutes (in fact, the first time I did it, it took 4 minutes and 39 seconds; the second time, it took almost 7 minutes -- different bowl, different pot, different stove).

Of course, if you're going to supercharge the power under the bowl, you've got to be vigilant -- you can't take your eyes off the cream; energetic -- you can't stop whisking, even for a few seconds; and  nimble -- as soon as the cream shows the slightest signs of thickening, measure the temperature and make sure to remove the bowl from the heat immediately the instant you hit 180 degrees F.

A couple of other re-thinks:  If your lemon zest was very finely grated (I use a Microplane grater/zester), then you don't need to strain the cream -- just quickly scrape the hot cream from the bowl into the blender.  And, while you shouldn't add the butter to the cream while it's still very hot (if you do, then the butter will melt, as it does in a lemon curd, and you won't get the great texture that sets this cream apart), you don't really need to measure the cream's temperature before you butterize it -- if you leave the cream in the blender for 8 to 10 minutes, it will be just the right temperature for blending in the butter.

Finally, I made this tart on Sunday as part of my workshop at Pastry Scoop's Spring Conference at The French Culinary Institute, and, because it was at hand, I used lime juice in place of the lemon juice and it worked perfectly.

I hope those of you who haven't already made the tart, will -- it's really one of my all-time favorite recipes -- and that those of you who've already made it, will find these tweaks helpful the next time you decide to whisk up this treat.

Comments

[Bronwyn Carlisle]

I have been thinking since I first read this that it sounds like sweet lemony hollandaise sauce! How delicious can you get? Haven't made it yet, but I will.

[Paula]

Hi Dorie,
This recipe is absolutely wonderful and a favorite of mine. When in Paris, I always get a lemon tart at Pierre Herme. Can you share the secret of the little bit of fresh lemon he puts in his tarts? It tastes like it might be lightly candied.

[Kelly Fink]

Dorie,

it did turn out perfectly! I was one of the student helpers at your demo at the Pastry Scoop conference. It was truly a pleasure to meet and work with you! Thank you again for coming for the day and for rolling through a few equipment snags with grace :)

Kelly

[Sheltie Girl]

Thank you for tackling raising the temperature issue. Your alternate method makes short work of raising the temperature. Thanks for sharing it with us.

Natalie @ Gluten a Go Go

[Lauren]

Dorie,

This tart really is extraordinary, when I made mine (orange flavor), I did not use the double boiler method, I kept whisking and moving the pot off and on the heat. Once again, thanks for your guidance.

[Judy]

Hi Dorie,
Thanks for the update. This is one of my favorite desserts. I was one of the few who did not have problems with the temperature, so I'm sure your suggestions will help the others. A lime version is next on my list, and when my blood oranges are ready, I'll try that as well.

[Lindsey (Cafe Johnsonia)]

Thanks, Dorie! This will be immensely helpful the next time I make that recipe. You are the best!

[Tammy]

Wow, I had just earmarked that recipe to make. Guess it's settled now. Double-boiler, here I come.

[Sarah]

I found it. I made the french yogurt cake. There's even a spot on the page as proof positive. :)

[Sarah]

Hi Dorie! I hope you can jog my memory. Last year for Mother's Day I made the lemon cream and used it as filling in a cake. I cannot find or remember where I got the recipe for the cake. I've checked the archives on this site and I've read and re-read Baking but I'm not finding it. I'm going to google it. Maybe it came from a visit you made to some show or NPR. I hope you can help me remember what I'm looking for. (I know. My memory is just pathetic)

[Maria]

Dorie-Thanks so much for the additional tips. We are making lemon cream tarts for my wedding soon and the extra advice will come in handy! We have made the tarts several times and they are always delicious! I will have to try the new techniques next time! I can't wait!! I know the guests will be in heaven. You can't go wrong with a Dorie dessert and we are having several!

[Alanna]

Dorie ~ Is it any wonder that you have so many fans among food bloggers? It's not just the recipes, it's this kind of grace. What other cookbook author ends up with hundreds of public recipe testers? With your response, you show us how best to respond when readers have experiences we hadn't anticipated.

PS I appreciated the distinction of what makes this filling different from lemon curd because I didn't get that difference, quickly scanning the recipe.

[Jan]

this really is one of the best recipes in the dessert/pastry world. last weekend i hosted a baby shower and made two bite tarts with a raspberry on top. they were heaven on earth. this weekend for M Day -- Im going to try mini pavlovas with the cream and carmelized lemons on top.

Thanks Dorie for all efforts -- you really do make the world a better place. Thanks for caring about the home bakers out there.

[Madam Chow]

Dorie, I'd like to thank you for the update! I made the tart, to rave reviews, and had no problem getting the creme up to temp under your old system.

[kim]

Thanks, Dorie! It was so nice of you to come up with these tips. I joined TWD after they made this recipe, but I am definitely going to make it soon. Sounds delicious!

[Dana McCauley]

What a stunning looking dessert!

My mom loves lemony desserts. I think I'll make this for Mother's Day.

Thanks for the tips.

And, in the spirit of sharing, here's one of mine - if your arm flags while whisking, use your electric hand mixer instead.

[Carrie]

I made the tart as a member of TWD and did not have any problems with the cream reaching temperature.
I definitely plan on making this again and really appreciate your re-thunk comments/suggestions!
I'll be sure to implement them on my next lemon tart making adventure!

[Susan]

I made this myself a few weeks ago and also had trouble getting it to the 180. However, even after giving up around 170, it still turned out fantastic. It thickened just fine, so that wasn't an issue at all.

I'll try your suggestions from this blog entry next time. It will be interesting to see if it turns out different from last time.