Week 4: Lemon Curd

 Last week we explored the difference between yolks and whole eggs in lemon curd. The lemon curd recipes I found in my research span a wide range of possible ingredient combinations, so this week I wanted to find a base recipe to work with before I dive into tuning anything. 

Table 1: Several recipes for lemon curd in percent from [1], [2], [3], [4], [5], [6], [7]. Note that these are rounded to the nearest tenth of a percent, so the total values may not add up to a perfect 100% due to rounding error.

Looking at the recipes above, I picked four that span the range of typical recipes (that are not in the penalty box): 

Table 2: Four recipes for lemon curd in percent from [1], [2], [4], and [7]. Salt and lemon zest amounts are not included in the table, but were included in the recipes when made.

Split H had a very strong, tart lemon flavor, but it dissipated quickly in the mouth and was not silky at all. It seemed more like lemon jam than a curd. Its thickness reminded me of warm brie. It could hold its structure a bit, but it was not thick. Split I held its shape without falling and was silky and smooth in texture. Both the lemon flavor an the tartness came through much better in Split I than in Split H. Split J was very stiff and was a bit gritty with a texture much closer to that of butter. It had some tartness, but it lacked a strong lemon flavor. Split K was a bit goopy in texture and had a sticky mouthfeel. It had even less lemon flavor than Split J and was sweet with no tartness at all.

From the top left corner going clockwise: Split H, Split I, Split K, Split J.

Split K was the last of the lower lemon juice more sugar group in Table 1 (Recipes 4-6), so I think this rules out this whole class of lemon curds. Split J (Recipe 7) was between the lower lemon juice more sugar (Recipes 4-6) and the more lemon juice lower sugar groups (Recipes 1-3) and still fell flat, so I think my ideal lemon curd is firmly in the more lemon juice lower sugar group of recipes. This will set some bounds on how far I take variations on these recipes in future weeks.

Split I (Recipe 2) was the winner by far in the splits that I tried this week. I also really enjoyed Recipe 3 last week with some whole egg substituted in for some of the yolk. If we look at these recipes side by side, we can see that they are actually incredibly similar. They both have roughly the same amount of butter  (~20.5%), and they use similar total amounts of egg (Recipe 2 ~21.7%, Recipe 3 ~24.9%). If we look at the lemon juice and sugar amounts and take what we learned last week about whole eggs vs. egg yolks, these recipes begin to make a bit more sense. Recipe 2 uses some whole egg versus only yolks as in Recipe 3. This means that the lemon flavor for the same amount of lemon juice will be brighter, so it makes sense that Recipe 2 uses less lemon juice and more sugar compared to Recipe 3 where the yolks dampen the tartness and lemon flavor.

Split I is my favorite recipe from the bunch, so I will make this my reference. Next week, I will play with different whole egg to egg yolk ratios to find my ideal balance of brightness vs. velvety texture.