In Dave Arnold’s ‘Liquid Intelligence’, he talks about about a method he uses to increase the acidity of orange juice to make it act as a substitute for lemon or lime as the sour component in a cocktail. This got me thinking about other juices that might be suitable for the same treatment. Pineapple juice seemed like a likely candidate, as it’s got some acidity already, and conveniently pineapples have just gone on sale here.
I did some research on the acid content of pineapple juice, wading through various industrial science papers from the pineapple industry, and, as best as I can determine, pineapple juice has an acid content of about 1.2 g/100ml, of which 87% is citric acid and 13% is malic acid (the same acids as in lime juice, just in different proportions).
I picked up a small pineapple, peeled and cored it, and threw it in a blender. Then I strained it and squeezed it through a nut-milk bag to get rid of as much pulp as possible. My final yield was 400 ml of juice. I knew I wanted a final acid content of 6 g/100ml, so I needed to add 4.8 grams of acid per 100 ml, or 19.2 grams acid total for the 400 ml. I went with a mix of 15.6 g citric acid and 3.6 g malic acid (about 4:1, part way between the acidic composition of lime juice and that of pineapple juice). Then I stirred until dissolved.
Based on the combination of acids, I figured the taste would work best as a substitute for lime. I substituted the juice for lime juice in a gimlet and in a daiquiri, and both were spectacular. A couple nights later, at the local cocktail book club meeting (where we were, not coincidentally, discussing ‘Liquid Intelligence’) we tried it in a Last Word. Aside from being a bit to sweet (the pineapple juice has about 8 times the sugar as lime juice), this was also quite good. The only recipe I’ve found it to be an unsatisfying substitute for lime juice is a margarita.
Next time I’m going to try getting the acid ratio a little closer to the 7:1 ratio of pineapple juice (so 4.2 g citric and 0.6 g malic per 100ml) to see how that affects the flavor. My guess is that this will make it a better candidate for replacing lemon than lime.
Lime Strength Pineapple Juice
Peel and core a pineapple. Blend and strain, or run through a juicer. For every 100 ml of juice extracted add:
3.9 g citric acid
0.9 g malic acid
Stir until dissolved. Refrigerate, keeps at least a week, but the flavour is best right away. Use in place of lime in any recipe, but reduce the amount of simple syrup or liqueur or it will be a bit too sweet.
60 ml gin
25 ml lime strength pineapple juice
20 ml simple syrup
Shake with ice. Strain into a cocktail glass.