Pavlovas: mix in or fold in the vinegar or lemon juice?
Normally, the acid helps the whipped eggs whites hold their structure and is mixed in when the whites are still liquid.
In Pavlovas, many recipes state to fold in the acid AFTER the whites have been beaten to the stiff peak stage. JoyOfBaking.com says the acid helps create the marshmallow like texture inside the meringue cake.
I tried a Pavlova with the acid mixed in at the beginning like I usually do and got a marshmallow texture to the cake anyway.
Does it matter if the acid is mixed in at the start or folded in after the stiff peaks? If folded in, the acid won't be as evenly distributed.
Easier, faster and better disbursement when mixing the acid in at the beginning, imo, before whipping rather than after. I've never folded it in during whipping, either, along with the sugar and flavoring, so I can't say without a doubt which technique gives a better result, but I have certainly been happy with my results. I add in the cornstarch towards the end of whipping. Use the beater from your mixer to fold the starch in, rather than a spatula.
I have seen recipes that don't call for an acid at all, just egg whites and sugar, but the original recipe developed by Pavlova creator pastry chef Herbert Sachse, did.
Try folding it in during or after whipping, report back if there's a noticeable difference in texture.