SPOILER ALERT: Reading this section could seriously put you off your cream tea!
It’s perhaps worth describing some strange little bits of food chemistry at this point, for some unusual but potentially off-putting encounters:
Firstly, lactic acid can curdle cream on contact – something which may happen if you are using partially fermented jam (usually without realising it) and wonder what the cheesy taste is. Check your jam for tiny bubbles or froth and the taste and smell of fermenting fruit, before thinking your cream is off.
Secondly, natural citric acid in tangy jam can curdle cream, releasing an unpleasant sour milk odour and taste. This is easier when the cream is light or hot. Normally, the microscopic make-up of a stiff cream is more resistant to the effects of acid, and additionally, a thick layer will insulate a warm scone from even an acidic jam and you won’t have a problem. But a light cream (or a thin smear of cream) on a hot enough scone can momentarily cause the right conditions for an acidic jam to come in contact with hot cream and partially curdle it before things cool down. If your cream is thinly spread, the scone hot, and your jam sharp, don’t blame the shop if you experience this sourness.
Thirdly, biological enzymes (lipases) from bacteria which get into the cream will gradually break down the triglyceride fats (lipids) in the cream, releasing increasingly obvious amounts of a smelly chemical (in many cheeses) called butyric acid. This may be suddenly supplemented by acidic curdling processes (above) to push the cream’s bad smell and taste from below your nose and tongue’s threshold, to above it.
(MOUSTACHE ADVISORY: Fourthly, the huge surface area of a moustache means that a huge number of skin bacteria may already have huge amounts of lipases stored and ready to pounce on any unwary cream intrusion, causing a very quick release of butyric acid literally under your nose, without having to wait for any bacterial growth.)
© Ditch Townsend and Devon Cream Teas, 2015. Unauthorized use and/or duplication of this material (including but not limited to the text and images) without express and written permission from this blog’s author is strictly prohibited. Text excerpts (but not images) and links may be used, provided that full and clear credit is given to Ditch Townsend and Devon Cream Teas with appropriate and specific direction to the original content.