Tiramisu: made with raw eggs
Steve's recipe

Tiramisu has for a long time been one of my favourite desserts. But it was only recently that I got around to making it for myself. When I searched for a suitable recipe that would satisfy a tiramisu connoisseur like me, I was surprised to find a huge number of very different recipes. Many so-called 'tiramisu' desserts bore little resemblance to the classic Italian delicacy.

Tiramisu is basically an Italian trifle. The essential ingredients are boudoir biscuits, mascarpone and eggs. Apparently, it was originally designed for children but, with the addition of coffee and alcohol, it has become a popular adult dessert. The basic recipe uses raw eggs. One of the reasons why there are so many different variants is that people try to find an alternative to the raw eggs.

Eating Raw Eggs

Some people are afraid of eating raw eggs because of the risk of salmonella poisoning. That's fair enough because many official and unofficial sources advise against eating raw and lightly-cooked eggs. But how risky is it? Many recipes tell you to warm the eggs to kill off any salmonella, but these bugs don't kill that easily. Unless you heat them enough to have scrambled eggs in your tiramisu, you are likely to help any salmonella to grow by warming it up.

The risk of salmonella in eggs first became a problem in the 1980s. Since then, a huge amount of study and regulation has taken place. An egg gets infected with salmonella by being laid by an infected hen. Today, all fresh eggs sold in the EU must be certified to be from healthy flocks, free from salmonella infection. In Switzerland (where my eggs come from) and some EU countries, they go further than the EU regulations: infected flocks have to be slaughtered. And the Swiss are very good at rules!

Risk Assessment

After all the trouble and expense that has been incurred to ensure a healthy supply of fresh eggs, it does seem crazy to behave as if we had never done so. Why would we continue to avoid raw eggs if the problem has been solved? Of course, there is still some risk. However, as is always the case with very low levels of risk, it is difficult to obtain reliable figures. The UK Food Standards Agency did a study in 2004, in which they tested some 28,000 eggs on sale in shops. They found contamination on a few of the shells but no salmonella inside any of the eggs. The US Department of Agriculture did a theoretical study in 2002, which estimated salmonella contamination in eggs as 1 in 20,000.

Let's do the calculation with the 1 in 20,000 figure. That's probably a worst case, at least in Europe. Suppose I eat 10 raw eggs a year. Then, as a rough estimate, my chance of eating salmonella this way would be 1 in 2,000 per year. Therefore, the probability of getting salmonella poisoning from raw eggs over my lifetime of 100 years (using the handy Cool Risk calculator) is about 5%. Seems like a reasonable risk to me.

Anyway, I like tiramisu!

Steve's tiramisu recipe