Running a bakery through a summer Christmas

Most cake writing comes from the northern hemisphere, where the busiest week of the year is also the coldest. In Australia and New Zealand it is the opposite, and most received wisdom about Christmas baking inverts with it.

Your peak, your wedding season and your worst working conditions arrive in the same fortnight. That is the whole problem, and it is solvable, but not by doing December the way a northern hemisphere bakery does it.

The temperatures that decide what you can make

Three numbers do most of the work here.

Cocoa butter melts at roughly 34 to 36 C (93 to 97 F), but tempered chocolate starts losing its snap and its surface well before that, from around 30 C (86 F). A chocolate sail, shard or drip that was perfect in the kitchen is soft by the time it reaches a marquee.

Butter has no single melting point. It is a mixture of fats that softens across a range, which is why buttercream does not fail suddenly, it fails gradually and then all at once. A buttercream that is firm at 18 C (64 F) is already a slump risk somewhere around 26 to 28 C (79 to 82 F), which is an ordinary December afternoon across most of both countries.

Fondant is heat stable and moisture unstable. It will happily sit at 30 C (86 F). What destroys it is condensation, which is why the fridge is not the free fix it looks like. More on that below.

Those three thresholds are the fixed part. The forecast is the variable, and it varies enormously across two countries that reach from the tropics to the Southern Ocean: a December afternoon in Hobart and a December afternoon in Darwin are not the same working day. Before you commit to a design or to a delivery time, pull the outlook for the actual date and the actual location from the Bureau of Meteorology or MetService and hold it against the numbers above, rather than against how the kitchen happens to feel that morning.

Ganache holds where buttercream does not

Ganache under fondant is already the standard finish across much of Australia, and in a summer Christmas it is also the correct one. It gives a sharper edge and it holds structure at temperatures where a butter icing is going soft.

The ratios that matter are chocolate to cream by weight, and they change with the chocolate:

• Dark ganache for covering work is commonly made at 2:1, two parts chocolate to one part cream.
• White and milk chocolate carry more milk solids and less cocoa butter, so they need more chocolate to reach the same firmness. 3:1 is the usual starting point, and 4:1 is the common answer for white chocolate in genuinely hot conditions.

Those ratios are tracking cocoa butter, not chocolate type, so two white chocolates at different percentages will not set the same way at the same ratio. Read the percentage on the block before you assume a ratio carries over from the one you used last time. And if you move to a firmer ratio for December and January, record it as a summer recipe with the months written on it, so it does not follow you into June and give you a covering nobody can get a knife through.

On buttercream, be honest about the trade-off. A meringue-based buttercream, Swiss or Italian, is mostly butter and behaves mostly like butter. An icing-sugar-heavy American buttercream has more sugar structure and holds marginally better. Replacing part of the butter with a high-ratio vegetable shortening raises the temperature it survives and changes the flavour and the mouthfeel, and there is no version of that trade where you get both. Decide which you are optimising for on each job, and do not pretend the substitute tastes the same.

The fridge creates a second problem

Chilling a cake for structure is right. Taking that chilled cake into a warm, humid room and unboxing it is the single most common way an Australian summer cake is ruined between the kitchen and the table.

Any surface colder than the dew point of the air around it collects water. A cake at fridge temperature carried into a 28 C (82 F) room at high humidity sweats immediately. On fondant that means a tacky surface, colours bleeding, dusts and lustres streaking and sugar work going soft.

The rule is: the box is the buffer. Chill for structure, transport cold and let the cake come up to temperature inside its closed box before anyone opens it. The condensation forms on the outside of the box instead of on the cake. A large cake takes hours to come up, not minutes, so this has to be in the schedule rather than remembered at the venue.

Transport is where most of the damage happens

The car is the hottest place the cake will ever be, and a parked car in an Australian or New Zealand summer gets far hotter inside than the air outside.

• Never the boot. It is unventilated, uncooled and you cannot see what is happening. This is not a preference, it is the difference between delivering a cake and delivering a decision about a refund.
• Cool the car before loading. Run the air conditioning with the doors shut for ten minutes so you are not putting a cold cake into a hot cabin.
• Cake on the flattest, lowest surface, usually the floor behind a front seat, on a non-slip mat.
• Aim the vents so cold air circulates in the cabin but does not blast directly onto one side of the box. Directional cold is its own kind of damage.
• Deliver in the morning. The temperature difference between an 8am delivery and a 2pm delivery in January is larger than anything else on this list.
• Dowel and centre-support anything tiered, including short tiers you would get away with in winter. Heat softens the structure that was holding the weight.

Ask the venue where the cake will sit

Get a written answer to one question before you agree a delivery time: where exactly is the cake going to stand, and is that space air conditioned?

A marquee is an oven. An outdoor reception in full sun in January is not a place a butter-iced cake survives an afternoon. A cool room changes the whole plan and most venues have one, but only if you ask early enough to book it.

Photograph the cake at handover, in position. Not as a legal manoeuvre. A cake that stood in the sun for three hours and a cake that was damaged in transit look similar in a photo taken at 9pm, and only one of them is yours.

What to steer customers toward, and away from

Away from, in December and January:

• Naked and semi-naked cakes with exposed cream or soft buttercream.
• Fresh cream, custard and mousse fillings, which give you the least margin for error on a hot day.
• Buttercream flowers and piped detail, which lose definition first.
• Isomalt and sugar glass, which go sticky in humidity within hours.
• Delicate chocolate work as the main feature.

Toward:

• Ganache-covered or fondant-covered tiers.
• Curd, jam, caramel and ganache fillings.
• Fresh fruit and sugar flowers rather than piped ones.
• Pavlova, trifle and other formats meant to be assembled at the venue. Both countries already have a summer Christmas dessert tradition. Lean on it rather than fighting to make a northern hemisphere centrepiece survive January.

Offer the alternative before they ask for the thing that will fail. A customer who has already fallen in love with a photo of a naked cake in a marquee is a much harder conversation than one you steered ten minutes earlier.

The business side of a summer peak

Cash flow inverts. You buy the ingredients in November and get paid across December, and then January arrives and both countries effectively shut down. New Zealand in particular goes quiet from Christmas until well into January. Plan the January float in November, not in January.

Publish a hard cutoff and a shutdown. Everyone in your supply chain is closing too. Your cutoff needs to sit far enough ahead of your suppliers' closures that a missing delivery does not become a cancelled order.

Your staff want the same week off you cannot give them. Agree it in October. The public holiday calendar differs between the two countries and between Australian states, so check the dates that apply to you rather than assuming.

If you use ibakepro, delivery time slots are the practical lever for the morning-delivery rule: cap the number of December deliveries that can land in each window, and close the afternoon windows entirely for the weeks where the afternoon is not survivable.

What to change this year

Set your December delivery windows before you take a single December order. Decide now which designs you will not accept for outdoor summer events. Pick your ganache ratio for January rather than reusing the one from June. And put the box-stays-shut rule in writing on the delivery note, because the person who opens it will not be you.