Strawberry tart

My second bake of the year, yes, only the second one surprisingly. So, after almost 2 months with no baking, I decided to make something simple just to make sure I can still bake. I was originally going to make a rhubarb and strawberry tart, but I couldn't get hold of any rhubarb. 

Ingredients (for 9 inch tart tin)

• 80g + 40g unsalted butter (separate)
• 30g icing sugar
• 190g + 15g plain flour (separate)
• 25g + 50g corn flour (separate)
• 750g strawberries
• 130g + 50g caster sugar (separate)
• 500ml milk (semi-skimmed or full fat)
• 5 large eggs

1. Cut butter and sift icing sugar, 190g plain flour together and rub with finger tips until it resembles breadcrumb (or pulse with mixer)
2. Add 1 whole egg and 1 tbsp of cold water and combine by hand until it forms a smooth dough, at this stage, it should not stick to your hands 
3. Roll out pastry dough to 2-3mm thick and place inside tart tin, softly press dough against the sides and leave the extras from the sides for now
4. Prick the base of pastry evenly with a fork and chill in the fridge for 30 minutes, meanwhile, pre-heat oven to 190 degrees C (170 fan)
5. Place a piece of parchment paper on the pastry and line with baking beans to prevent pastry from rising and allow an even bake of the base
6. Blind bake for 10 minutes, take it out of the oven and trim off the excess from the sides with a sharp knife, careful as the pastry is very delicate at this stage
7. Blind bake for another 5 minutes, the base should be dry at this stage, if not, return to oven for another 2 minutes and keep going until the pastry base is dry beneath the baking beans
8. Remove baking beans and parchment paper and bake for another 5 minutes, or until the base is golden
9. Beat 1 egg in a bowl
10. Remove pastry from oven and lightly brush the beaten egg onto the base and sides of pastry case
11. Return to the oven and bake for another 5 minutes, or until the pastry case is golden in colour
12. Take pastry out of oven and let it cool to room temperature
13. To make strawberry sauce, wash and quarter 250g of strawberries (if you want strawberry and rhubarb, replace 100g strawberry with chopped rhubarb)
14. Place strawberries in saucepan with 50g caster sugar and 3 tbsp water over medium heat until it simmers
15. Take a small amount of the strawberry juice out of saucepan and beat in the corn flour until it is smooth and thick
16. Add a bit more strawberry juice to the thickened paste until it becomes running
17. Return all of the juice and cornflour to the saucepan, heat and beat until it is thick
18. Put in strawberry sauce in a clean bowl to cool down
19. You should have some beaten egg left, add 3 egg yolks, 130g sugar and 50g corn flour to the eggs and mix until thick
20. Heat milk until simmering and add gradually the milk to the egg mix and keep whisking at the same time until half of the milk has been added
21. Transfer the runny custard to the remaining milk back in the saucepan and put it over low-medium heat, continue whisking the whole time 
22. Continue heating until the custard simmers and starts to thicken, it should still be runny, but should be thicker than double cream consistency
23. Add 1 tsp of vanilla extract to the custard and stir it in
24. Continue beating until the custard is very thick
25. Take pastry cream off the heat and add 40g unsalted butter, stir it in until it has completed melted 
26. Cool custard to room temperature
27. Spread the thickened sauce evenly to the bottom of the pastry base and set in fridge for 1-2 hours
28. Pipe the pastry cream on top of strawberry sauce and layer chopped strawberries on top however you like
29. Brush leftover strawberry jam on top of the strawberries for glazing

La Burdick, Boston, MA, USA

This place is a chocolatier specialist, so as expected, their main products are pre-packaged chocolates of various flavours. However, they do have a good variety of chocolate desserts too. I didn't purchase any chocolates as that wasn't the reason of my visit.

Linzer torte

Let's start with the linzer torte, visually, it looked very appetising with all those roasted nuts and a good layer of raspberry in the middle. It was packed with almond flavour, but the hazelnut didn't come through strongly, in fact, you really had to search for the hazelnut flavour. The nuts on top were well roasted and crisp. However, the linzertorte for me would have to be more delicate and crumbly. This particular one was quite solid and the mixture may have been overworked, giving it more of a chewy and hard texture. The flavour was absolutely fine. 

The Burdick

The cake was quite solid, and was not as moist and soft as I had expected. The rum flavour came through nicely and complemented the flavour well. The design was simple and effective. The structure was held very well for ALL of the cakes there and they all looked very attractive. However, I suspect the structure of all the cakes were so sturdy because the cake itself was harder and less likely to collapse . I'm definitely someone who would go for taste before appearance. Though, saying that, the cake was good, but is it good enough to inherit the name of the shop? Personally, I don't think it is.

Mocha cake

Very similar to the burdick in terms of structure and texture. The sponge had a very close texture, but because of the fact each layer is sliced so thin, you may not notice, especially if you had a soft layer of cream/mousse in between the layers. The major problem of this cake is the stiff coffee cream. It was too hard, perhaps beaten too much. A good soft cream would hide the downfall of the sponge, but this cream couldn't do that because it was very hard itself. Despite saying that, the aroma and taste from the coffee was very good and it was lovely. If the texture itself can be improved slightly, this will be a very good cake.

Lemon and chocolate cake

I've said it before and I will say it again, lemon and chocolate go very nicely together and this cake was a delight, flavour wise. Texture on the other hand, suffered the same problems as the ones I mentioned above. The lemon cream here is softer and did in fact mask the downfall of the cake somewhat. This is definitely worth trying and I did feel I wanted more after finishing it.

Overall impression: 6/10
The burdick: 6/10
mocha cake: 6.5/10
chocolate lemon cake: 7/10
Linzertorte: 5.5/10

Maria's pastry, Boston, MA, USA

Yet another beautiful weekend in Boston, sunny, not a single cloud in the sky and yes, still -10 degrees C here. I found this lovely Italian pastry shop at Haymarket whilst I was, well, searching for the market. It has a good range of pastries and biscuits, but I couldn't see any cakes there and they also sell pre-packaged baked goods in there too. They do the baking in a separate room at the back of the shop and the place has generally received good reviews. So, I thought, let's give it a try. It's nice to visit local bakeries that aren't part of a chain, which can mass produce products and slip up on the occasional quality control. Unlike the previous visits to other places, I only picked up a range of pastries instead of going for things from across the disciplines in baking.

The first thing I tried was the Baba rum, or how we British call it, the rum baba. Don't know why we switch the order of words around to be honest. The actual baba was good, the texture feels that it has good volume, good aeration and a very slightly harder skin on the outside. It was filled with pastry cream. Variations from some cultures will add some fruit too, but not in this one, which is not an issue. Though both the baba and the cream were good, the overall impressiveness was ruined somewhat by the rum syrup. It was not as sweet as I had hoped and it has a quite distinct sour after taste, which didn't appeal to me very much. If it was made slightly sweeter and less sour, it would be a much better baba I think. Presentation wise, it was fine, but the pastry cream didn't stick to the baba very well and when you eat it, the two components separate. 

Next was the mille-feuille. Honest opinion, the pastry and structure were both very good. It held together very well. Sometimes the whole thing just disintegrates and difficult to eat because it's extremely messy. The flaky pastry built up a multitude of layers and was crisp, but not solid like some mille-feuilles, making it much easier to eat. The pastry cream inside was sweet and delicate, but too much custard and not enough vanilla, also, the cream was slightly too thick for my liking. I was looking for the flavourful caramelisation of the sugar on the pastry, but I couldn't find any, so the pastry on its own would be quite bland without the custard cream. However, the whole thing was sweet enough, shame about the caramelisation of the pastry though. 

Also, I had the custard slice. I thought the custard slice is just what americans call the french mille-feuille, but the one I had looked and tasted slightly different to the mille-feuille I bought. The pastry was the same, the custard was slightly sweeter I found, but that could be just me. And there is a very thin layer of sponge in the middle, which was interesting. This is something I'm definitely going to try when I get the opportunity. Overall, just like the mille-feuille, good structure, good pastry, good custard, let down by the caramelisation of the pastry. 

Chocolate filled cannoli, I don't have this very often, so can't say I'm very good at judging it. But, I thought it was good, it's not overly sickly or sweet, the sweetened ricotta also held well inside, which is, just like they said, filled upon purchase. The shell was crisp, has a very nice flavour and at the same time complemented the ricotta well. I quite enjoyed this. I always find the ricotta in cannoli a bit lumpy though, maybe I'm just too used to creamy cheese. 

The appearance of the sfogliatelle was impeccable, and the texture was good too. The cream was fluffy and sweet. It is quite crunchy and not really something you can eat with a knife and fork without making a mess (talking from experience here). But overall, it is rather tasty.

Finally, I got an apple strudel from the shop as well. The pastry itself wasn't very flaky as I would expect from a strudel. The pastry may not have been rolled out thin enough, it actually felt more like an apple turnover in parts. So, as an apple turnover, it is very good. It wasn't overly sweet, but as a strudel, it was let down by the pastry unfortunately.

Overall impression: 6/10
Baba rum: 5/10
Mille feuille and custard slice: 7.5/10
apple strudel: 5/10
sfogliatelle: 7/10
cannoli: 8/10

Mille-feuille bakery, New York City, USA

I'm just going to say it, this bakery is very good and definitely worth a visit. No, I wasn't paid to say this. I identified the place from the number of positive comments online, and it was quite close to where I stayed in New York anyway, so thought I'd give it a go. The bakery was quite small and there weren't a huge range of goods there, but still, the things on display were decent. 

The place just seemed clean and simple, nothing extravagant, but had a nice french cafe feel to it. The girl at the counter was very smiley, which is always good to see. Cafes and patisseries are meant to be filled with happy people. I sat down with my food there for about 30 minutes, during that time they got a few customers through and they sounded like they go there quite often. A little girl popped in with dad and got some macarons too and the whole atmosphere was just so sweet and homely.

One slight thing is that although they have ovens on site, all of their baked goods are made in a kitchen in Brooklyn. When you go in, you don't get the attractive fresh bread and buttery smell that you sometimes get in bakeries. 

Moving onto their baked goods. It's called the mille-feuille, so I just had to try the mille-feuille. It was a simple one, with vanilla cream and dusting of icing sugar. The pastry had good flake and good caramelisation, each layer within the pastry was clear and well defined. The pastry cream was light and complimented the pastry very well. However, one down side is that the puff pastry did feel a bit over baked and slightly burnt in areas and tasted a little bitter. Though, it wasn't such a big problem, it could be overlooked quite easily. 

The chocolate fondant was very moist and the sponge was light and just very chocolatey. Was kind of expecting a gush of melted chocolate to seep out when I cut into it, well, that didn't happen, which was a bit disappoint. Nonetheless, as a chocolate sponge, it was good. 

I tried the macarons too, there were many flavours. My favourite one has to be blackcurrant, passion fruit and salted caramel. So, quite simple flavours, but they tasted SO good! It was just the right size, delicate and the middle is not overly chewy. I really smiled after having just one, and it has been a LONG time since I smiled after trying something at a bakery. It's amongst the best macarons I've tasted and I've tried them from quite a few places. Shame that some of them had crached tops, but these are not cracks from the baking, more like they were so delicate that the shell on the surface broke during transport and ruined the appearance slightly. 

Last but not least, the raspberry financier. I felt it could do with a little bit more raspberries, but overall, it was too bad. The almond flavour came out quite strong and it was lovely. However, the colour and taste suggest to me that the butter has not been heated for quite long enough to give the financiers the distinctive caramelised flavour. It didn't feel like a financier, just an almond cake. 

I would definitely visit this little place in lower Manhattan again if I get the chance. The price is relatively reasonable and the standards of goods there are definitely above your regular bakery and cafe. 

Over impression: 8/10

Macarons: 9/10 

Chocolate fondant: 6.5/10

Mille feuille: 8/10

financier: 6/10

Pasticceria Rocco, New York City, USA

This is a very busy cafe/patisserie and despite their business, the service was good and attentive. The selection of products there were also very good. Ranging from cakes to various pastries and lots of biscuits. And for such a busy and popular cafe, the prices are very reasonable. But, unfortunately that's all the nice things I can say about it. 

I tried a few things there and honestly, none of them really stood out very much. A few things did look very attractive on menu, but didn't quite live up to expectations. Bearing in mind, I haven't eaten since 9am that day and I arrived at the shop at 3pm, so I was starving and would be happy with anything. 

Let's start with the key lime tart, the filling was actually good. You get the zing with it and the sweetness was relatively balanced too. You can get an overpowering sourness sometimes, but fortunately, this was good. However, the pastry let it down. It's a shortcrust pastry, so you would expect it to be short, it was overworked and quite hard, which is not quite right for a shortcrust pastry. In fact, if the pastry was thinner, the downfall of the pastry wouldn't have been that obvious, however, the pastry was VERY thick, I didn't have a ruler with me, but just by looking at it, I'm pretty confident to say it was probably about 1cm thick, which is almost as thick as the filling itself! 

Then I had the turtle cheesecake. So, the description was a new york cheesecake topped with pecans, caramel and chocolate. My instant thought was "hey, I'm in New York, let's try the new york cheesecake", and the combination sounded nice too. Again, it was quite disappointing. I wasn't expecting a huge amount of flavour in the cheesecake itself, but it was literally a plain cheesecake. I think it would be a lot better if they had incorporated the flavour of the topping into the cheesecake itself. But rather, the topping was lose, fallen apart and didn't quite hold its shape on the cheesecake. Furthermore, perhaps from the weight of the topping crushing down, the cheesecake also felt a bit dense. Finally coming to the biscuit base, I could barely find anything. It's not supposed to be a huge amount of biscuit, but, the biscuit there was extremely thin. Great if you don't like the biscuit base anyway, but I think it would be great if they could double the depth of biscuit there. 

The rum baba I had was thorough soaked in sweet rum syrup, the dough was actually alright to the baba, but oversoaked perhaps, it was EXTREMELY wet and soggy. Imagine the texture of your morning cereal bathed in milk for a few minutes. That kind of texture. 

Finally, I had a pistachio biscotti. Can't really taste the pistachio, you see a lot of green in there, but can't really pin down the actual pistachio taste and there was certainly hardly any pistachio nut in there that I could see. So, the flavour was lacking, just tasted sweet and frankly, quite artificial. 

It's a bakery with a good range of products, though I wouldn't say the goods were particularly outstanding. Worth popping in for an afternoon tea if you are in the area, but don't expect too much. 

Overall impression: 4/10

Key lime tart: 5/10

Rum baba: 4/10

biscotti: 4/10

cheesecake:5/10

Bova's bakery, Boston, MA, USA

Yet another bakery I looked up and this one also received some fairly good reviews by locals. Their name is definitely not as big as the big bakeries and patisseries in Boston, but I think the family ran and rustic nature won me over. The street the bakery is on is tucked away and it's not that easy to find. It wasn't packed as expected, but it did have a wonderful smell of baked goods inside. Their baked goods aren't fancy decorations, what you see is what you get and I like that. They have a nice range of bread on display, but unfortunately I only picked up a loaf of ciabatta bread there. 

Again, I picked a few nice looking baked goods ranging from bread to cake and pastry. I don't have a picture for the bread, because I finished the whole loaf before I realised I didn't have a picture, but it was a good loaf of ciabatta bread, it had a nice crust to it and the flavour wasn't too strong, but adequate . I'm not a huge fan of heavily yeasted and fermented bread, so this for me was perfect. There are large irregular air pockets in the bread as well. So as far as ciabatta goes, it ticked all the boxes. 

The cheesecake was what I had next, it was a plain cheesecake, there are other flavours, but I stuck with the plain one, as I think that really tells you of the bake itself. Strong flavours can mask a multitude of sins as they say. The cheesecake was not too heavy, but nicely cream and soft and the biscuit base held together well. I would have liked it to be a bit more buttery, but that's personal preference. So the cheesecake was nicely made too. 

Moving on the the sfogliatelle, at least I think that's what it was, it didn't really have the layers I was expecting from the appearance. It was quite tough actually, but since I've got no idea what it should be like I can't really tell. 

The eclair was strange. The pastry itself is fine and you can't really go wrong with the chocolate topping. But I felt the pastry cream filling was a bit too much and heavy for my liking, it just tipped the balance over from something that is very good to something that is just ok. 

The fruit tart was also very weird, not in terms of the fruit or the creme patissiere, but the pastry. It's not shortcrust pastry, it's very hard, very sweet and definitely not a meringue. It made it very difficult to eat as well. I must say, I'm a big fan of fruit tarts in general, but I didn't really enjoy this one. 

Over all impression: 6/10

Ciabatta bread: 8/10

Plain cheesecake: 8/10

Fruit tart: 4/10

chocolate eclair: 6/10

sfogliatelle:  can't tell, don't know what it's like, but as far as how much I enjoyed it, 6/10

Flour Bakery, Boston, MA, USA

THE Flour Bakery, it's one of the top and most recommended bakery by various places and websites on the internet. It's also quite a popular bakery amongst the locals as well (says my colleague, who is a PhD student like me and also quite a keen baker). To be honest, I wasn't really sure what to expect, and  certainly didn't want everyone to hype it up too much, that tends to get me over-excited and most of the time, when things are too hyped, they don't tend to live up to expectations. 

Flour bakery has 4 branches: South End, Back Bay, Fort Point Channel and Central Square. From what I gathered, they sell pretty much the same things. Flour Bakery is owned by Joanne Chang, who is a graduate from Harvard University, with a degree in applied mathematics and economics and left to train in New York, but you can read her profile yourself really on her bakery's website. The bakery itself was featured in Gourmet, the New York Times and also winner of Boston magazine's best bakery 4 times. 

I did a little research on what to get before I went, you know searching for the specialties. Almost straight way, I found their Sticky Sticky Bun was featured on "Throwdown! With Bobby Flay". If you don't know what it is, don't worry, I didn't either until I looked it up. It's basically a TV program featuring a celebrity chef challenging chefs at relatively renowned restaurants to their own signature food and then they decide who won. So the battle of Joanne Chang VS Bobby Flay, Joanne won in with her sticky sticky bun recipe. Another thing that she mentioned was her pain aux raisin, which is something she loves. So the sticky bun and pain aux raisins were the two things I knew I had to try before I even went. 

When I got there, the first impression was very good. The design was simple, not too extravagant, friendly staff and also, filled with families and little children, it's generally a very warm atmosphere I thought. Moving onto the bakes then, which I'm sure you are dying to hear. 

Pain aux raisin, gosh, this was a master piece! It was delicious and soft, and sometimes you can get an overpowering buttery flavour, but this one is well balanced and it's just perfect as far as the pastry goes. However, the slight down side for me was, I would have preferred a bit more raisins in there, I would have a bite of the pain aux raisin expecting to have each bite, not filled, but contains a few raisins. But with this one, I kind of just stumble on a few every now and then. But nonetheless, it is very good!

Now the Sticky Sticky Bun, not sure why sticky appears twice, I thought they just accidentally put sticky in there twice, but apparently it's what it's really called. Anyway, the bun was very soft and there was a very generous amount of topping, and I mean VERY generous amount of it. So much that a lot of it seeped into the actual bun. When you cut into it, 20% of the bun, on the side closest to the topping was wet and softened by caramel topping.The caramel and the nuts on top go very well together and the brioche was very nicely done too, some of the best I've tried. However, it is quite heavy, there is a lot of caramel and for some, it could be too much, I would definitely recommend trying this, but make sure it's the 1st thing you try and with a large of cup of tea coffee with it too. 

Chocolate tartlet, simple, good shortcrust pastry, nice chocolatey sweet filling, what more do you need to know?

Chocolate roulade, the surface was so shiny, I was blinded by the light reflected off it, ok, that's slightly exaggerated, but it did look very good. The roulade itself was very light and full of chocolate flavour, which is exactly how it should be, I couldn't fault it really, even the rolling was good. 

Raspberry gateaux, I must say, this kind of disappointed me, the cake itself seemed over baked, that or something in the mixture process didn't go right, it felt quite solid when you bite into it. The flavour combinations was great, the zing from the raspberries really hit your tongue from the word go and the sweet cake then neutralises the sourness quickly. But for me, the texture of the cake was wrong. 

Triple chocolate mousse, it's essentially a chocolate teacake. The chocolate dome was well done and shiny and it kept its shine for quite a bit as well, which I was impressed with. The middle is filled with very light chocolate mousse and the bottom a thin layer of chocolate sponge. It was a delight to eat. But I think part of me did think the mousse was too light, if it was slightly stiffer, it would be easier to cut and get a better definition from each cut. Each individual component of the teacake was well made, but I'm just not sure whether consistency for the mousse was right when combined with other other components. 

Impression: 8/10

Pain aux raisin: 9/10

Sticky sticky bun: 8/10

Triple chocolate mousse: 6/10

Raspberry cake: 4/10

Chocolate roulade: 8/10

Chocolate tartlet: 8/10

Baking science over the next 6 weeks

Hi readers! Thank you for visiting my blog and I hope you have found something to your fancy or useful here! 

Over the next 6-7 weeks, there will NOT be any new recipes here as I will be working in Boston and unfortunately my temporary flat there does not have an oven and only has a very small hot plate. There will instead, more updates on baking sciences, something I've been trying to put together to encourage scientific understanding by applying it on baking. 

If there are things in particular people would like to find out more, whether it is different types of flour, fats, what eggs do in a cake, different types of sugar etc, put a comment here and I'll do my best to find out more about it and explain it here! 

Paul Hollywood's 8 strand plaited loaf

The recipe is on the BBC website. It is easy to follow and it works really well, so I won't go through the recipe again here.
Link to recipe: http://www.bbc.co.uk/food/recipes/eight-strand_plaited_57815

Tip
When it says roll out each piece to 40cm, make sure it's thin and 40cm or even slightly longer, otherwise it will be difficult to plait towards the end and you will have quite a short loaf of bread like mine!

Also, it says 10g salt in this recipe, I actually find it a bit too salty for my liking, so if you prefer your bread more bland, reduce it to 5g.

Yeast

Aha! Biology! Something that I do (kind of) at last! No, I don’t actually work on yeasts or any sort of microorganisms and no, I don’t work on metabolisms at all. If there are specialists out there reading this, please do correct me if you spot any mistakes. 

Back in the days I was at school (gosh, just over 4 years ago), I was only told of the 5 kingdoms, followed by the phylum, class, order, family, genus and lastly, species. Of course, you always find out that whatever you learned at school is not entirely the whole story and before long, you get the addition of the 3 domains on top of the 5 kingdoms. We won’t concern ourselves with these hugely complicated evolutionary genetics, but I am going to describe the lineage of baker’s yeast, which belongs to the fungi kingdom under the eucaryota domain. 

Fig 1

Fig 1 Phylogeny of baker’s yeast S.cerevisiae.

Yeast is a type of unicellular fungus and baker’s yeast is almost entirely formed by the species, Saccharomyces cerevisiae. The “Saccharo” part means sugar and “myces” refers to fungus. The species name, cerevisiae, is derived from the name Ceres, the Roman goddess of agriculture. Don’t worry, I won’t dwell on the history of yeast at all, as I don’t even know them myself.

Yeast is not only involved in bread making, it is also used in the production of alcohol, cheese and various recombinant human proteins including antibiotics. This very useful organism ferments sugar, or fermentable sugar to form ethanol and carbon dioxide (CO₂) (Fig 2).

Fig 2

Fig 2 Aerobiosis and anaerobiosis following glycolysis. All species under the animalia kingdom can carry out the aerobiosis reaction following glycolysis into the kreb’s cycle and the electron transport chain to generate ATP to provide energy. However, unlike mammals, yeasts are capable of alcoholic fermentation, using the pyruvate generated to form ethanol and CO₂. Diagram taken from Alba-Lois and Segal-Kischinevzky (2010).  

From figure 2, we see that yeast is capable of producing CO₂, which is trapped in the matrix of bread dough formed by gluten, causing it to rise. The reaction requires glucose, but glucose is not readily available in the mixture of flour, water, salt and yeast. Flour contains starch, which is a large complex polysaccharide, containing many monosaccharides joined together. Glucose and fructose are released from the breakdown of starch; glucose enters glycolysis (Fig 2) directly, whilst fructose must be converted to glucose before it can enter the pathway.

Although S. cerevisiae is the dominant species used in both baking and brewing, there are different strains that control which yeast is used. Strain is used to distinguish microorganisms of the same species, which have very similar genetic make up, but may have specific mutations within their genome to adapt to a specific environment and subsequent changes in their phenotype of functionality. For example, it has been described that a species is a collection of different strains that show at least 70% cross-hybridisation, i.e. when the 2 strands of DNA are separated from two different organisms, at least 70% of the DNA from one organism will anneal or bind to the DNA of the other organism (Wayne et al, 1987) and this concept is generally applicable to the bacterial domain (Brenner et al, 2000).

Brewers’ yeast and bakers’ yeast behave very differently and they certainly belong to different strains of S.cerevisiae. Bakers’ yeast can be divided into three main categories: active dry yeast, instant dry yeast and compressed (cake) yeast.

Compressed yeast is made by a series of dehydration and literally compression processes after fermentation to concentrate the active yeast into a block. This yeast is alive and active and therefore, is much more prone to “death” and needs to be kept refrigerated in many cases. Even then, the yeasts don’t tend to last more than a few weeks. However, it has better leavening capacity compared to the other two yeast types and generates a weaker fermented flavor.

Active and Instant dry yeast are very similar. They are both dried yeasts, which mean they can be stored at room temperature and for a much longer period of time before they lose their leavening properties. These yeasts are not active immediately; they are in their dormant form. Many fungus become dormant when their surrounding environments become unfavorable, this process allows them to protect themselves from germinating or reproducing in undesirable conditions and conserve energy until time for growth. Active dry yeasts are in granules and needs to be soaked in water to activate before using in a dough. Instant yeast on the other hand, is elongated and therefore, has a larger surface area for water uptake and can be incorporated into the dough directly, but the two yeasts act in very similar ways if not identically once activated.

Yeasts are living organisms, and they need to be kept alive if you want it to do their job. Therefore, temperature and osmolarity of their surroundings are very important in maintaining their efficiency and liveliness. Yeasts work best at around 40 degrees C, but allowing it to ferment at lower temperature at about 30 degrees C will allow the dough to rise slower but develop the flavor over a longer period of time, some even put the dough in the fridge to retard the efficiency of yeast action and proof for a much longer period of time. However, do bear in mind temperature at about 60 degrees C will kill most yeast, so when adding warm water to the mixture, make sure the temperature is well below 60 degrees. High level (concentration) of salt will also retard yeast actions and even kill them. I actually don’t know why this occurs, but I speculate it is due to the osmolarity of the surrounding and draws water out of yeast and dehydrate them and hence “kills” the yeast preventing them from fermenting.

Leaving the yeast to work and proof the dough over a longer period allows flavor to develop in the dough. This is a result of breaking down the starch of the flour. Yeast when they ferment and multiply as well as metabolize, it releases various metabolites include aldehydes and ketones that affect the flavor of bread.

That’s it for now. Maybe I’ll come back to this and add more to it soon.

References

Alba-Lois, L. & Segal-Kischinevzky, C (2010).  Yeast Fermentation and the Making of Beer and Wine. Nature education. 3(9): 17

Brenner D, Staley J, Krieg N (2000). Classification of prokaryotic organisms and the concept of Bacterial speciation. Springer; New York, NY: Bergey's manual of systematic bacteriology

Wayne L.G, et al (1987). Report of the ad hoc committee on reconciliation of approaches to bacterial systematics. Int. J. Syst. Bacteriol.37: 463–464