Cheese making
In parallel with the synthetic biology work, we are experimenting with cheeses made from powdered purified casein, and using vegan oils to replace milkfat. This page documents our cheese-making efforts.
Electric cheese cave
Most hard cheeses that are the least bit interesting need to be aged at colder than room temperature and high humidity.
We've built a wifi-enabled cheese cave out of a modified wine chiller.
Cheese press
ToDo build one. I am working on this Juul (talk) 12:31, 8 April 2014 (PDT)
Rennet
We're using microbioally produced pure chymosin. It's what industry uses for most cheeses and it's also the most effective and preferable rennet for most hard cheeses.
We've purchased Chr Hansen CHY-MAX from The Cheese Maker online store.
This is getting a bit close to its expiration date and Chr Hansen has a new and better second-generation chymosin called CHY-MAX M. Which is also available from The Cheese maker. Perhaps we should order it.
Milk-fat / Oil
For non-vegan comparison experiments we can use ghee, but for actual vegan cheese we need a milk-fat substitute.
It may be hard to find a suitable vegan substitute. What are the important properties?
We can probably assume that melting point (stability at room temperature) is an important factor. It may also be that interaction with caseins is important for micelle formation. This should be easy to test though.
Palm Mid Fraction Oil (PMF)
- Melting point: 35-36C
- No strong flavors
- Concerns about sustainability of palm oil farming
More info on the different types of palm oil.
Cocoa butter equivalents (CBE)
These are fats rich in symmetrical disaturated TAG (SUS) that behave like cocoa butter in all respects and are able to mix in all proportions with cocoa butter. The desirable charac- teristics of cocoa butter are due to the SUS TAG, which provide a suitable melting point and solid fat content, resulting in rapid melt in the mouth and cooling sensations. Palm mid-fraction (PMF), which has a high content of POP, is easily formulated with other SUS fats for chocolate products (Berger 1981). About 70–80% PMF with 20–30% shea or sal stearin, or 60–65% PMF with 20–30% shea or sal stearin and 15%–20% illipe, are suitable for plain chocolate and for milk chocolate with 15% milk fat. The compatibility of cocoa butter (CB) and CBE is affected by the addition of milk fat and its fractions into the product (Sabariah et al. 1998). Eutectic interactions between anhydrous milk fat (AMF), CBE and CB were noticeable due to the different polymorphism encountered in these fats. Cocoa butter-like fats can also be formulated with interesterified oils. Blends suitable for butter-cream fillings in biscuits may be formulated from palm stearin/palm kernel olein (25:75) or palm stearin/palm kernel olein/palm kernel oil (25:37.5:37.5) (Noor Lida et al. 1997).
- From Vegetable Oils in Food Technology - Composition, Properties and Uses
Cacao butter
- Melting point: 34 to 38C
- Flavors may be a problem
- Expensive
Coconut butter
- Melting point: ~25C
- Flavors may be a problem
Fully hydrogenated oils
We could change melting point of oils with hydrogenation. This isn't popular due mostly to concerns about trans fats, but trans fats should only be present in partially hydrogenated oils. It seems that these "bad" oils are not easy to buy in small quantities. It may just be that no-one advertises their product as "hydrogenated".
We probably can't hydrogenate oils ourselves, since it requires bubbling hydrogen through the oil at high temperatures in the presence of a metal catalyst :/
Lactose
Since there are no vegan sources for lactose, and since Lactic Acid Bacteria (LAB) are an important part of cheese-making, we will need a replacement.
LAB can grow on other sugars, but we do not know if their expression profile or growth rate will be different or whether this will affect the taste of the cheese. We can do two things:
- Make cheese with lactose-free milk vs. lactose-free milk with lactose added back in.
- Research to understand LAB and its use in cheese better.
For the non-vegan control, we can buy powdered lactose. We can also easily get [http://www.lactaid.com/ lactose free milk, but I'm fairly sure it still has some lactose. We may be able to break down most of the remaining lactose by adding a lactase enzyme supplement.
Casein
There is a protein supplement product available that is advertised as 100% micellar casein at $28 for two pounds. It claims to be 100% non-denatured micellar casein with no additives. It's not molecular/lab grade, but it may be the best we can get.
Sigma-aldrich sells kappa-casein but it's only >=70% pure and costs $600 for 1 gram.