Given a paragraph about cooking, and a set of conversational question answers about the paragraph, answer a follow-up question from the paragraph. The paragraph has a prefix 'CONTEXT:'. Each conversation question has a prefix 'Q:' followed by answer prefix 'A:'. The final followup question has a prefix 'FOLLOWUP_Q:'.

[Q]: CONTEXT: There are a couple of things you can do to prevent sugar crystallising. You can add some glucose syrup, or you can 'invert' the sugar by adding some acid, namely cream of tartar. Both should be readily available, online if not at your supermarket. Cream of tartar is also useful when making meringue.  <sep>  Q: How can I prevent simple syrup from crystallizing? A: ou can add some glucose syrup, or you can 'invert' the sugar by adding some acid, n  <sep> FOLLOWUP_Q: what sort of acid would you recommend?
[A]: cream of tartar


[Q]: CONTEXT: I have seen this happening more than once. While I don't know the whole theory behind it, each time it happened, there was something just below the hole, let's call it "the lump". What I think happens is that the lump is too heavy. When the batter below it tries to rise, it doesn't have the strength to push up the lump. This could be combined with differences in heat transfer throughout the batter vs. on the batter-lump transition in preventing rising (I am certain they exist, but I don't know whether they have an effect at all). The result is a hole where the batter didn't rise, surrounded by nicely risen batter. As to where the lump comes from: you say "chocolate and pear cake". If you have pear pieces in the batter, right under the surface, they can do this. I have certainly seen it happen when the recipe includes fruit pieces in the batter. If there are no pear pieces, my second guess is badly dissolved flour. The directions for this type of cake normally include folding the whites very gently, and generally erring on the side of too little whisking. This could contribute to uneven batter texture, resulting in lumps. In the second case, the cake may have some less-than-pleasant pieces, but will still be mostly good. If it is fruit, the holes are purely a cosmetic problem. So not much harm done either way, unless you are shooting for a prize at a baking competition.  <sep>  Q: I baked a cake and it has holes in it why? A: each time it happened, there was something just below the hole, let's call it "the lump  Q: Was it because the batter was uneven? A: What I think happens is that the lump is too heavy  Q: Could it be uneven rising? A: When the batter below it tries to rise, it doesn't have the strength to push up the lump  Q: How could this be prevented? A: folding the whites very gently, and generally erring on the side of too little whisking  <sep> FOLLOWUP_Q: Anything else?
[A]: my second guess is badly dissolved flour


[Q]: CONTEXT: Firstly - shop-bought "packet" bread will keep for several days because it contains a lot of preservatives.In his excellent book Bread Matters, Andrew Whitley claims that home-made sourdough breads with very long rises have better keeping properties than home-made bread made with baker's yeast and short rises. This, he claims, is because the sourdough yeast cultivates a culture of friendly bacteria and an acid environment, all of which become natural preservatives. My experience seems to confirm this.Bread recipes containing egg, oil or milk tend to keep for longer than those without.As @SAJ14SAJ says, bread freezes very well. Loss of flavour in the freezer is not a commonly recognised phenomenon.One option is to slice a loaf of bread, bag it and freeze it. Take as many slices as you need at a time. It will defrost very quickly at room temperature, due to its low mass and high surface area.Another option is to make rolls, part-bake, and freeze. When you need them, take as many rolls as you need from the freezer, and place in the oven, to both defrost and complete the baking. You will get fresh baking smells and flavours from this.I suspect that home-made unleavened breads (pita, chapati, tortilla), without added preservatives, will not last long out of the freezer. Their advantage is that with no rise, they are so quick to make that they can be made fresh on-demand.  <sep>  Q: What kind of homemade sandwich bread or wrap lasts longest? A: Firstly - shop-bought "packet" bread will keep for several days because it contains a lot of preservatives  Q: But what lasts best that is homemade? A: In his excellent book Bread Matters, Andrew Whitley claims that home-made sourdough breads  <sep> FOLLOWUP_Q: What can I do to make homemade bread last longer?
[A]:
Bread recipes containing egg, oil or milk tend to keep for longer than those without